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RFE: reset the "lost" value as seen via 'auditctl -s' #3
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OK, this seems like a small patch but it has a big impact. Many system admins It would be easier for them if the cron job generating their daily report issues |
RFC patch submitted upstream: It still requires userspace support and a test case. |
RFC v2 patch posted upstream: |
@rgbriggs I'm thinking this change might also warrant a RFE wiki page, what do you think? |
@stevegrubb what do you think of the new audit record in Richard's latest patch (link below)? |
Add a method to reset the audit_lost value. An AUDIT_SET message with the AUDIT_STATUS_LOST flag set by itself will return a positive value repesenting the current audit_lost value and reset the counter to zero. If AUDIT_STATUS_LOST is not the only flag set, the reset command will be ignored. The value sent with the command is ignored. The return value will be the +ve lost value at reset time. An AUDIT_CONFIG_CHANGE message will be queued to the listening audit daemon. The message will be a standard CONFIG_CHANGE message with the fields "lost=0" and "old=" with the latter containing the value of audit_lost at reset time. See: #3 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Acked-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
Updated the RFE based on userspace implementation: https://github.com/linux-audit/audit-kernel/wiki/RFE-Reset-the-Lost-Record-Counter/e62b2f5f9855918439517227850ecf8db9185112 |
See: linux-audit/audit-kernel#3 https://github.com/linux-audit/audit-kernel/wiki/RFE-Reset-the-Lost-Record-Counter Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Created an acceptance test: linux-audit/audit-testsuite@7784fa7 |
Test case update (reset auditd after test): linux-audit/audit-testsuite@101fb3a |
The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b3 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ #234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 #1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink include/linux/skbuff.h:1767 [inline] #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue include/linux/skbuff.h:1783 [inline] #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] process_backlog+0x264/0x730 net/core/dev.c:4835 #3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 #4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] #4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
The locking in lirc needs improvement, but for now just fix this potential deadlock. ====================================================== [ INFO: possible circular locking dependency detected ] 4.10.0-rc1+ #1 Not tainted ------------------------------------------------------- bash/2502 is trying to acquire lock: (ir_raw_handler_lock){+.+.+.}, at: [<ffffffffc06f6a5e>] ir_raw_encode_scancode+0x3e/0xb0 [rc_core] but task is already holding lock: (&dev->lock){+.+.+.}, at: [<ffffffffc06f511f>] store_filter+0x9f/0x240 [rc_core] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&dev->lock){+.+.+.}: [<ffffffffa110adad>] lock_acquire+0xfd/0x200 [<ffffffffa1921327>] mutex_lock_nested+0x77/0x6d0 [<ffffffffc06f436a>] rc_open+0x2a/0x80 [rc_core] [<ffffffffc07114ca>] lirc_dev_fop_open+0xda/0x1e0 [lirc_dev] [<ffffffffa12975e0>] chrdev_open+0xb0/0x210 [<ffffffffa128eb5a>] do_dentry_open+0x20a/0x2f0 [<ffffffffa128ffcc>] vfs_open+0x4c/0x80 [<ffffffffa12a35ec>] path_openat+0x5bc/0xc00 [<ffffffffa12a5271>] do_filp_open+0x91/0x100 [<ffffffffa12903f0>] do_sys_open+0x130/0x220 [<ffffffffa12904fe>] SyS_open+0x1e/0x20 [<ffffffffa19278c1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 -> #1 (lirc_dev_lock){+.+.+.}: [<ffffffffa110adad>] lock_acquire+0xfd/0x200 [<ffffffffa1921327>] mutex_lock_nested+0x77/0x6d0 [<ffffffffc0711f47>] lirc_register_driver+0x67/0x59b [lirc_dev] [<ffffffffc06db7f4>] ir_lirc_register+0x1f4/0x260 [ir_lirc_codec] [<ffffffffc06f6cac>] ir_raw_handler_register+0x7c/0xb0 [rc_core] [<ffffffffc0398010>] 0xffffffffc0398010 [<ffffffffa1002192>] do_one_initcall+0x52/0x1b0 [<ffffffffa11ef5c8>] do_init_module+0x5f/0x1fa [<ffffffffa11566b5>] load_module+0x2675/0x2b00 [<ffffffffa1156dcf>] SYSC_finit_module+0xdf/0x110 [<ffffffffa1156e1e>] SyS_finit_module+0xe/0x10 [<ffffffffa1003f5c>] do_syscall_64+0x6c/0x1f0 [<ffffffffa1927989>] return_from_SYSCALL_64+0x0/0x7a -> #0 (ir_raw_handler_lock){+.+.+.}: [<ffffffffa110a7b7>] __lock_acquire+0x10f7/0x1290 [<ffffffffa110adad>] lock_acquire+0xfd/0x200 [<ffffffffa1921327>] mutex_lock_nested+0x77/0x6d0 [<ffffffffc06f6a5e>] ir_raw_encode_scancode+0x3e/0xb0 [rc_core] [<ffffffffc0b0f492>] loop_set_wakeup_filter+0x62/0xbd [rc_loopback] [<ffffffffc06f522a>] store_filter+0x1aa/0x240 [rc_core] [<ffffffffa15e46f8>] dev_attr_store+0x18/0x30 [<ffffffffa13318e5>] sysfs_kf_write+0x45/0x60 [<ffffffffa1330b55>] kernfs_fop_write+0x155/0x1e0 [<ffffffffa1290797>] __vfs_write+0x37/0x160 [<ffffffffa12921f8>] vfs_write+0xc8/0x1e0 [<ffffffffa12936e8>] SyS_write+0x58/0xc0 [<ffffffffa19278c1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 other info that might help us debug this: Chain exists of: ir_raw_handler_lock --> lirc_dev_lock --> &dev->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev->lock); lock(lirc_dev_lock); lock(&dev->lock); lock(ir_raw_handler_lock); *** DEADLOCK *** 4 locks held by bash/2502: #0: (sb_writers#4){.+.+.+}, at: [<ffffffffa12922c5>] vfs_write+0x195/0x1e0 #1: (&of->mutex){+.+.+.}, at: [<ffffffffa1330b1f>] kernfs_fop_write+0x11f/0x1e0 #2: (s_active#215){.+.+.+}, at: [<ffffffffa1330b28>] kernfs_fop_write+0x128/0x1e0 #3: (&dev->lock){+.+.+.}, at: [<ffffffffc06f511f>] store_filter+0x9f/0x240 [rc_core] stack backtrace: CPU: 3 PID: 2502 Comm: bash Not tainted 4.10.0-rc1+ #1 Hardware name: /DG45ID, BIOS IDG4510H.86A.0135.2011.0225.1100 02/25/2011 Call Trace: dump_stack+0x86/0xc3 print_circular_bug+0x1be/0x210 __lock_acquire+0x10f7/0x1290 lock_acquire+0xfd/0x200 ? ir_raw_encode_scancode+0x3e/0xb0 [rc_core] ? ir_raw_encode_scancode+0x3e/0xb0 [rc_core] mutex_lock_nested+0x77/0x6d0 ? ir_raw_encode_scancode+0x3e/0xb0 [rc_core] ? loop_set_wakeup_filter+0x44/0xbd [rc_loopback] ir_raw_encode_scancode+0x3e/0xb0 [rc_core] loop_set_wakeup_filter+0x62/0xbd [rc_loopback] ? loop_set_tx_duty_cycle+0x70/0x70 [rc_loopback] store_filter+0x1aa/0x240 [rc_core] dev_attr_store+0x18/0x30 sysfs_kf_write+0x45/0x60 kernfs_fop_write+0x155/0x1e0 __vfs_write+0x37/0x160 ? rcu_read_lock_sched_held+0x4a/0x80 ? rcu_sync_lockdep_assert+0x2f/0x60 ? __sb_start_write+0x10c/0x220 ? vfs_write+0x195/0x1e0 ? security_file_permission+0x3b/0xc0 vfs_write+0xc8/0x1e0 SyS_write+0x58/0xc0 entry_SYSCALL_64_fastpath+0x1f/0xc2 Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
See: linux-audit/audit-kernel#3 https://github.com/linux-audit/audit-kernel/wiki/RFE-Reset-the-Lost-Record-Counter Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
Dmitry reported a lockdep splat [1] (false positive) that we can fix by releasing the spinlock before calling icmp_send() from ip_expire() This is a false positive because sending an ICMP message can not possibly re-enter the IP frag engine. [1] [ INFO: possible circular locking dependency detected ] 4.10.0+ #29 Not tainted ------------------------------------------------------- modprobe/12392 is trying to acquire lock: (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock include/linux/spinlock.h:299 [inline] (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock include/linux/netdevice.h:3486 [inline] (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 but task is already holding lock: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock include/linux/spinlock.h:299 [inline] (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(&q->lock)->rlock){+.-...}: validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669 ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713 packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459 deliver_skb net/core/dev.c:1834 [inline] dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890 xmit_one net/core/dev.c:2903 [inline] dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923 sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308 neigh_output include/net/neighbour.h:478 [inline] ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228 ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672 ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545 ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985 __sys_sendmmsg+0x25c/0x750 net/socket.c:2075 SYSC_sendmmsg net/socket.c:2106 [inline] SyS_sendmmsg+0x35/0x60 net/socket.c:2101 do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281 return_from_SYSCALL_64+0x0/0x7a -> #0 (_xmit_ETHER#2){+.-...}: check_prev_add kernel/locking/lockdep.c:1830 [inline] check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] __netif_tx_lock include/linux/netdevice.h:3486 [inline] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_hh_output include/net/neighbour.h:468 [inline] neigh_output include/net/neighbour.h:476 [inline] ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:657 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 __read_once_size include/linux/compiler.h:254 [inline] atomic_read arch/x86/include/asm/atomic.h:26 [inline] rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline] __rcu_is_watching kernel/rcu/tree.c:1133 [inline] rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335 do_fault_around mm/memory.c:3231 [inline] do_read_fault mm/memory.c:3265 [inline] do_fault+0xbd5/0x2080 mm/memory.c:3370 handle_pte_fault mm/memory.c:3600 [inline] __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&q->lock)->rlock); lock(_xmit_ETHER#2); lock(&(&q->lock)->rlock); lock(_xmit_ETHER#2); *** DEADLOCK *** 10 locks held by modprobe/12392: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>] __do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336 #1: (rcu_read_lock){......}, at: [<ffffffff8188cab6>] filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324 #2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] spin_lock include/linux/spinlock.h:299 [inline] #2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] pte_alloc_one_map mm/memory.c:2944 [inline] #2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072 #3: (((&q->timer))){+.-...}, at: [<ffffffff81627e72>] lockdep_copy_map include/linux/lockdep.h:175 [inline] #3: (((&q->timer))){+.-...}, at: [<ffffffff81627e72>] call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258 #4: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock include/linux/spinlock.h:299 [inline] #4: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201 #5: (rcu_read_lock){......}, at: [<ffffffff8389a633>] ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216 #6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock include/linux/spinlock.h:309 [inline] #6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock net/ipv4/icmp.c:219 [inline] #6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681 #7: (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>] ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198 #8: (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>] __dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324 #9: (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at: [<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 stack backtrace: CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:52 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204 check_prev_add kernel/locking/lockdep.c:1830 [inline] check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] __netif_tx_lock include/linux/netdevice.h:3486 [inline] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_hh_output include/net/neighbour.h:468 [inline] neigh_output include/net/neighbour.h:476 [inline] ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:657 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline] RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline] RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline] RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147 RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000 R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25 R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000 </IRQ> rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335 do_fault_around mm/memory.c:3231 [inline] do_read_fault mm/memory.c:3265 [inline] do_fault+0xbd5/0x2080 mm/memory.c:3370 handle_pte_fault mm/memory.c:3600 [inline] __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011 RIP: 0033:0x7f83172f2786 RSP: 002b:00007fffe859ae80 EFLAGS: 00010293 RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970 RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000 R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040 R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
mipsxx_pmu_handle_shared_irq() calls irq_work_run() while holding the pmuint_rwlock for read. irq_work_run() can, via perf_pending_event(), call try_to_wake_up() which can try to take rq->lock. However, perf can also call perf_pmu_enable() (and thus take the pmuint_rwlock for write) while holding the rq->lock, from finish_task_switch() via perf_event_context_sched_in(). This leads to an ABBA deadlock: PID: 3855 TASK: 8f7ce288 CPU: 2 COMMAND: "process" #0 [89c39ac8] __delay at 803b5be4 #1 [89c39ac8] do_raw_spin_lock at 8008fdcc #2 [89c39af8] try_to_wake_up at 8006e47c #3 [89c39b38] pollwake at 8018eab0 #4 [89c39b68] __wake_up_common at 800879f4 #5 [89c39b98] __wake_up at 800880e4 #6 [89c39bc8] perf_event_wakeup at 8012109c #7 [89c39be8] perf_pending_event at 80121184 #8 [89c39c08] irq_work_run_list at 801151f0 #9 [89c39c38] irq_work_run at 80115274 #10 [89c39c50] mipsxx_pmu_handle_shared_irq at 8002cc7c PID: 1481 TASK: 8eaac6a8 CPU: 3 COMMAND: "process" #0 [8de7f900] do_raw_write_lock at 800900e0 #1 [8de7f918] perf_event_context_sched_in at 80122310 #2 [8de7f938] __perf_event_task_sched_in at 80122608 #3 [8de7f958] finish_task_switch at 8006b8a4 #4 [8de7f998] __schedule at 805e4dc4 #5 [8de7f9f8] schedule at 805e5558 #6 [8de7fa10] schedule_hrtimeout_range_clock at 805e9984 #7 [8de7fa70] poll_schedule_timeout at 8018e8f8 #8 [8de7fa88] do_select at 8018f338 #9 [8de7fd88] core_sys_select at 8018f5cc #10 [8de7fee0] sys_select at 8018f854 #11 [8de7ff28] syscall_common at 80028fc8 The lock seems to be there to protect the hardware counters so there is no need to hold it across irq_work_run(). Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The lag_lock is taken from both process and softirq contexts which results lockdep warning[0] about potential deadlock. However, just disabling softirqs by using *_bh spinlock API is not enough since it will cause warning in some contexts where the lock is obtained with hard irqs disabled. To fix the issue save current irq state, disable them before obtaining the lock an re-enable irqs from saved state after releasing it. [0]: [Sun Aug 7 13:12:29 2022] ================================ [Sun Aug 7 13:12:29 2022] WARNING: inconsistent lock state [Sun Aug 7 13:12:29 2022] 5.19.0_for_upstream_debug_2022_08_04_16_06 #1 Not tainted [Sun Aug 7 13:12:29 2022] -------------------------------- [Sun Aug 7 13:12:29 2022] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. [Sun Aug 7 13:12:29 2022] swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: [Sun Aug 7 13:12:29 2022] ffffffffa06dc0d8 (lag_lock){+.?.}-{2:2}, at: mlx5_lag_is_shared_fdb+0x1f/0x120 [mlx5_core] [Sun Aug 7 13:12:29 2022] {SOFTIRQ-ON-W} state was registered at: [Sun Aug 7 13:12:29 2022] lock_acquire+0x1c1/0x550 [Sun Aug 7 13:12:29 2022] _raw_spin_lock+0x2c/0x40 [Sun Aug 7 13:12:29 2022] mlx5_lag_add_netdev+0x13b/0x480 [mlx5_core] [Sun Aug 7 13:12:29 2022] mlx5e_nic_enable+0x114/0x470 [mlx5_core] [Sun Aug 7 13:12:29 2022] mlx5e_attach_netdev+0x30e/0x6a0 [mlx5_core] [Sun Aug 7 13:12:29 2022] mlx5e_resume+0x105/0x160 [mlx5_core] [Sun Aug 7 13:12:29 2022] mlx5e_probe+0xac3/0x14f0 [mlx5_core] [Sun Aug 7 13:12:29 2022] auxiliary_bus_probe+0x9d/0xe0 [Sun Aug 7 13:12:29 2022] really_probe+0x1e0/0xaa0 [Sun Aug 7 13:12:29 2022] __driver_probe_device+0x219/0x480 [Sun Aug 7 13:12:29 2022] driver_probe_device+0x49/0x130 [Sun Aug 7 13:12:29 2022] __driver_attach+0x1e4/0x4d0 [Sun Aug 7 13:12:29 2022] bus_for_each_dev+0x11e/0x1a0 [Sun Aug 7 13:12:29 2022] bus_add_driver+0x3f4/0x5a0 [Sun Aug 7 13:12:29 2022] driver_register+0x20f/0x390 [Sun Aug 7 13:12:29 2022] __auxiliary_driver_register+0x14e/0x260 [Sun Aug 7 13:12:29 2022] mlx5e_init+0x38/0x90 [mlx5_core] [Sun Aug 7 13:12:29 2022] vhost_iotlb_itree_augment_rotate+0xcb/0x180 [vhost_iotlb] [Sun Aug 7 13:12:29 2022] do_one_initcall+0xc4/0x400 [Sun Aug 7 13:12:29 2022] do_init_module+0x18a/0x620 [Sun Aug 7 13:12:29 2022] load_module+0x563a/0x7040 [Sun Aug 7 13:12:29 2022] __do_sys_finit_module+0x122/0x1d0 [Sun Aug 7 13:12:29 2022] do_syscall_64+0x3d/0x90 [Sun Aug 7 13:12:29 2022] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [Sun Aug 7 13:12:29 2022] irq event stamp: 3596508 [Sun Aug 7 13:12:29 2022] hardirqs last enabled at (3596508): [<ffffffff813687c2>] __local_bh_enable_ip+0xa2/0x100 [Sun Aug 7 13:12:29 2022] hardirqs last disabled at (3596507): [<ffffffff813687da>] __local_bh_enable_ip+0xba/0x100 [Sun Aug 7 13:12:29 2022] softirqs last enabled at (3596488): [<ffffffff81368a2a>] irq_exit_rcu+0x11a/0x170 [Sun Aug 7 13:12:29 2022] softirqs last disabled at (3596495): [<ffffffff81368a2a>] irq_exit_rcu+0x11a/0x170 [Sun Aug 7 13:12:29 2022] other info that might help us debug this: [Sun Aug 7 13:12:29 2022] Possible unsafe locking scenario: [Sun Aug 7 13:12:29 2022] CPU0 [Sun Aug 7 13:12:29 2022] ---- [Sun Aug 7 13:12:29 2022] lock(lag_lock); [Sun Aug 7 13:12:29 2022] <Interrupt> [Sun Aug 7 13:12:29 2022] lock(lag_lock); [Sun Aug 7 13:12:29 2022] *** DEADLOCK *** [Sun Aug 7 13:12:29 2022] 4 locks held by swapper/0/0: [Sun Aug 7 13:12:29 2022] #0: ffffffff84643260 (rcu_read_lock){....}-{1:2}, at: mlx5e_napi_poll+0x43/0x20a0 [mlx5_core] [Sun Aug 7 13:12:29 2022] #1: ffffffff84643260 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_list_internal+0x2d7/0xd60 [Sun Aug 7 13:12:29 2022] #2: ffff888144a18b58 (&br->hash_lock){+.-.}-{2:2}, at: br_fdb_update+0x301/0x570 [Sun Aug 7 13:12:29 2022] #3: ffffffff84643260 (rcu_read_lock){....}-{1:2}, at: atomic_notifier_call_chain+0x5/0x1d0 [Sun Aug 7 13:12:29 2022] stack backtrace: [Sun Aug 7 13:12:29 2022] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0_for_upstream_debug_2022_08_04_16_06 #1 [Sun Aug 7 13:12:29 2022] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [Sun Aug 7 13:12:29 2022] Call Trace: [Sun Aug 7 13:12:29 2022] <IRQ> [Sun Aug 7 13:12:29 2022] dump_stack_lvl+0x57/0x7d [Sun Aug 7 13:12:29 2022] mark_lock.part.0.cold+0x5f/0x92 [Sun Aug 7 13:12:29 2022] ? lock_chain_count+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? unwind_next_frame+0x1c4/0x1b50 [Sun Aug 7 13:12:29 2022] ? secondary_startup_64_no_verify+0xcd/0xdb [Sun Aug 7 13:12:29 2022] ? mlx5e_napi_poll+0x4e9/0x20a0 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? mlx5e_napi_poll+0x4e9/0x20a0 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? stack_access_ok+0x1d0/0x1d0 [Sun Aug 7 13:12:29 2022] ? start_kernel+0x3a7/0x3c5 [Sun Aug 7 13:12:29 2022] __lock_acquire+0x1260/0x6720 [Sun Aug 7 13:12:29 2022] ? lock_chain_count+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? lock_chain_count+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? register_lock_class+0x1880/0x1880 [Sun Aug 7 13:12:29 2022] ? mark_lock.part.0+0xed/0x3060 [Sun Aug 7 13:12:29 2022] ? stack_trace_save+0x91/0xc0 [Sun Aug 7 13:12:29 2022] lock_acquire+0x1c1/0x550 [Sun Aug 7 13:12:29 2022] ? mlx5_lag_is_shared_fdb+0x1f/0x120 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? lockdep_hardirqs_on_prepare+0x400/0x400 [Sun Aug 7 13:12:29 2022] ? __lock_acquire+0xd6f/0x6720 [Sun Aug 7 13:12:29 2022] _raw_spin_lock+0x2c/0x40 [Sun Aug 7 13:12:29 2022] ? mlx5_lag_is_shared_fdb+0x1f/0x120 [mlx5_core] [Sun Aug 7 13:12:29 2022] mlx5_lag_is_shared_fdb+0x1f/0x120 [mlx5_core] [Sun Aug 7 13:12:29 2022] mlx5_esw_bridge_rep_vport_num_vhca_id_get+0x1a0/0x600 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? mlx5_esw_bridge_update_work+0x90/0x90 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? lock_acquire+0x1c1/0x550 [Sun Aug 7 13:12:29 2022] mlx5_esw_bridge_switchdev_event+0x185/0x8f0 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? mlx5_esw_bridge_port_obj_attr_set+0x3e0/0x3e0 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? check_chain_key+0x24a/0x580 [Sun Aug 7 13:12:29 2022] atomic_notifier_call_chain+0xd7/0x1d0 [Sun Aug 7 13:12:29 2022] br_switchdev_fdb_notify+0xea/0x100 [Sun Aug 7 13:12:29 2022] ? br_switchdev_set_port_flag+0x310/0x310 [Sun Aug 7 13:12:29 2022] fdb_notify+0x11b/0x150 [Sun Aug 7 13:12:29 2022] br_fdb_update+0x34c/0x570 [Sun Aug 7 13:12:29 2022] ? lock_chain_count+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? br_fdb_add_local+0x50/0x50 [Sun Aug 7 13:12:29 2022] ? br_allowed_ingress+0x5f/0x1070 [Sun Aug 7 13:12:29 2022] ? check_chain_key+0x24a/0x580 [Sun Aug 7 13:12:29 2022] br_handle_frame_finish+0x786/0x18e0 [Sun Aug 7 13:12:29 2022] ? check_chain_key+0x24a/0x580 [Sun Aug 7 13:12:29 2022] ? br_handle_local_finish+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? __lock_acquire+0xd6f/0x6720 [Sun Aug 7 13:12:29 2022] ? sctp_inet_bind_verify+0x4d/0x190 [Sun Aug 7 13:12:29 2022] ? xlog_unpack_data+0x2e0/0x310 [Sun Aug 7 13:12:29 2022] ? br_handle_local_finish+0x20/0x20 [Sun Aug 7 13:12:29 2022] br_nf_hook_thresh+0x227/0x380 [br_netfilter] [Sun Aug 7 13:12:29 2022] ? setup_pre_routing+0x460/0x460 [br_netfilter] [Sun Aug 7 13:12:29 2022] ? br_handle_local_finish+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? br_nf_pre_routing_ipv6+0x48b/0x69c [br_netfilter] [Sun Aug 7 13:12:29 2022] br_nf_pre_routing_finish_ipv6+0x5c2/0xbf0 [br_netfilter] [Sun Aug 7 13:12:29 2022] ? br_handle_local_finish+0x20/0x20 [Sun Aug 7 13:12:29 2022] br_nf_pre_routing_ipv6+0x4c6/0x69c [br_netfilter] [Sun Aug 7 13:12:29 2022] ? br_validate_ipv6+0x9e0/0x9e0 [br_netfilter] [Sun Aug 7 13:12:29 2022] ? br_nf_forward_arp+0xb70/0xb70 [br_netfilter] [Sun Aug 7 13:12:29 2022] ? br_nf_pre_routing+0xacf/0x1160 [br_netfilter] [Sun Aug 7 13:12:29 2022] br_handle_frame+0x8a9/0x1270 [Sun Aug 7 13:12:29 2022] ? br_handle_frame_finish+0x18e0/0x18e0 [Sun Aug 7 13:12:29 2022] ? register_lock_class+0x1880/0x1880 [Sun Aug 7 13:12:29 2022] ? br_handle_local_finish+0x20/0x20 [Sun Aug 7 13:12:29 2022] ? bond_handle_frame+0xf9/0xac0 [bonding] [Sun Aug 7 13:12:29 2022] ? br_handle_frame_finish+0x18e0/0x18e0 [Sun Aug 7 13:12:29 2022] __netif_receive_skb_core+0x7c0/0x2c70 [Sun Aug 7 13:12:29 2022] ? check_chain_key+0x24a/0x580 [Sun Aug 7 13:12:29 2022] ? generic_xdp_tx+0x5b0/0x5b0 [Sun Aug 7 13:12:29 2022] ? __lock_acquire+0xd6f/0x6720 [Sun Aug 7 13:12:29 2022] ? register_lock_class+0x1880/0x1880 [Sun Aug 7 13:12:29 2022] ? check_chain_key+0x24a/0x580 [Sun Aug 7 13:12:29 2022] __netif_receive_skb_list_core+0x2d7/0x8a0 [Sun Aug 7 13:12:29 2022] ? lock_acquire+0x1c1/0x550 [Sun Aug 7 13:12:29 2022] ? process_backlog+0x960/0x960 [Sun Aug 7 13:12:29 2022] ? lockdep_hardirqs_on_prepare+0x129/0x400 [Sun Aug 7 13:12:29 2022] ? kvm_clock_get_cycles+0x14/0x20 [Sun Aug 7 13:12:29 2022] netif_receive_skb_list_internal+0x5f4/0xd60 [Sun Aug 7 13:12:29 2022] ? do_xdp_generic+0x150/0x150 [Sun Aug 7 13:12:29 2022] ? mlx5e_poll_rx_cq+0xf6b/0x2960 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? mlx5e_poll_ico_cq+0x3d/0x1590 [mlx5_core] [Sun Aug 7 13:12:29 2022] napi_complete_done+0x188/0x710 [Sun Aug 7 13:12:29 2022] mlx5e_napi_poll+0x4e9/0x20a0 [mlx5_core] [Sun Aug 7 13:12:29 2022] ? __queue_work+0x53c/0xeb0 [Sun Aug 7 13:12:29 2022] __napi_poll+0x9f/0x540 [Sun Aug 7 13:12:29 2022] net_rx_action+0x420/0xb70 [Sun Aug 7 13:12:29 2022] ? napi_threaded_poll+0x470/0x470 [Sun Aug 7 13:12:29 2022] ? __common_interrupt+0x79/0x1a0 [Sun Aug 7 13:12:29 2022] __do_softirq+0x271/0x92c [Sun Aug 7 13:12:29 2022] irq_exit_rcu+0x11a/0x170 [Sun Aug 7 13:12:29 2022] common_interrupt+0x7d/0xa0 [Sun Aug 7 13:12:29 2022] </IRQ> [Sun Aug 7 13:12:29 2022] <TASK> [Sun Aug 7 13:12:29 2022] asm_common_interrupt+0x22/0x40 [Sun Aug 7 13:12:29 2022] RIP: 0010:default_idle+0x42/0x60 [Sun Aug 7 13:12:29 2022] Code: c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 04 84 d2 75 14 8b 05 6b f1 22 02 85 c0 7e 07 0f 00 2d 80 3b 4a 00 fb f4 <c3> 48 c7 c7 e0 07 7e 85 e8 21 bd 40 fe eb de 66 66 2e 0f 1f 84 00 [Sun Aug 7 13:12:29 2022] RSP: 0018:ffffffff84407e18 EFLAGS: 00000242 [Sun Aug 7 13:12:29 2022] RAX: 0000000000000001 RBX: ffffffff84ec4a68 RCX: 1ffffffff0afc0fc [Sun Aug 7 13:12:29 2022] RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffffffff835b1fac [Sun Aug 7 13:12:29 2022] RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8884d2c44ac3 [Sun Aug 7 13:12:29 2022] R10: ffffed109a588958 R11: 00000000ffffffff R12: 0000000000000000 [Sun Aug 7 13:12:29 2022] R13: ffffffff84efac20 R14: 0000000000000000 R15: dffffc0000000000 [Sun Aug 7 13:12:29 2022] ? default_idle_call+0xcc/0x460 [Sun Aug 7 13:12:29 2022] default_idle_call+0xec/0x460 [Sun Aug 7 13:12:29 2022] do_idle+0x394/0x450 [Sun Aug 7 13:12:29 2022] ? arch_cpu_idle_exit+0x40/0x40 [Sun Aug 7 13:12:29 2022] cpu_startup_entry+0x19/0x20 [Sun Aug 7 13:12:29 2022] rest_init+0x156/0x250 [Sun Aug 7 13:12:29 2022] arch_call_rest_init+0xf/0x15 [Sun Aug 7 13:12:29 2022] start_kernel+0x3a7/0x3c5 [Sun Aug 7 13:12:29 2022] secondary_startup_64_no_verify+0xcd/0xdb [Sun Aug 7 13:12:29 2022] </TASK> Fixes: ff9b752 ("net/mlx5: Bridge, support LAG") Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Reviewed-by: Mark Bloch <mbloch@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Add a lock_class_key per mlx5 device to avoid a false positive "possible circular locking dependency" warning by lockdep, on flows which lock more than one mlx5 device, such as adding SF. kernel log: ====================================================== WARNING: possible circular locking dependency detected 5.19.0-rc8+ #2 Not tainted ------------------------------------------------------ kworker/u20:0/8 is trying to acquire lock: ffff88812dfe0d98 (&dev->intf_state_mutex){+.+.}-{3:3}, at: mlx5_init_one+0x2e/0x490 [mlx5_core] but task is already holding lock: ffff888101aa7898 (&(¬ifier->n_head)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5a/0x130 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(¬ifier->n_head)->rwsem){++++}-{3:3}: down_write+0x90/0x150 blocking_notifier_chain_register+0x53/0xa0 mlx5_sf_table_init+0x369/0x4a0 [mlx5_core] mlx5_init_one+0x261/0x490 [mlx5_core] probe_one+0x430/0x680 [mlx5_core] local_pci_probe+0xd6/0x170 work_for_cpu_fn+0x4e/0xa0 process_one_work+0x7c2/0x1340 worker_thread+0x6f6/0xec0 kthread+0x28f/0x330 ret_from_fork+0x1f/0x30 -> #0 (&dev->intf_state_mutex){+.+.}-{3:3}: __lock_acquire+0x2fc7/0x6720 lock_acquire+0x1c1/0x550 __mutex_lock+0x12c/0x14b0 mlx5_init_one+0x2e/0x490 [mlx5_core] mlx5_sf_dev_probe+0x29c/0x370 [mlx5_core] auxiliary_bus_probe+0x9d/0xe0 really_probe+0x1e0/0xaa0 __driver_probe_device+0x219/0x480 driver_probe_device+0x49/0x130 __device_attach_driver+0x1b8/0x280 bus_for_each_drv+0x123/0x1a0 __device_attach+0x1a3/0x460 bus_probe_device+0x1a2/0x260 device_add+0x9b1/0x1b40 __auxiliary_device_add+0x88/0xc0 mlx5_sf_dev_state_change_handler+0x67e/0x9d0 [mlx5_core] blocking_notifier_call_chain+0xd5/0x130 mlx5_vhca_state_work_handler+0x2b0/0x3f0 [mlx5_core] process_one_work+0x7c2/0x1340 worker_thread+0x59d/0xec0 kthread+0x28f/0x330 ret_from_fork+0x1f/0x30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(¬ifier->n_head)->rwsem); lock(&dev->intf_state_mutex); lock(&(¬ifier->n_head)->rwsem); lock(&dev->intf_state_mutex); *** DEADLOCK *** 4 locks held by kworker/u20:0/8: #0: ffff888150612938 ((wq_completion)mlx5_events){+.+.}-{0:0}, at: process_one_work+0x6e2/0x1340 #1: ffff888100cafdb8 ((work_completion)(&work->work)#3){+.+.}-{0:0}, at: process_one_work+0x70f/0x1340 #2: ffff888101aa7898 (&(¬ifier->n_head)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5a/0x130 #3: ffff88813682d0e8 (&dev->mutex){....}-{3:3}, at:__device_attach+0x76/0x460 stack backtrace: CPU: 6 PID: 8 Comm: kworker/u20:0 Not tainted 5.19.0-rc8+ Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: mlx5_events mlx5_vhca_state_work_handler [mlx5_core] Call Trace: <TASK> dump_stack_lvl+0x57/0x7d check_noncircular+0x278/0x300 ? print_circular_bug+0x460/0x460 ? lock_chain_count+0x20/0x20 ? register_lock_class+0x1880/0x1880 __lock_acquire+0x2fc7/0x6720 ? register_lock_class+0x1880/0x1880 ? register_lock_class+0x1880/0x1880 lock_acquire+0x1c1/0x550 ? mlx5_init_one+0x2e/0x490 [mlx5_core] ? lockdep_hardirqs_on_prepare+0x400/0x400 __mutex_lock+0x12c/0x14b0 ? mlx5_init_one+0x2e/0x490 [mlx5_core] ? mlx5_init_one+0x2e/0x490 [mlx5_core] ? _raw_read_unlock+0x1f/0x30 ? mutex_lock_io_nested+0x1320/0x1320 ? __ioremap_caller.constprop.0+0x306/0x490 ? mlx5_sf_dev_probe+0x269/0x370 [mlx5_core] ? iounmap+0x160/0x160 mlx5_init_one+0x2e/0x490 [mlx5_core] mlx5_sf_dev_probe+0x29c/0x370 [mlx5_core] ? mlx5_sf_dev_remove+0x130/0x130 [mlx5_core] auxiliary_bus_probe+0x9d/0xe0 really_probe+0x1e0/0xaa0 __driver_probe_device+0x219/0x480 ? auxiliary_match_id+0xe9/0x140 driver_probe_device+0x49/0x130 __device_attach_driver+0x1b8/0x280 ? driver_allows_async_probing+0x140/0x140 bus_for_each_drv+0x123/0x1a0 ? bus_for_each_dev+0x1a0/0x1a0 ? lockdep_hardirqs_on_prepare+0x286/0x400 ? trace_hardirqs_on+0x2d/0x100 __device_attach+0x1a3/0x460 ? device_driver_attach+0x1e0/0x1e0 ? kobject_uevent_env+0x22d/0xf10 bus_probe_device+0x1a2/0x260 device_add+0x9b1/0x1b40 ? dev_set_name+0xab/0xe0 ? __fw_devlink_link_to_suppliers+0x260/0x260 ? memset+0x20/0x40 ? lockdep_init_map_type+0x21a/0x7d0 __auxiliary_device_add+0x88/0xc0 ? auxiliary_device_init+0x86/0xa0 mlx5_sf_dev_state_change_handler+0x67e/0x9d0 [mlx5_core] blocking_notifier_call_chain+0xd5/0x130 mlx5_vhca_state_work_handler+0x2b0/0x3f0 [mlx5_core] ? mlx5_vhca_event_arm+0x100/0x100 [mlx5_core] ? lock_downgrade+0x6e0/0x6e0 ? lockdep_hardirqs_on_prepare+0x286/0x400 process_one_work+0x7c2/0x1340 ? lockdep_hardirqs_on_prepare+0x400/0x400 ? pwq_dec_nr_in_flight+0x230/0x230 ? rwlock_bug.part.0+0x90/0x90 worker_thread+0x59d/0xec0 ? process_one_work+0x1340/0x1340 kthread+0x28f/0x330 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Fixes: 6a32732 ("net/mlx5: SF, Port function state change support") Signed-off-by: Moshe Shemesh <moshe@nvidia.com> Reviewed-by: Shay Drory <shayd@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
A recent commit expanding the scope of the udc_lock mutex in the gadget core managed to cause an obscure and slightly bizarre lockdep violation. In abbreviated form: ====================================================== WARNING: possible circular locking dependency detected 5.19.0-rc7+ #12510 Not tainted ------------------------------------------------------ udevadm/312 is trying to acquire lock: ffff80000aae1058 (udc_lock){+.+.}-{3:3}, at: usb_udc_uevent+0x54/0xe0 but task is already holding lock: ffff000002277548 (kn->active#4){++++}-{0:0}, at: kernfs_seq_start+0x34/0xe0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kn->active#4){++++}-{0:0}: lock_acquire+0x68/0x84 __kernfs_remove+0x268/0x380 kernfs_remove_by_name_ns+0x58/0xac sysfs_remove_file_ns+0x18/0x24 device_del+0x15c/0x440 -> #2 (device_links_lock){+.+.}-{3:3}: lock_acquire+0x68/0x84 __mutex_lock+0x9c/0x430 mutex_lock_nested+0x38/0x64 device_link_remove+0x3c/0xa0 _regulator_put.part.0+0x168/0x190 regulator_put+0x3c/0x54 devm_regulator_release+0x14/0x20 -> #1 (regulator_list_mutex){+.+.}-{3:3}: lock_acquire+0x68/0x84 __mutex_lock+0x9c/0x430 mutex_lock_nested+0x38/0x64 regulator_lock_dependent+0x54/0x284 regulator_enable+0x34/0x80 phy_power_on+0x24/0x130 __dwc2_lowlevel_hw_enable+0x100/0x130 dwc2_lowlevel_hw_enable+0x18/0x40 dwc2_hsotg_udc_start+0x6c/0x2f0 gadget_bind_driver+0x124/0x1f4 -> #0 (udc_lock){+.+.}-{3:3}: __lock_acquire+0x1298/0x20cc lock_acquire.part.0+0xe0/0x230 lock_acquire+0x68/0x84 __mutex_lock+0x9c/0x430 mutex_lock_nested+0x38/0x64 usb_udc_uevent+0x54/0xe0 Evidently this was caused by the scope of udc_mutex being too large. The mutex is only meant to protect udc->driver along with a few other things. As far as I can tell, there's no reason for the mutex to be held while the gadget core calls a gadget driver's ->bind or ->unbind routine, or while a UDC is being started or stopped. (This accounts for link #1 in the chain above, where the mutex is held while the dwc2_hsotg_udc is started as part of driver probing.) Gadget drivers' ->disconnect callbacks are problematic. Even though usb_gadget_disconnect() will now acquire the udc_mutex, there's a window in usb_gadget_bind_driver() between the times when the mutex is released and the ->bind callback is invoked. If a disconnect occurred during that window, we could call the driver's ->disconnect routine before its ->bind routine. To prevent this from happening, it will be necessary to prevent a UDC from connecting while it has no gadget driver. This should be done already but it doesn't seem to be; currently usb_gadget_connect() has no check for this. Such a check will have to be added later. Some degree of mutual exclusion is required in soft_connect_store(), which can dereference udc->driver at arbitrary times since it is a sysfs callback. The solution here is to acquire the gadget's device lock rather than the udc_mutex. Since the driver core guarantees that the device lock is always held during driver binding and unbinding, this will make the accesses in soft_connect_store() mutually exclusive with any changes to udc->driver. Lastly, it turns out there is one place which should hold the udc_mutex but currently does not: The function_show() routine needs protection while it dereferences udc->driver. The missing lock and unlock calls are added. Link: https://lore.kernel.org/all/b2ba4245-9917-e399-94c8-03a383e7070e@samsung.com/ Fixes: 2191c00 ("USB: gadget: Fix use-after-free Read in usb_udc_uevent()") Cc: Felipe Balbi <balbi@kernel.org> Cc: stable@vger.kernel.org Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YwkfhdxA/I2nOcK7@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Automatic kernel fuzzing revealed a recursive locking violation in usb-storage: ============================================ WARNING: possible recursive locking detected 5.18.0 #3 Not tainted -------------------------------------------- kworker/1:3/1205 is trying to acquire lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 but task is already holding lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 ... stack backtrace: CPU: 1 PID: 1205 Comm: kworker/1:3 Not tainted 5.18.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x152/0x3ca kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5630 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x14f/0x1610 kernel/locking/mutex.c:747 usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 usb_reset_device+0x37d/0x9a0 drivers/usb/core/hub.c:6109 r871xu_dev_remove+0x21a/0x270 drivers/staging/rtl8712/usb_intf.c:622 usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:545 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:537 __device_release_driver drivers/base/dd.c:1222 [inline] device_release_driver_internal+0x1a7/0x2f0 drivers/base/dd.c:1248 usb_driver_release_interface+0x102/0x180 drivers/usb/core/driver.c:627 usb_forced_unbind_intf+0x4d/0xa0 drivers/usb/core/driver.c:1118 usb_reset_device+0x39b/0x9a0 drivers/usb/core/hub.c:6114 This turned out not to be an error in usb-storage but rather a nested device reset attempt. That is, as the rtl8712 driver was being unbound from a composite device in preparation for an unrelated USB reset (that driver does not have pre_reset or post_reset callbacks), its ->remove routine called usb_reset_device() -- thus nesting one reset call within another. Performing a reset as part of disconnect processing is a questionable practice at best. However, the bug report points out that the USB core does not have any protection against nested resets. Adding a reset_in_progress flag and testing it will prevent such errors in the future. Link: https://lore.kernel.org/all/CAB7eexKUpvX-JNiLzhXBDWgfg2T9e9_0Tw4HQ6keN==voRbP0g@mail.gmail.com/ Cc: stable@vger.kernel.org Reported-and-tested-by: Rondreis <linhaoguo86@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YwkflDxvg0KWqyZK@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because rxrpc pretends to be a tunnel on top of a UDP/UDP6 socket, allowing it to siphon off UDP packets early in the handling of received UDP packets thereby avoiding the packet going through the UDP receive queue, it doesn't get ICMP packets through the UDP ->sk_error_report() callback. In fact, it doesn't appear that there's any usable option for getting hold of ICMP packets. Fix this by adding a new UDP encap hook to distribute error messages for UDP tunnels. If the hook is set, then the tunnel driver will be able to see ICMP packets. The hook provides the offset into the packet of the UDP header of the original packet that caused the notification. An alternative would be to call the ->error_handler() hook - but that requires that the skbuff be cloned (as ip_icmp_error() or ipv6_cmp_error() do, though isn't really necessary or desirable in rxrpc's case is we want to parse them there and then, not queue them). Changes ======= ver #3) - Fixed an uninitialised variable. ver #2) - Fixed some missing CONFIG_AF_RXRPC_IPV6 conditionals. Fixes: 5271953 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells <dhowells@redhat.com>
The SRv6 layer allows defining HMAC data that can later be used to sign IPv6 Segment Routing Headers. This configuration is realised via netlink through four attributes: SEG6_ATTR_HMACKEYID, SEG6_ATTR_SECRET, SEG6_ATTR_SECRETLEN and SEG6_ATTR_ALGID. Because the SECRETLEN attribute is decoupled from the actual length of the SECRET attribute, it is possible to provide invalid combinations (e.g., secret = "", secretlen = 64). This case is not checked in the code and with an appropriately crafted netlink message, an out-of-bounds read of up to 64 bytes (max secret length) can occur past the skb end pointer and into skb_shared_info: Breakpoint 1, seg6_genl_sethmac (skb=<optimized out>, info=<optimized out>) at net/ipv6/seg6.c:208 208 memcpy(hinfo->secret, secret, slen); (gdb) bt #0 seg6_genl_sethmac (skb=<optimized out>, info=<optimized out>) at net/ipv6/seg6.c:208 #1 0xffffffff81e012e9 in genl_family_rcv_msg_doit (skb=skb@entry=0xffff88800b1f9f00, nlh=nlh@entry=0xffff88800b1b7600, extack=extack@entry=0xffffc90000ba7af0, ops=ops@entry=0xffffc90000ba7a80, hdrlen=4, net=0xffffffff84237580 <init_net>, family=<optimized out>, family=<optimized out>) at net/netlink/genetlink.c:731 #2 0xffffffff81e01435 in genl_family_rcv_msg (extack=0xffffc90000ba7af0, nlh=0xffff88800b1b7600, skb=0xffff88800b1f9f00, family=0xffffffff82fef6c0 <seg6_genl_family>) at net/netlink/genetlink.c:775 #3 genl_rcv_msg (skb=0xffff88800b1f9f00, nlh=0xffff88800b1b7600, extack=0xffffc90000ba7af0) at net/netlink/genetlink.c:792 #4 0xffffffff81dfffc3 in netlink_rcv_skb (skb=skb@entry=0xffff88800b1f9f00, cb=cb@entry=0xffffffff81e01350 <genl_rcv_msg>) at net/netlink/af_netlink.c:2501 #5 0xffffffff81e00919 in genl_rcv (skb=0xffff88800b1f9f00) at net/netlink/genetlink.c:803 #6 0xffffffff81dff6ae in netlink_unicast_kernel (ssk=0xffff888010eec800, skb=0xffff88800b1f9f00, sk=0xffff888004aed000) at net/netlink/af_netlink.c:1319 #7 netlink_unicast (ssk=ssk@entry=0xffff888010eec800, skb=skb@entry=0xffff88800b1f9f00, portid=portid@entry=0, nonblock=<optimized out>) at net/netlink/af_netlink.c:1345 #8 0xffffffff81dff9a4 in netlink_sendmsg (sock=<optimized out>, msg=0xffffc90000ba7e48, len=<optimized out>) at net/netlink/af_netlink.c:1921 ... (gdb) p/x ((struct sk_buff *)0xffff88800b1f9f00)->head + ((struct sk_buff *)0xffff88800b1f9f00)->end $1 = 0xffff88800b1b76c0 (gdb) p/x secret $2 = 0xffff88800b1b76c0 (gdb) p slen $3 = 64 '@' The OOB data can then be read back from userspace by dumping HMAC state. This commit fixes this by ensuring SECRETLEN cannot exceed the actual length of SECRET. Reported-by: Lucas Leong <wmliang.tw@gmail.com> Tested: verified that EINVAL is correctly returned when secretlen > len(secret) Fixes: 4f4853d ("ipv6: sr: implement API to control SR HMAC structure") Signed-off-by: David Lebrun <dlebrun@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
During stress testing with CONFIG_SMP disabled, KASAN reports as below: ================================================================== BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30 Read of size 8 at addr ffff8881094223f8 by task stress/7789 CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Call Trace: <TASK> .. __mutex_lock+0xe5/0xc30 .. z_erofs_do_read_page+0x8ce/0x1560 .. z_erofs_readahead+0x31c/0x580 .. Freed by task 7787 kasan_save_stack+0x1e/0x40 kasan_set_track+0x20/0x30 kasan_set_free_info+0x20/0x40 __kasan_slab_free+0x10c/0x190 kmem_cache_free+0xed/0x380 rcu_core+0x3d5/0xc90 __do_softirq+0x12d/0x389 Last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0x97/0xb0 call_rcu+0x3d/0x3f0 erofs_shrink_workstation+0x11f/0x210 erofs_shrink_scan+0xdc/0x170 shrink_slab.constprop.0+0x296/0x530 drop_slab+0x1c/0x70 drop_caches_sysctl_handler+0x70/0x80 proc_sys_call_handler+0x20a/0x2f0 vfs_write+0x555/0x6c0 ksys_write+0xbe/0x160 do_syscall_64+0x3b/0x90 The root cause is that erofs_workgroup_unfreeze() doesn't reset to orig_val thus it causes a race that the pcluster reuses unexpectedly before freeing. Since UP platforms are quite rare now, such path becomes unnecessary. Let's drop such specific-designed path directly instead. Fixes: 73f5c66 ("staging: erofs: fix `erofs_workgroup_{try_to_freeze, unfreeze}'") Reviewed-by: Yue Hu <huyue2@coolpad.com> Reviewed-by: Chao Yu <chao@kernel.org> Link: https://lore.kernel.org/r/20220902045710.109530-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Since commit: 47546a1 ("arm64: mm: install KPTI nG mappings with MMU enabled)" ... when building with CONFIG_DEBUG_ATOMIC_SLEEP=y and booting under QEMU TCG with '-cpu max', there's a boot-time splat: | BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 15, name: migration/0 | preempt_count: 1, expected: 0 | RCU nest depth: 0, expected: 0 | no locks held by migration/0/15. | irq event stamp: 28 | hardirqs last enabled at (27): [<ffff8000091ed180>] _raw_spin_unlock_irq+0x3c/0x7c | hardirqs last disabled at (28): [<ffff8000081b8d74>] multi_cpu_stop+0x150/0x18c | softirqs last enabled at (0): [<ffff80000809a314>] copy_process+0x594/0x1964 | softirqs last disabled at (0): [<0000000000000000>] 0x0 | CPU: 0 PID: 15 Comm: migration/0 Not tainted 6.0.0-rc3-00002-g419b42ff7eef #3 | Hardware name: linux,dummy-virt (DT) | Stopper: multi_cpu_stop+0x0/0x18c <- stop_cpus.constprop.0+0xa0/0xfc | Call trace: | dump_backtrace.part.0+0xd0/0xe0 | show_stack+0x1c/0x5c | dump_stack_lvl+0x88/0xb4 | dump_stack+0x1c/0x38 | __might_resched+0x180/0x230 | __might_sleep+0x4c/0xa0 | __mutex_lock+0x5c/0x450 | mutex_lock_nested+0x30/0x40 | create_kpti_ng_temp_pgd+0x4fc/0x6d0 | kpti_install_ng_mappings+0x2b8/0x3b0 | cpu_enable_non_boot_scope_capabilities+0x7c/0xd0 | multi_cpu_stop+0xa0/0x18c | cpu_stopper_thread+0x88/0x11c | smpboot_thread_fn+0x1ec/0x290 | kthread+0x118/0x120 | ret_from_fork+0x10/0x20 Since commit: ee017ee ("arm64/mm: avoid fixmap race condition when create pud mapping") ... once the kernel leave the SYSTEM_BOOTING state, the fixmap pagetable entries are protected by the fixmap_lock mutex. The new KPTI rewrite code uses __create_pgd_mapping() to create a temporary pagetable. This happens in atomic context, after secondary CPUs are brought up and the kernel has left the SYSTEM_BOOTING state. Hence we try to acquire a mutex in atomic context, which is generally unsound (though benign in this case as the mutex should be free and all other CPUs are quiescent). This patch avoids the issue by pulling the mutex out of alloc_init_pud() and calling it at a higher level in the pagetable manipulation code. This allows it to be used without locking where one CPU is known to be in exclusive control of the machine, even after having left the SYSTEM_BOOTING state. Fixes: 47546a1 ("arm64: mm: install KPTI nG mappings with MMU enabled") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220920134731.1625740-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
This attempts to avoid circular locking dependency between sock_lock and hdev_lock: WARNING: possible circular locking dependency detected 6.0.0-rc7-03728-g18dd8ab0a783 #3 Not tainted ------------------------------------------------------ kworker/u3:2/53 is trying to acquire lock: ffff888000254130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at: iso_conn_del+0xbd/0x1d0 but task is already holding lock: ffffffff9f39a080 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_le_cis_estabilished_evt+0x1b5/0x500 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hci_cb_list_lock){+.+.}-{3:3}: __mutex_lock+0x10e/0xfe0 hci_le_remote_feat_complete_evt+0x17f/0x320 hci_event_packet+0x39c/0x7d0 hci_rx_work+0x2bf/0x950 process_one_work+0x569/0x980 worker_thread+0x2a3/0x6f0 kthread+0x153/0x180 ret_from_fork+0x22/0x30 -> #1 (&hdev->lock){+.+.}-{3:3}: __mutex_lock+0x10e/0xfe0 iso_connect_cis+0x6f/0x5a0 iso_sock_connect+0x1af/0x710 __sys_connect+0x17e/0x1b0 __x64_sys_connect+0x37/0x50 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x62/0xcc -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}: __lock_acquire+0x1b51/0x33d0 lock_acquire+0x16f/0x3b0 lock_sock_nested+0x32/0x80 iso_conn_del+0xbd/0x1d0 iso_connect_cfm+0x226/0x680 hci_le_cis_estabilished_evt+0x1ed/0x500 hci_event_packet+0x39c/0x7d0 hci_rx_work+0x2bf/0x950 process_one_work+0x569/0x980 worker_thread+0x2a3/0x6f0 kthread+0x153/0x180 ret_from_fork+0x22/0x30 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_ISO --> &hdev->lock --> hci_cb_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hci_cb_list_lock); lock(&hdev->lock); lock(hci_cb_list_lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO); *** DEADLOCK *** 4 locks held by kworker/u3:2/53: #0: ffff8880021d9130 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x4ad/0x980 #1: ffff888002387de0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x4ad/0x980 #2: ffff888001ac0070 (&hdev->lock){+.+.}-{3:3}, at: hci_le_cis_estabilished_evt+0xc3/0x500 #3: ffffffff9f39a080 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_le_cis_estabilished_evt+0x1b5/0x500 Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
We need to check if we have a OS prefix, otherwise we stumble on a metric segv that I'm now seeing in Arnaldo's tree: $ gdb --args perf stat -M Backend true ... Performance counter stats for 'true': 4,712,355 TOPDOWN.SLOTS # 17.3 % tma_core_bound Program received signal SIGSEGV, Segmentation fault. __strlen_evex () at ../sysdeps/x86_64/multiarch/strlen-evex.S:77 77 ../sysdeps/x86_64/multiarch/strlen-evex.S: No such file or directory. (gdb) bt #0 __strlen_evex () at ../sysdeps/x86_64/multiarch/strlen-evex.S:77 #1 0x00007ffff74749a5 in __GI__IO_fputs (str=0x0, fp=0x7ffff75f5680 <_IO_2_1_stderr_>) #2 0x0000555555779f28 in do_new_line_std (config=0x555555e077c0 <stat_config>, os=0x7fffffffbf10) at util/stat-display.c:356 #3 0x000055555577a081 in print_metric_std (config=0x555555e077c0 <stat_config>, ctx=0x7fffffffbf10, color=0x0, fmt=0x5555558b77b5 "%8.1f", unit=0x7fffffffbb10 "% tma_memory_bound", val=13.165355724442199) at util/stat-display.c:380 #4 0x00005555557768b6 in generic_metric (config=0x555555e077c0 <stat_config>, metric_expr=0x55555593d5b7 "((CYCLE_ACTIVITY.STALLS_MEM_ANY + EXE_ACTIVITY.BOUND_ON_STORES) / (CYCLE_ACTIVITY.STALLS_TOTAL + (EXE_ACTIVITY.1_PORTS_UTIL + tma_retiring * EXE_ACTIVITY.2_PORTS_UTIL) + EXE_ACTIVITY.BOUND_ON_STORES))"..., metric_events=0x555555f334e0, metric_refs=0x555555ec81d0, name=0x555555f32e80 "TOPDOWN.SLOTS", metric_name=0x555555f26c80 "tma_memory_bound", metric_unit=0x55555593d5b1 "100%", runtime=0, map_idx=0, out=0x7fffffffbd90, st=0x555555e9e620 <rt_stat>) at util/stat-shadow.c:934 #5 0x0000555555778cac in perf_stat__print_shadow_stats (config=0x555555e077c0 <stat_config>, evsel=0x555555f289d0, avg=4712355, map_idx=0, out=0x7fffffffbd90, metric_events=0x555555e078e8 <stat_config+296>, st=0x555555e9e620 <rt_stat>) at util/stat-shadow.c:1329 #6 0x000055555577b6a0 in printout (config=0x555555e077c0 <stat_config>, os=0x7fffffffbf10, uval=4712355, run=325322, ena=325322, noise=4712355, map_idx=0) at util/stat-display.c:741 #7 0x000055555577bc74 in print_counter_aggrdata (config=0x555555e077c0 <stat_config>, counter=0x555555f289d0, s=0, os=0x7fffffffbf10) at util/stat-display.c:838 #8 0x000055555577c1d8 in print_counter (config=0x555555e077c0 <stat_config>, counter=0x555555f289d0, os=0x7fffffffbf10) at util/stat-display.c:957 #9 0x000055555577dba0 in evlist__print_counters (evlist=0x555555ec3610, config=0x555555e077c0 <stat_config>, _target=0x555555e01c80 <target>, ts=0x0, argc=1, argv=0x7fffffffe450) at util/stat-display.c:1413 #10 0x00005555555fc821 in print_counters (ts=0x0, argc=1, argv=0x7fffffffe450) at builtin-stat.c:1040 #11 0x000055555560091a in cmd_stat (argc=1, argv=0x7fffffffe450) at builtin-stat.c:2665 #12 0x00005555556b1eea in run_builtin (p=0x555555e11f70 <commands+336>, argc=4, argv=0x7fffffffe450) at perf.c:322 #13 0x00005555556b2181 in handle_internal_command (argc=4, argv=0x7fffffffe450) at perf.c:376 #14 0x00005555556b22d7 in run_argv (argcp=0x7fffffffe27c, argv=0x7fffffffe270) at perf.c:420 #15 0x00005555556b26ef in main (argc=4, argv=0x7fffffffe450) at perf.c:550 (gdb) Fixes: f123b2d ("perf stat: Remove prefix argument in print_metric_headers()") Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com> Link: http://lore.kernel.org/lkml/CAP-5=fUOjSM5HajU9TCD6prY39LbX4OQbkEbtKPPGRBPBN=_VQ@mail.gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The propagate_mnt() function handles mount propagation when creating mounts and propagates the source mount tree @source_mnt to all applicable nodes of the destination propagation mount tree headed by @dest_mnt. Unfortunately it contains a bug where it fails to terminate at peers of @source_mnt when looking up copies of the source mount that become masters for copies of the source mount tree mounted on top of slaves in the destination propagation tree causing a NULL dereference. Once the mechanics of the bug are understood it's easy to trigger. Because of unprivileged user namespaces it is available to unprivileged users. While fixing this bug we've gotten confused multiple times due to unclear terminology or missing concepts. So let's start this with some clarifications: * The terms "master" or "peer" denote a shared mount. A shared mount belongs to a peer group. * A peer group is a set of shared mounts that propagate to each other. They are identified by a peer group id. The peer group id is available in @shared_mnt->mnt_group_id. Shared mounts within the same peer group have the same peer group id. The peers in a peer group can be reached via @shared_mnt->mnt_share. * The terms "slave mount" or "dependent mount" denote a mount that receives propagation from a peer in a peer group. IOW, shared mounts may have slave mounts and slave mounts have shared mounts as their master. Slave mounts of a given peer in a peer group are listed on that peers slave list available at @shared_mnt->mnt_slave_list. * The term "master mount" denotes a mount in a peer group. IOW, it denotes a shared mount or a peer mount in a peer group. The term "master mount" - or "master" for short - is mostly used when talking in the context of slave mounts that receive propagation from a master mount. A master mount of a slave identifies the closest peer group a slave mount receives propagation from. The master mount of a slave can be identified via @slave_mount->mnt_master. Different slaves may point to different masters in the same peer group. * Multiple peers in a peer group can have non-empty ->mnt_slave_lists. Non-empty ->mnt_slave_lists of peers don't intersect. Consequently, to ensure all slave mounts of a peer group are visited the ->mnt_slave_lists of all peers in a peer group have to be walked. * Slave mounts point to a peer in the closest peer group they receive propagation from via @slave_mnt->mnt_master (see above). Together with these peers they form a propagation group (see below). The closest peer group can thus be identified through the peer group id @slave_mnt->mnt_master->mnt_group_id of the peer/master that a slave mount receives propagation from. * A shared-slave mount is a slave mount to a peer group pg1 while also a peer in another peer group pg2. IOW, a peer group may receive propagation from another peer group. If a peer group pg1 is a slave to another peer group pg2 then all peers in peer group pg1 point to the same peer in peer group pg2 via ->mnt_master. IOW, all peers in peer group pg1 appear on the same ->mnt_slave_list. IOW, they cannot be slaves to different peer groups. * A pure slave mount is a slave mount that is a slave to a peer group but is not a peer in another peer group. * A propagation group denotes the set of mounts consisting of a single peer group pg1 and all slave mounts and shared-slave mounts that point to a peer in that peer group via ->mnt_master. IOW, all slave mounts such that @slave_mnt->mnt_master->mnt_group_id is equal to @shared_mnt->mnt_group_id. The concept of a propagation group makes it easier to talk about a single propagation level in a propagation tree. For example, in propagate_mnt() the immediate peers of @dest_mnt and all slaves of @dest_mnt's peer group form a propagation group propg1. So a shared-slave mount that is a slave in propg1 and that is a peer in another peer group pg2 forms another propagation group propg2 together with all slaves that point to that shared-slave mount in their ->mnt_master. * A propagation tree refers to all mounts that receive propagation starting from a specific shared mount. For example, for propagate_mnt() @dest_mnt is the start of a propagation tree. The propagation tree ecompasses all mounts that receive propagation from @dest_mnt's peer group down to the leafs. With that out of the way let's get to the actual algorithm. We know that @dest_mnt is guaranteed to be a pure shared mount or a shared-slave mount. This is guaranteed by a check in attach_recursive_mnt(). So propagate_mnt() will first propagate the source mount tree to all peers in @dest_mnt's peer group: for (n = next_peer(dest_mnt); n != dest_mnt; n = next_peer(n)) { ret = propagate_one(n); if (ret) goto out; } Notice, that the peer propagation loop of propagate_mnt() doesn't propagate @dest_mnt itself. @dest_mnt is mounted directly in attach_recursive_mnt() after we propagated to the destination propagation tree. The mount that will be mounted on top of @dest_mnt is @source_mnt. This copy was created earlier even before we entered attach_recursive_mnt() and doesn't concern us a lot here. It's just important to notice that when propagate_mnt() is called @source_mnt will not yet have been mounted on top of @dest_mnt. Thus, @source_mnt->mnt_parent will either still point to @source_mnt or - in the case @source_mnt is moved and thus already attached - still to its former parent. For each peer @m in @dest_mnt's peer group propagate_one() will create a new copy of the source mount tree and mount that copy @child on @m such that @child->mnt_parent points to @m after propagate_one() returns. propagate_one() will stash the last destination propagation node @m in @last_dest and the last copy it created for the source mount tree in @last_source. Hence, if we call into propagate_one() again for the next destination propagation node @m, @last_dest will point to the previous destination propagation node and @last_source will point to the previous copy of the source mount tree and mounted on @last_dest. Each new copy of the source mount tree is created from the previous copy of the source mount tree. This will become important later. The peer loop in propagate_mnt() is straightforward. We iterate through the peers copying and updating @last_source and @last_dest as we go through them and mount each copy of the source mount tree @child on a peer @m in @dest_mnt's peer group. After propagate_mnt() handled the peers in @dest_mnt's peer group propagate_mnt() will propagate the source mount tree down the propagation tree that @dest_mnt's peer group propagates to: for (m = next_group(dest_mnt, dest_mnt); m; m = next_group(m, dest_mnt)) { /* everything in that slave group */ n = m; do { ret = propagate_one(n); if (ret) goto out; n = next_peer(n); } while (n != m); } The next_group() helper will recursively walk the destination propagation tree, descending into each propagation group of the propagation tree. The important part is that it takes care to propagate the source mount tree to all peers in the peer group of a propagation group before it propagates to the slaves to those peers in the propagation group. IOW, it creates and mounts copies of the source mount tree that become masters before it creates and mounts copies of the source mount tree that become slaves to these masters. It is important to remember that propagating the source mount tree to each mount @m in the destination propagation tree simply means that we create and mount new copies @child of the source mount tree on @m such that @child->mnt_parent points to @m. Since we know that each node @m in the destination propagation tree headed by @dest_mnt's peer group will be overmounted with a copy of the source mount tree and since we know that the propagation properties of each copy of the source mount tree we create and mount at @m will mostly mirror the propagation properties of @m. We can use that information to create and mount the copies of the source mount tree that become masters before their slaves. The easy case is always when @m and @last_dest are peers in a peer group of a given propagation group. In that case we know that we can simply copy @last_source without having to figure out what the master for the new copy @child of the source mount tree needs to be as we've done that in a previous call to propagate_one(). The hard case is when we're dealing with a slave mount or a shared-slave mount @m in a destination propagation group that we need to create and mount a copy of the source mount tree on. For each propagation group in the destination propagation tree we propagate the source mount tree to we want to make sure that the copies @child of the source mount tree we create and mount on slaves @m pick an ealier copy of the source mount tree that we mounted on a master @m of the destination propagation group as their master. This is a mouthful but as far as we can tell that's the core of it all. But, if we keep track of the masters in the destination propagation tree @m we can use the information to find the correct master for each copy of the source mount tree we create and mount at the slaves in the destination propagation tree @m. Let's walk through the base case as that's still fairly easy to grasp. If we're dealing with the first slave in the propagation group that @dest_mnt is in then we don't yet have marked any masters in the destination propagation tree. We know the master for the first slave to @dest_mnt's peer group is simple @dest_mnt. So we expect this algorithm to yield a copy of the source mount tree that was mounted on a peer in @dest_mnt's peer group as the master for the copy of the source mount tree we want to mount at the first slave @m: for (n = m; ; n = p) { p = n->mnt_master; if (p == dest_master || IS_MNT_MARKED(p)) break; } For the first slave we walk the destination propagation tree all the way up to a peer in @dest_mnt's peer group. IOW, the propagation hierarchy can be walked by walking up the @mnt->mnt_master hierarchy of the destination propagation tree @m. We will ultimately find a peer in @dest_mnt's peer group and thus ultimately @dest_mnt->mnt_master. Btw, here the assumption we listed at the beginning becomes important. Namely, that peers in a peer group pg1 that are slaves in another peer group pg2 appear on the same ->mnt_slave_list. IOW, all slaves who are peers in peer group pg1 point to the same peer in peer group pg2 via their ->mnt_master. Otherwise the termination condition in the code above would be wrong and next_group() would be broken too. So the first iteration sets: n = m; p = n->mnt_master; such that @p now points to a peer or @dest_mnt itself. We walk up one more level since we don't have any marked mounts. So we end up with: n = dest_mnt; p = dest_mnt->mnt_master; If @dest_mnt's peer group is not slave to another peer group then @p is now NULL. If @dest_mnt's peer group is a slave to another peer group then @p now points to @dest_mnt->mnt_master points which is a master outside the propagation tree we're dealing with. Now we need to figure out the master for the copy of the source mount tree we're about to create and mount on the first slave of @dest_mnt's peer group: do { struct mount *parent = last_source->mnt_parent; if (last_source == first_source) break; done = parent->mnt_master == p; if (done && peers(n, parent)) break; last_source = last_source->mnt_master; } while (!done); We know that @last_source->mnt_parent points to @last_dest and @last_dest is the last peer in @dest_mnt's peer group we propagated to in the peer loop in propagate_mnt(). Consequently, @last_source is the last copy we created and mount on that last peer in @dest_mnt's peer group. So @last_source is the master we want to pick. We know that @last_source->mnt_parent->mnt_master points to @last_dest->mnt_master. We also know that @last_dest->mnt_master is either NULL or points to a master outside of the destination propagation tree and so does @p. Hence: done = parent->mnt_master == p; is trivially true in the base condition. We also know that for the first slave mount of @dest_mnt's peer group that @last_dest either points @dest_mnt itself because it was initialized to: last_dest = dest_mnt; at the beginning of propagate_mnt() or it will point to a peer of @dest_mnt in its peer group. In both cases it is guaranteed that on the first iteration @n and @parent are peers (Please note the check for peers here as that's important.): if (done && peers(n, parent)) break; So, as we expected, we select @last_source, which referes to the last copy of the source mount tree we mounted on the last peer in @dest_mnt's peer group, as the master of the first slave in @dest_mnt's peer group. The rest is taken care of by clone_mnt(last_source, ...). We'll skip over that part otherwise this becomes a blogpost. At the end of propagate_mnt() we now mark @m->mnt_master as the first master in the destination propagation tree that is distinct from @dest_mnt->mnt_master. IOW, we mark @dest_mnt itself as a master. By marking @dest_mnt or one of it's peers we are able to easily find it again when we later lookup masters for other copies of the source mount tree we mount copies of the source mount tree on slaves @m to @dest_mnt's peer group. This, in turn allows us to find the master we selected for the copies of the source mount tree we mounted on master in the destination propagation tree again. The important part is to realize that the code makes use of the fact that the last copy of the source mount tree stashed in @last_source was mounted on top of the previous destination propagation node @last_dest. What this means is that @last_source allows us to walk the destination propagation hierarchy the same way each destination propagation node @m does. If we take @last_source, which is the copy of @source_mnt we have mounted on @last_dest in the previous iteration of propagate_one(), then we know @last_source->mnt_parent points to @last_dest but we also know that as we walk through the destination propagation tree that @last_source->mnt_master will point to an earlier copy of the source mount tree we mounted one an earlier destination propagation node @m. IOW, @last_source->mnt_parent will be our hook into the destination propagation tree and each consecutive @last_source->mnt_master will lead us to an earlier propagation node @m via @last_source->mnt_master->mnt_parent. Hence, by walking up @last_source->mnt_master, each of which is mounted on a node that is a master @m in the destination propagation tree we can also walk up the destination propagation hierarchy. So, for each new destination propagation node @m we use the previous copy of @last_source and the fact it's mounted on the previous propagation node @last_dest via @last_source->mnt_master->mnt_parent to determine what the master of the new copy of @last_source needs to be. The goal is to find the _closest_ master that the new copy of the source mount tree we are about to create and mount on a slave @m in the destination propagation tree needs to pick. IOW, we want to find a suitable master in the propagation group. As the propagation structure of the source mount propagation tree we create mirrors the propagation structure of the destination propagation tree we can find @m's closest master - i.e., a marked master - which is a peer in the closest peer group that @m receives propagation from. We store that closest master of @m in @p as before and record the slave to that master in @n We then search for this master @p via @last_source by walking up the master hierarchy starting from the last copy of the source mount tree stored in @last_source that we created and mounted on the previous destination propagation node @m. We will try to find the master by walking @last_source->mnt_master and by comparing @last_source->mnt_master->mnt_parent->mnt_master to @p. If we find @p then we can figure out what earlier copy of the source mount tree needs to be the master for the new copy of the source mount tree we're about to create and mount at the current destination propagation node @m. If @last_source->mnt_master->mnt_parent and @n are peers then we know that the closest master they receive propagation from is @last_source->mnt_master->mnt_parent->mnt_master. If not then the closest immediate peer group that they receive propagation from must be one level higher up. This builds on the earlier clarification at the beginning that all peers in a peer group which are slaves of other peer groups all point to the same ->mnt_master, i.e., appear on the same ->mnt_slave_list, of the closest peer group that they receive propagation from. However, terminating the walk has corner cases. If the closest marked master for a given destination node @m cannot be found by walking up the master hierarchy via @last_source->mnt_master then we need to terminate the walk when we encounter @source_mnt again. This isn't an arbitrary termination. It simply means that the new copy of the source mount tree we're about to create has a copy of the source mount tree we created and mounted on a peer in @dest_mnt's peer group as its master. IOW, @source_mnt is the peer in the closest peer group that the new copy of the source mount tree receives propagation from. We absolutely have to stop @source_mnt because @last_source->mnt_master either points outside the propagation hierarchy we're dealing with or it is NULL because @source_mnt isn't a shared-slave. So continuing the walk past @source_mnt would cause a NULL dereference via @last_source->mnt_master->mnt_parent. And so we have to stop the walk when we encounter @source_mnt again. One scenario where this can happen is when we first handled a series of slaves of @dest_mnt's peer group and then encounter peers in a new peer group that is a slave to @dest_mnt's peer group. We handle them and then we encounter another slave mount to @dest_mnt that is a pure slave to @dest_mnt's peer group. That pure slave will have a peer in @dest_mnt's peer group as its master. Consequently, the new copy of the source mount tree will need to have @source_mnt as it's master. So we walk the propagation hierarchy all the way up to @source_mnt based on @last_source->mnt_master. So terminate on @source_mnt, easy peasy. Except, that the check misses something that the rest of the algorithm already handles. If @dest_mnt has peers in it's peer group the peer loop in propagate_mnt(): for (n = next_peer(dest_mnt); n != dest_mnt; n = next_peer(n)) { ret = propagate_one(n); if (ret) goto out; } will consecutively update @last_source with each previous copy of the source mount tree we created and mounted at the previous peer in @dest_mnt's peer group. So after that loop terminates @last_source will point to whatever copy of the source mount tree was created and mounted on the last peer in @dest_mnt's peer group. Furthermore, if there is even a single additional peer in @dest_mnt's peer group then @last_source will __not__ point to @source_mnt anymore. Because, as we mentioned above, @dest_mnt isn't even handled in this loop but directly in attach_recursive_mnt(). So it can't even accidently come last in that peer loop. So the first time we handle a slave mount @m of @dest_mnt's peer group the copy of the source mount tree we create will make the __last copy of the source mount tree we created and mounted on the last peer in @dest_mnt's peer group the master of the new copy of the source mount tree we create and mount on the first slave of @dest_mnt's peer group__. But this means that the termination condition that checks for @source_mnt is wrong. The @source_mnt cannot be found anymore by propagate_one(). Instead it will find the last copy of the source mount tree we created and mounted for the last peer of @dest_mnt's peer group again. And that is a peer of @source_mnt not @source_mnt itself. IOW, we fail to terminate the loop correctly and ultimately dereference @last_source->mnt_master->mnt_parent. When @source_mnt's peer group isn't slave to another peer group then @last_source->mnt_master is NULL causing the splat below. For example, assume @dest_mnt is a pure shared mount and has three peers in its peer group: =================================================================================== mount-id mount-parent-id peer-group-id =================================================================================== (@dest_mnt) mnt_master[216] 309 297 shared:216 \ (@source_mnt) mnt_master[218]: 609 609 shared:218 (1) mnt_master[216]: 607 605 shared:216 \ (P1) mnt_master[218]: 624 607 shared:218 (2) mnt_master[216]: 576 574 shared:216 \ (P2) mnt_master[218]: 625 576 shared:218 (3) mnt_master[216]: 545 543 shared:216 \ (P3) mnt_master[218]: 626 545 shared:218 After this sequence has been processed @last_source will point to (P3), the copy generated for the third peer in @dest_mnt's peer group we handled. So the copy of the source mount tree (P4) we create and mount on the first slave of @dest_mnt's peer group: =================================================================================== mount-id mount-parent-id peer-group-id =================================================================================== mnt_master[216] 309 297 shared:216 / / (S0) mnt_slave 483 481 master:216 \ \ (P3) mnt_master[218] 626 545 shared:218 \ / \/ (P4) mnt_slave 627 483 master:218 will pick the last copy of the source mount tree (P3) as master, not (S0). When walking the propagation hierarchy via @last_source's master hierarchy we encounter (P3) but not (S0), i.e., @source_mnt. We can fix this in multiple ways: (1) By setting @last_source to @source_mnt after we processed the peers in @dest_mnt's peer group right after the peer loop in propagate_mnt(). (2) By changing the termination condition that relies on finding exactly @source_mnt to finding a peer of @source_mnt. (3) By only moving @last_source when we actually venture into a new peer group or some clever variant thereof. The first two options are minimally invasive and what we want as a fix. The third option is more intrusive but something we'd like to explore in the near future. This passes all LTP tests and specifically the mount propagation testsuite part of it. It also holds up against all known reproducers of this issues. Final words. First, this is a clever but __worringly__ underdocumented algorithm. There isn't a single detailed comment to be found in next_group(), propagate_one() or anywhere else in that file for that matter. This has been a giant pain to understand and work through and a bug like this is insanely difficult to fix without a detailed understanding of what's happening. Let's not talk about the amount of time that was sunk into fixing this. Second, all the cool kids with access to unshare --mount --user --map-root --propagation=unchanged are going to have a lot of fun. IOW, triggerable by unprivileged users while namespace_lock() lock is held. [ 115.848393] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 115.848967] #PF: supervisor read access in kernel mode [ 115.849386] #PF: error_code(0x0000) - not-present page [ 115.849803] PGD 0 P4D 0 [ 115.850012] Oops: 0000 [#1] PREEMPT SMP PTI [ 115.850354] CPU: 0 PID: 15591 Comm: mount Not tainted 6.1.0-rc7 #3 [ 115.850851] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 115.851510] RIP: 0010:propagate_one.part.0+0x7f/0x1a0 [ 115.851924] Code: 75 eb 4c 8b 05 c2 25 37 02 4c 89 ca 48 8b 4a 10 49 39 d0 74 1e 48 3b 81 e0 00 00 00 74 26 48 8b 92 e0 00 00 00 be 01 00 00 00 <48> 8b 4a 10 49 39 d0 75 e2 40 84 f6 74 38 4c 89 05 84 25 37 02 4d [ 115.853441] RSP: 0018:ffffb8d5443d7d50 EFLAGS: 00010282 [ 115.853865] RAX: ffff8e4d87c41c80 RBX: ffff8e4d88ded780 RCX: ffff8e4da4333a00 [ 115.854458] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8e4d88ded780 [ 115.855044] RBP: ffff8e4d88ded780 R08: ffff8e4da4338000 R09: ffff8e4da43388c0 [ 115.855693] R10: 0000000000000002 R11: ffffb8d540158000 R12: ffffb8d5443d7da8 [ 115.856304] R13: ffff8e4d88ded780 R14: 0000000000000000 R15: 0000000000000000 [ 115.856859] FS: 00007f92c90c9800(0000) GS:ffff8e4dfdc00000(0000) knlGS:0000000000000000 [ 115.857531] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 115.858006] CR2: 0000000000000010 CR3: 0000000022f4c002 CR4: 00000000000706f0 [ 115.858598] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 115.859393] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 115.860099] Call Trace: [ 115.860358] <TASK> [ 115.860535] propagate_mnt+0x14d/0x190 [ 115.860848] attach_recursive_mnt+0x274/0x3e0 [ 115.861212] path_mount+0x8c8/0xa60 [ 115.861503] __x64_sys_mount+0xf6/0x140 [ 115.861819] do_syscall_64+0x5b/0x80 [ 115.862117] ? do_faccessat+0x123/0x250 [ 115.862435] ? syscall_exit_to_user_mode+0x17/0x40 [ 115.862826] ? do_syscall_64+0x67/0x80 [ 115.863133] ? syscall_exit_to_user_mode+0x17/0x40 [ 115.863527] ? do_syscall_64+0x67/0x80 [ 115.863835] ? do_syscall_64+0x67/0x80 [ 115.864144] ? do_syscall_64+0x67/0x80 [ 115.864452] ? exc_page_fault+0x70/0x170 [ 115.864775] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 115.865187] RIP: 0033:0x7f92c92b0ebe [ 115.865480] Code: 48 8b 0d 75 4f 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 42 4f 0c 00 f7 d8 64 89 01 48 [ 115.866984] RSP: 002b:00007fff000aa728 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 115.867607] RAX: ffffffffffffffda RBX: 000055a77888d6b0 RCX: 00007f92c92b0ebe [ 115.868240] RDX: 000055a77888d8e0 RSI: 000055a77888e6e0 RDI: 000055a77888e620 [ 115.868823] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 115.869403] R10: 0000000000001000 R11: 0000000000000246 R12: 000055a77888e620 [ 115.869994] R13: 000055a77888d8e0 R14: 00000000ffffffff R15: 00007f92c93e4076 [ 115.870581] </TASK> [ 115.870763] Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set rfkill nf_tables nfnetlink qrtr snd_intel8x0 sunrpc snd_ac97_codec ac97_bus snd_pcm snd_timer intel_rapl_msr intel_rapl_common snd vboxguest intel_powerclamp video rapl joydev soundcore i2c_piix4 wmi fuse zram xfs vmwgfx crct10dif_pclmul crc32_pclmul crc32c_intel polyval_clmulni polyval_generic drm_ttm_helper ttm e1000 ghash_clmulni_intel serio_raw ata_generic pata_acpi scsi_dh_rdac scsi_dh_emc scsi_dh_alua dm_multipath [ 115.875288] CR2: 0000000000000010 [ 115.875641] ---[ end trace 0000000000000000 ]--- [ 115.876135] RIP: 0010:propagate_one.part.0+0x7f/0x1a0 [ 115.876551] Code: 75 eb 4c 8b 05 c2 25 37 02 4c 89 ca 48 8b 4a 10 49 39 d0 74 1e 48 3b 81 e0 00 00 00 74 26 48 8b 92 e0 00 00 00 be 01 00 00 00 <48> 8b 4a 10 49 39 d0 75 e2 40 84 f6 74 38 4c 89 05 84 25 37 02 4d [ 115.878086] RSP: 0018:ffffb8d5443d7d50 EFLAGS: 00010282 [ 115.878511] RAX: ffff8e4d87c41c80 RBX: ffff8e4d88ded780 RCX: ffff8e4da4333a00 [ 115.879128] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8e4d88ded780 [ 115.879715] RBP: ffff8e4d88ded780 R08: ffff8e4da4338000 R09: ffff8e4da43388c0 [ 115.880359] R10: 0000000000000002 R11: ffffb8d540158000 R12: ffffb8d5443d7da8 [ 115.880962] R13: ffff8e4d88ded780 R14: 0000000000000000 R15: 0000000000000000 [ 115.881548] FS: 00007f92c90c9800(0000) GS:ffff8e4dfdc00000(0000) knlGS:0000000000000000 [ 115.882234] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 115.882713] CR2: 0000000000000010 CR3: 0000000022f4c002 CR4: 00000000000706f0 [ 115.883314] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 115.883966] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: f2ebb3a ("smarter propagate_mnt()") Fixes: 5ec0811 ("propogate_mnt: Handle the first propogated copy being a slave") Cc: <stable@vger.kernel.org> Reported-by: Ditang Chen <ditang.c@gmail.com> Signed-off-by: Seth Forshee (Digital Ocean) <sforshee@kernel.org> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> --- If there are no big objections I'll get this to Linus rather sooner than later.
When doing timestamping in lan966x and having PROVE_LOCKING enabled the following warning is shown. ======================================================== WARNING: possible irq lock inversion dependency detected 6.2.0-rc7-01749-gc54e1f7f7e36 #2786 Tainted: G N -------------------------------------------------------- swapper/0/0 just changed the state of lock: c2609f50 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x16c/0x2e8 but this lock took another, SOFTIRQ-unsafe lock in the past: (&lan966x->ptp_ts_id_lock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lan966x->ptp_ts_id_lock); local_irq_disable(); lock(_xmit_ETHER#2); lock(&lan966x->ptp_ts_id_lock); <Interrupt> lock(_xmit_ETHER#2); *** DEADLOCK *** 5 locks held by swapper/0/0: #0: c1001e18 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0x0/0x33c #1: c105e7c4 (rcu_read_lock){....}-{1:2}, at: ndisc_send_skb+0x134/0x81c #2: c105e7d8 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x17c/0xc64 #3: c105e7d8 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x4c/0x1224 #4: c3056174 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x354/0x1224 the shortest dependencies between 2nd lock and 1st lock: -> (&lan966x->ptp_ts_id_lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire.part.0+0xb0/0x248 _raw_spin_lock+0x38/0x48 lan966x_ptp_irq_handler+0x164/0x2a8 irq_thread_fn+0x1c/0x78 irq_thread+0x130/0x278 kthread+0xec/0x110 ret_from_fork+0x14/0x28 SOFTIRQ-ON-W at: lock_acquire.part.0+0xb0/0x248 _raw_spin_lock+0x38/0x48 lan966x_ptp_irq_handler+0x164/0x2a8 irq_thread_fn+0x1c/0x78 irq_thread+0x130/0x278 kthread+0xec/0x110 ret_from_fork+0x14/0x28 INITIAL USE at: lock_acquire.part.0+0xb0/0x248 _raw_spin_lock_irqsave+0x4c/0x68 lan966x_ptp_txtstamp_request+0x128/0x1cc lan966x_port_xmit+0x224/0x43c dev_hard_start_xmit+0xa8/0x2f0 sch_direct_xmit+0x108/0x2e8 __dev_queue_xmit+0x41c/0x1224 packet_sendmsg+0xdb4/0x134c __sys_sendto+0xd0/0x154 sys_send+0x18/0x20 ret_fast_syscall+0x0/0x1c } ... key at: [<c174ba0c>] __key.2+0x0/0x8 ... acquired at: _raw_spin_lock_irqsave+0x4c/0x68 lan966x_ptp_txtstamp_request+0x128/0x1cc lan966x_port_xmit+0x224/0x43c dev_hard_start_xmit+0xa8/0x2f0 sch_direct_xmit+0x108/0x2e8 __dev_queue_xmit+0x41c/0x1224 packet_sendmsg+0xdb4/0x134c __sys_sendto+0xd0/0x154 sys_send+0x18/0x20 ret_fast_syscall+0x0/0x1c -> (_xmit_ETHER#2){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire.part.0+0xb0/0x248 _raw_spin_lock+0x38/0x48 netif_freeze_queues+0x38/0x68 dev_deactivate_many+0xac/0x388 dev_deactivate+0x38/0x6c linkwatch_do_dev+0x70/0x8c __linkwatch_run_queue+0xd4/0x1e8 linkwatch_event+0x24/0x34 process_one_work+0x284/0x744 worker_thread+0x28/0x4bc kthread+0xec/0x110 ret_from_fork+0x14/0x28 IN-SOFTIRQ-W at: lock_acquire.part.0+0xb0/0x248 _raw_spin_lock+0x38/0x48 sch_direct_xmit+0x16c/0x2e8 __dev_queue_xmit+0x41c/0x1224 ip6_finish_output2+0x5f4/0xc64 ndisc_send_skb+0x4cc/0x81c addrconf_rs_timer+0xb0/0x2f8 call_timer_fn+0xb4/0x33c expire_timers+0xb4/0x10c run_timer_softirq+0xf8/0x2a8 __do_softirq+0xd4/0x5fc __irq_exit_rcu+0x138/0x17c irq_exit+0x8/0x28 __irq_svc+0x90/0xbc arch_cpu_idle+0x30/0x3c default_idle_call+0x44/0xac do_idle+0xc8/0x138 cpu_startup_entry+0x18/0x1c rest_init+0xcc/0x168 arch_post_acpi_subsys_init+0x0/0x8 INITIAL USE at: lock_acquire.part.0+0xb0/0x248 _raw_spin_lock+0x38/0x48 netif_freeze_queues+0x38/0x68 dev_deactivate_many+0xac/0x388 dev_deactivate+0x38/0x6c linkwatch_do_dev+0x70/0x8c __linkwatch_run_queue+0xd4/0x1e8 linkwatch_event+0x24/0x34 process_one_work+0x284/0x744 worker_thread+0x28/0x4bc kthread+0xec/0x110 ret_from_fork+0x14/0x28 } ... key at: [<c175974c>] netdev_xmit_lock_key+0x8/0x1c8 ... acquired at: __lock_acquire+0x978/0x2978 lock_acquire.part.0+0xb0/0x248 _raw_spin_lock+0x38/0x48 sch_direct_xmit+0x16c/0x2e8 __dev_queue_xmit+0x41c/0x1224 ip6_finish_output2+0x5f4/0xc64 ndisc_send_skb+0x4cc/0x81c addrconf_rs_timer+0xb0/0x2f8 call_timer_fn+0xb4/0x33c expire_timers+0xb4/0x10c run_timer_softirq+0xf8/0x2a8 __do_softirq+0xd4/0x5fc __irq_exit_rcu+0x138/0x17c irq_exit+0x8/0x28 __irq_svc+0x90/0xbc arch_cpu_idle+0x30/0x3c default_idle_call+0x44/0xac do_idle+0xc8/0x138 cpu_startup_entry+0x18/0x1c rest_init+0xcc/0x168 arch_post_acpi_subsys_init+0x0/0x8 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G N 6.2.0-rc7-01749-gc54e1f7f7e36 #2786 Hardware name: Generic DT based system unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x58/0x70 dump_stack_lvl from mark_lock.part.0+0x59c/0x93c mark_lock.part.0 from __lock_acquire+0x978/0x2978 __lock_acquire from lock_acquire.part.0+0xb0/0x248 lock_acquire.part.0 from _raw_spin_lock+0x38/0x48 _raw_spin_lock from sch_direct_xmit+0x16c/0x2e8 sch_direct_xmit from __dev_queue_xmit+0x41c/0x1224 __dev_queue_xmit from ip6_finish_output2+0x5f4/0xc64 ip6_finish_output2 from ndisc_send_skb+0x4cc/0x81c ndisc_send_skb from addrconf_rs_timer+0xb0/0x2f8 addrconf_rs_timer from call_timer_fn+0xb4/0x33c call_timer_fn from expire_timers+0xb4/0x10c expire_timers from run_timer_softirq+0xf8/0x2a8 run_timer_softirq from __do_softirq+0xd4/0x5fc __do_softirq from __irq_exit_rcu+0x138/0x17c __irq_exit_rcu from irq_exit+0x8/0x28 irq_exit from __irq_svc+0x90/0xbc Exception stack(0xc1001f20 to 0xc1001f68) 1f20: ffffffff ffffffff 00000001 c011f840 c100e000 c100e000 c1009314 c1009370 1f40: c10f0c1a c0d5e564 c0f5da8c 00000000 00000000 c1001f70 c010f0bc c010f0c0 1f60: 600f0013 ffffffff __irq_svc from arch_cpu_idle+0x30/0x3c arch_cpu_idle from default_idle_call+0x44/0xac default_idle_call from do_idle+0xc8/0x138 do_idle from cpu_startup_entry+0x18/0x1c cpu_startup_entry from rest_init+0xcc/0x168 rest_init from arch_post_acpi_subsys_init+0x0/0x8 Fix this by using spin_lock_irqsave/spin_lock_irqrestore also inside lan966x_ptp_irq_handler. Fixes: e85a96e ("net: lan966x: Add support for ptp interrupts") Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> Link: https://lore.kernel.org/r/20230217210917.2649365-1-horatiu.vultur@microchip.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
code path: ocfs2_ioctl_move_extents ocfs2_move_extents ocfs2_defrag_extent __ocfs2_move_extent + ocfs2_journal_access_di + ocfs2_split_extent //sub-paths call jbd2_journal_restart + ocfs2_journal_dirty //crash by jbs2 ASSERT crash stacks: PID: 11297 TASK: ffff974a676dcd00 CPU: 67 COMMAND: "defragfs.ocfs2" #0 [ffffb25d8dad3900] machine_kexec at ffffffff8386fe01 #1 [ffffb25d8dad3958] __crash_kexec at ffffffff8395959d #2 [ffffb25d8dad3a20] crash_kexec at ffffffff8395a45d #3 [ffffb25d8dad3a38] oops_end at ffffffff83836d3f #4 [ffffb25d8dad3a58] do_trap at ffffffff83833205 #5 [ffffb25d8dad3aa0] do_invalid_op at ffffffff83833aa6 #6 [ffffb25d8dad3ac0] invalid_op at ffffffff84200d18 [exception RIP: jbd2_journal_dirty_metadata+0x2ba] RIP: ffffffffc09ca54a RSP: ffffb25d8dad3b70 RFLAGS: 00010207 RAX: 0000000000000000 RBX: ffff9706eedc5248 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff97337029ea28 RDI: ffff9706eedc5250 RBP: ffff9703c3520200 R8: 000000000f46b0b2 R9: 0000000000000000 R10: 0000000000000001 R11: 00000001000000fe R12: ffff97337029ea28 R13: 0000000000000000 R14: ffff9703de59bf60 R15: ffff9706eedc5250 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffffb25d8dad3ba8] ocfs2_journal_dirty at ffffffffc137fb95 [ocfs2] #8 [ffffb25d8dad3be8] __ocfs2_move_extent at ffffffffc139a950 [ocfs2] #9 [ffffb25d8dad3c80] ocfs2_defrag_extent at ffffffffc139b2d2 [ocfs2] Analysis This bug has the same root cause of 'commit 7f27ec9 ("ocfs2: call ocfs2_journal_access_di() before ocfs2_journal_dirty() in ocfs2_write_end_nolock()")'. For this bug, jbd2_journal_restart() is called by ocfs2_split_extent() during defragmenting. How to fix For ocfs2_split_extent() can handle journal operations totally by itself. Caller doesn't need to call journal access/dirty pair, and caller only needs to call journal start/stop pair. The fix method is to remove journal access/dirty from __ocfs2_move_extent(). The discussion for this patch: https://oss.oracle.com/pipermail/ocfs2-devel/2023-February/000647.html Link: https://lkml.kernel.org/r/20230217003717.32469-1-heming.zhao@suse.com Signed-off-by: Heming Zhao <heming.zhao@suse.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sai Krishna says: ==================== octeontx2: Miscellaneous fixes This patchset includes following fixes. Patch #1 Fix for the race condition while updating APR table Patch #2 Fix end bit position in NPC scan config Patch #3 Fix depth of CAM, MEM table entries Patch #4 Fix in increase the size of DMAC filter flows Patch #5 Fix driver crash resulting from invalid interface type information retrieved from firmware Patch #6 Fix incorrect mask used while installing filters involving fragmented packets Patch #7 Fixes for NPC field hash extract w.r.t IPV6 hash reduction, IPV6 filed hash configuration. Patch #8 Fix for NPC hardware parser configuration destination address hash, IPV6 endianness issues. Patch #9 Fix for skipping mbox initialization for PFs disabled by firmware. Patch #10 Fix disabling packet I/O in case of mailbox timeout. Patch #11 Fix detaching LF resources in case of VF probe fail. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
…linux/kernel/git/tip/tip Pull SMP updates from Thomas Gleixner: "A large update for SMP management: - Parallel CPU bringup The reason why people are interested in parallel bringup is to shorten the (kexec) reboot time of cloud servers to reduce the downtime of the VM tenants. The current fully serialized bringup does the following per AP: 1) Prepare callbacks (allocate, intialize, create threads) 2) Kick the AP alive (e.g. INIT/SIPI on x86) 3) Wait for the AP to report alive state 4) Let the AP continue through the atomic bringup 5) Let the AP run the threaded bringup to full online state There are two significant delays: #3 The time for an AP to report alive state in start_secondary() on x86 has been measured in the range between 350us and 3.5ms depending on vendor and CPU type, BIOS microcode size etc. #4 The atomic bringup does the microcode update. This has been measured to take up to ~8ms on the primary threads depending on the microcode patch size to apply. On a two socket SKL server with 56 cores (112 threads) the boot CPU spends on current mainline about 800ms busy waiting for the APs to come up and apply microcode. That's more than 80% of the actual onlining procedure. This can be reduced significantly by splitting the bringup mechanism into two parts: 1) Run the prepare callbacks and kick the AP alive for each AP which needs to be brought up. The APs wake up, do their firmware initialization and run the low level kernel startup code including microcode loading in parallel up to the first synchronization point. (#1 and #2 above) 2) Run the rest of the bringup code strictly serialized per CPU (#3 - #5 above) as it's done today. Parallelizing that stage of the CPU bringup might be possible in theory, but it's questionable whether required surgery would be justified for a pretty small gain. If the system is large enough the first AP is already waiting at the first synchronization point when the boot CPU finished the wake-up of the last AP. That reduces the AP bringup time on that SKL from ~800ms to ~80ms, i.e. by a factor ~10x. The actual gain varies wildly depending on the system, CPU, microcode patch size and other factors. There are some opportunities to reduce the overhead further, but that needs some deep surgery in the x86 CPU bringup code. For now this is only enabled on x86, but the core functionality obviously works for all SMP capable architectures. - Enhancements for SMP function call tracing so it is possible to locate the scheduling and the actual execution points. That allows to measure IPI delivery time precisely" * tag 'smp-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits) trace,smp: Add tracepoints for scheduling remotelly called functions trace,smp: Add tracepoints around remotelly called functions MAINTAINERS: Add CPU HOTPLUG entry x86/smpboot: Fix the parallel bringup decision x86/realmode: Make stack lock work in trampoline_compat() x86/smp: Initialize cpu_primary_thread_mask late cpu/hotplug: Fix off by one in cpuhp_bringup_mask() x86/apic: Fix use of X{,2}APIC_ENABLE in asm with older binutils x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it x86/smpboot: Support parallel startup of secondary CPUs x86/smpboot: Implement a bit spinlock to protect the realmode stack x86/apic: Save the APIC virtual base address cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE x86/apic: Provide cpu_primary_thread mask x86/smpboot: Enable split CPU startup cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanism cpu/hotplug: Reset task stack state in _cpu_up() cpu/hotplug: Remove unused state functions riscv: Switch to hotplug core state synchronization parisc: Switch to hotplug core state synchronization ...
…git/vgupta/arc Pull ARC updates from Vineet Gupta: - fixes for -Wmissing-prototype warnings - missing compiler barrier in relaxed atomics - some uaccess simplification, declutter - removal of massive glocal struct cpuinfo_arc from bootlog code - __switch_to consolidation (removal of inline asm variant) - use GP to cache task pointer (vs. r25) - misc rework of entry code * tag 'arc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (24 commits) ARC: boot log: fix warning arc: Explicitly include correct DT includes ARC: pt_regs: create seperate type for ecr ARCv2: entry: rearrange pt_regs slightly ARC: entry: replace 8 byte ADD.ne with 4 byte ADD2.ne ARC: entry: replace 8 byte OR with 4 byte BSET ARC: entry: Add more common chores to EXCEPTION_PROLOGUE ARC: entry: EV_MachineCheck dont re-read ECR ARC: entry: ARcompact EV_ProtV to use r10 directly ARC: entry: rework (non-functional) ARC: __switch_to: move ksp to thread_info from thread_struct ARC: __switch_to: asm with dwarf ops (vs. inline asm) ARC: kernel stack: INIT_THREAD need not setup @init_stack in @ksp ARC: entry: use gp to cache task pointer (vs. r25) ARC: boot log: eliminate struct cpuinfo_arc #4: boot log per ISA ARC: boot log: eliminate struct cpuinfo_arc #3: don't export ARC: boot log: eliminate struct cpuinfo_arc #2: cache ARC: boot log: eliminate struct cpuinfo_arc #1: mm ARCv2: memset: don't prefetch for len == 0 which happens a alot ARC: uaccess: elide unaliged handling if hardware supports ...
Chuyi Zhou says: ==================== Relax allowlist for open-coded css_task iter Hi, The patchset aims to relax the allowlist for open-coded css_task iter suggested by Alexei[1]. Please see individual patches for more details. And comments are always welcome. Patch summary: * Patch #1: Relax the allowlist and let css_task iter can be used in bpf iters and any sleepable progs. * Patch #2: Add a test in cgroup_iters.c which demonstrates how css_task iters can be combined with cgroup iter. * Patch #3: Add a test to prove css_task iter can be used in normal * sleepable progs. link[1]:https://lore.kernel.org/lkml/CAADnVQKafk_junRyE=-FVAik4hjTRDtThymYGEL8hGTuYoOGpA@mail.gmail.com/ --- Changes in v2: * Fix the incorrect logic in check_css_task_iter_allowlist. Use expected_attach_type to check whether we are using bpf_iters. * Link to v1:https://lore.kernel.org/bpf/20231022154527.229117-1-zhouchuyi@bytedance.com/T/#m946f9cde86b44a13265d9a44c5738a711eb578fd Changes in v3: * Add a testcase to prove css_task can be used in fentry.s * Link to v2:https://lore.kernel.org/bpf/20231024024240.42790-1-zhouchuyi@bytedance.com/T/#m14a97041ff56c2df21bc0149449abd275b73f6a3 Changes in v4: * Add Yonghong's ack for patch #1 and patch #2. * Solve Yonghong's comments for patch #2 * Move prog 'iter_css_task_for_each_sleep' from iters_task_failure.c to iters_css_task.c. Use RUN_TESTS to prove we can load this prog. * Link to v3:https://lore.kernel.org/bpf/20231025075914.30979-1-zhouchuyi@bytedance.com/T/#m3200d8ad29af4ffab97588e297361d0a45d7585d --- ==================== Link: https://lore.kernel.org/r/20231031050438.93297-1-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
KMSAN reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was stored to memory at: virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline] virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was created at: slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline] virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline] virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: vsock-loopback vsock_loopback_work ===================================================== The following simple reproducer can cause the issue described above: int main(void) { int sock; struct sockaddr_vm addr = { .svm_family = AF_VSOCK, .svm_cid = VMADDR_CID_ANY, .svm_port = 1234, }; sock = socket(AF_VSOCK, SOCK_STREAM, 0); connect(sock, (struct sockaddr *)&addr, sizeof(addr)); return 0; } This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the `struct virtio_vsock_hdr` are not initialized when a new skb is allocated in `virtio_transport_init_hdr()`. This patch resolves the issue by initializing these fields during allocation. Fixes: 71dc9ec ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/20231104150531.257952-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================================================== WARNING: possible circular locking dependency detected 6.5.0-kfd-yangp #2289 Not tainted ------------------------------------------------------ kworker/0:2/996 is trying to acquire lock: (srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x5/0x1a0 but task is already holding lock: ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}, at: process_one_work+0x211/0x560 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}: __flush_work+0x88/0x4f0 svm_range_list_lock_and_flush_work+0x3d/0x110 [amdgpu] svm_range_set_attr+0xd6/0x14c0 [amdgpu] kfd_ioctl+0x1d1/0x630 [amdgpu] __x64_sys_ioctl+0x88/0xc0 -> #2 (&info->lock#2){+.+.}-{3:3}: __mutex_lock+0x99/0xc70 amdgpu_amdkfd_gpuvm_restore_process_bos+0x54/0x740 [amdgpu] restore_process_helper+0x22/0x80 [amdgpu] restore_process_worker+0x2d/0xa0 [amdgpu] process_one_work+0x29b/0x560 worker_thread+0x3d/0x3d0 -> #1 ((work_completion)(&(&process->restore_work)->work)){+.+.}-{0:0}: __flush_work+0x88/0x4f0 __cancel_work_timer+0x12c/0x1c0 kfd_process_notifier_release_internal+0x37/0x1f0 [amdgpu] __mmu_notifier_release+0xad/0x240 exit_mmap+0x6a/0x3a0 mmput+0x6a/0x120 do_exit+0x322/0xb90 do_group_exit+0x37/0xa0 __x64_sys_exit_group+0x18/0x20 do_syscall_64+0x38/0x80 -> #0 (srcu){.+.+}-{0:0}: __lock_acquire+0x1521/0x2510 lock_sync+0x5f/0x90 __synchronize_srcu+0x4f/0x1a0 __mmu_notifier_release+0x128/0x240 exit_mmap+0x6a/0x3a0 mmput+0x6a/0x120 svm_range_deferred_list_work+0x19f/0x350 [amdgpu] process_one_work+0x29b/0x560 worker_thread+0x3d/0x3d0 other info that might help us debug this: Chain exists of: srcu --> &info->lock#2 --> (work_completion)(&svms->deferred_list_work) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&svms->deferred_list_work)); lock(&info->lock#2); lock((work_completion)(&svms->deferred_list_work)); sync(srcu); Signed-off-by: Philip Yang <Philip.Yang@amd.com> Reviewed-by: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
The variable rmnet_link_ops assign a *bigger* maxtype which leads to a global out-of-bounds read when parsing the netlink attributes. See bug trace below: ================================================================== BUG: KASAN: global-out-of-bounds in validate_nla lib/nlattr.c:386 [inline] BUG: KASAN: global-out-of-bounds in __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600 Read of size 1 at addr ffffffff92c438d0 by task syz-executor.6/84207 CPU: 0 PID: 84207 Comm: syz-executor.6 Tainted: G N 6.1.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x8b/0xb3 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x172/0x475 mm/kasan/report.c:395 kasan_report+0xbb/0x1c0 mm/kasan/report.c:495 validate_nla lib/nlattr.c:386 [inline] __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600 __nla_parse+0x3e/0x50 lib/nlattr.c:697 nla_parse_nested_deprecated include/net/netlink.h:1248 [inline] __rtnl_newlink+0x50a/0x1880 net/core/rtnetlink.c:3485 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3594 rtnetlink_rcv_msg+0x43c/0xd70 net/core/rtnetlink.c:6091 netlink_rcv_skb+0x14f/0x410 net/netlink/af_netlink.c:2540 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x54e/0x800 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x930/0xe50 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0x154/0x190 net/socket.c:734 ____sys_sendmsg+0x6df/0x840 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fdcf2072359 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdcf13e3168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdcf219ff80 RCX: 00007fdcf2072359 RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000003 RBP: 00007fdcf20bd493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffbb8d7bdf R14: 00007fdcf13e3300 R15: 0000000000022000 </TASK> The buggy address belongs to the variable: rmnet_policy+0x30/0xe0 The buggy address belongs to the physical page: page:0000000065bdeb3c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x155243 flags: 0x200000000001000(reserved|node=0|zone=2) raw: 0200000000001000 ffffea00055490c8 ffffea00055490c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffffffff92c43780: f9 f9 f9 f9 00 00 00 02 f9 f9 f9 f9 00 00 00 07 ffffffff92c43800: f9 f9 f9 f9 00 00 00 05 f9 f9 f9 f9 06 f9 f9 f9 >ffffffff92c43880: f9 f9 f9 f9 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 ^ ffffffff92c43900: 00 00 00 00 00 00 00 00 07 f9 f9 f9 f9 f9 f9 f9 ffffffff92c43980: 00 00 00 07 f9 f9 f9 f9 00 00 00 05 f9 f9 f9 f9 According to the comment of `nla_parse_nested_deprecated`, the maxtype should be len(destination array) - 1. Hence use `IFLA_RMNET_MAX` here. Fixes: 14452ca ("net: qualcomm: rmnet: Export mux_id and flags to netlink") Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240110061400.3356108-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
…n,npcm750-pwm-fan Commit 89fec12 ("hwmon: (npcm750-pwm-fan) Add NPCM8xx support") introduced support for PWM fans on Nuvoton's npcm845 SoC. This chip supports three PWM modules with four PWM channels each. The older npcm750 only supported two PWM modules. The commit did not take into account that the older SoC only supported two PWM modules. This results in a crash if npcm750 is instantiated when the code attempts to instantiate the non-existing third PWM module. Unable to handle kernel paging request at virtual address e0aa2000 when write [e0aa2000] *pgd=04ab6811, *pte=00000000, *ppte=00000000 Internal error: Oops: 807 [#1] SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Tainted: G N 6.7.0-next-20240112-dirty #3 Hardware name: NPCM7XX Chip family PC is at npcm7xx_pwm_fan_probe+0x204/0x890 LR is at arm_heavy_mb+0x1c/0x38 Fix the problem by detecting the number of supported PWM modules in the probe function and only instantiating the supported modules. Fixes: 89fec12 ("hwmon: (npcm750-pwm-fan) Add NPCM8xx support") Cc: Tomer Maimon <tmaimon77@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The test_tag test triggers an unhandled page fault: # ./test_tag [ 130.640218] CPU 0 Unable to handle kernel paging request at virtual address ffff80001b898004, era == 9000000003137f7c, ra == 9000000003139e70 [ 130.640501] Oops[#3]: [ 130.640553] CPU: 0 PID: 1326 Comm: test_tag Tainted: G D O 6.7.0-rc4-loong-devel-gb62ab1a397cf #47 61985c1d94084daa2432f771daa45b56b10d8d2a [ 130.640764] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 [ 130.640874] pc 9000000003137f7c ra 9000000003139e70 tp 9000000104cb4000 sp 9000000104cb7a40 [ 130.641001] a0 ffff80001b894000 a1 ffff80001b897ff8 a2 000000006ba210be a3 0000000000000000 [ 130.641128] a4 000000006ba210be a5 00000000000000f1 a6 00000000000000b3 a7 0000000000000000 [ 130.641256] t0 0000000000000000 t1 00000000000007f6 t2 0000000000000000 t3 9000000004091b70 [ 130.641387] t4 000000006ba210be t5 0000000000000004 t6 fffffffffffffff0 t7 90000000040913e0 [ 130.641512] t8 0000000000000005 u0 0000000000000dc0 s9 0000000000000009 s0 9000000104cb7ae0 [ 130.641641] s1 00000000000007f6 s2 0000000000000009 s3 0000000000000095 s4 0000000000000000 [ 130.641771] s5 ffff80001b894000 s6 ffff80001b897fb0 s7 9000000004090c50 s8 0000000000000000 [ 130.641900] ra: 9000000003139e70 build_body+0x1fcc/0x4988 [ 130.642007] ERA: 9000000003137f7c build_body+0xd8/0x4988 [ 130.642112] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) [ 130.642261] PRMD: 00000004 (PPLV0 +PIE -PWE) [ 130.642353] EUEN: 00000003 (+FPE +SXE -ASXE -BTE) [ 130.642458] ECFG: 00071c1c (LIE=2-4,10-12 VS=7) [ 130.642554] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) [ 130.642658] BADV: ffff80001b898004 [ 130.642719] PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) [ 130.642815] Modules linked in: [last unloaded: bpf_testmod(O)] [ 130.642924] Process test_tag (pid: 1326, threadinfo=00000000f7f4015f, task=000000006499f9fd) [ 130.643062] Stack : 0000000000000000 9000000003380724 0000000000000000 0000000104cb7be8 [ 130.643213] 0000000000000000 25af8d9b6e600558 9000000106250ea0 9000000104cb7ae0 [ 130.643378] 0000000000000000 0000000000000000 9000000104cb7be8 90000000049f6000 [ 130.643538] 0000000000000090 9000000106250ea0 ffff80001b894000 ffff80001b894000 [ 130.643685] 00007ffffb917790 900000000313ca94 0000000000000000 0000000000000000 [ 130.643831] ffff80001b894000 0000000000000ff7 0000000000000000 9000000100468000 [ 130.643983] 0000000000000000 0000000000000000 0000000000000040 25af8d9b6e600558 [ 130.644131] 0000000000000bb7 ffff80001b894048 0000000000000000 0000000000000000 [ 130.644276] 9000000104cb7be8 90000000049f6000 0000000000000090 9000000104cb7bdc [ 130.644423] ffff80001b894000 0000000000000000 00007ffffb917790 90000000032acfb0 [ 130.644572] ... [ 130.644629] Call Trace: [ 130.644641] [<9000000003137f7c>] build_body+0xd8/0x4988 [ 130.644785] [<900000000313ca94>] bpf_int_jit_compile+0x228/0x4ec [ 130.644891] [<90000000032acfb0>] bpf_prog_select_runtime+0x158/0x1b0 [ 130.645003] [<90000000032b3504>] bpf_prog_load+0x760/0xb44 [ 130.645089] [<90000000032b6744>] __sys_bpf+0xbb8/0x2588 [ 130.645175] [<90000000032b8388>] sys_bpf+0x20/0x2c [ 130.645259] [<9000000003f6ab38>] do_syscall+0x7c/0x94 [ 130.645369] [<9000000003121c5c>] handle_syscall+0xbc/0x158 [ 130.645507] [ 130.645539] Code: 380839f6 380831f9 28412bae <24000ca6> 004081ad 0014cb50 004083e8 02bff34c 58008e91 [ 130.645729] [ 130.646418] ---[ end trace 0000000000000000 ]--- On my machine, which has CONFIG_PAGE_SIZE_16KB=y, the test failed at loading a BPF prog with 2039 instructions: prog = (struct bpf_prog *)ffff80001b894000 insn = (struct bpf_insn *)(prog->insnsi)ffff80001b894048 insn + 2039 = (struct bpf_insn *)ffff80001b898000 <- end of the page In the build_insn() function, we are trying to access next instruction unconditionally, i.e. `(insn + 1)->imm`. The address lies in the next page and can be not owned by the current process, thus an page fault is inevitable and then segfault. So, let's access next instruction only under `dst = imm64` context. With this fix, we have: # ./test_tag test_tag: OK (40945 tests) Fixes: bbfddb9 ("LoongArch: BPF: Avoid declare variables in switch-case") Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Andrii Nakryiko says: ==================== Tighten up arg:ctx type enforcement Follow up fixes for kernel-side and libbpf-side logic around handling arg:ctx (__arg_ctx) tagged arguments of BPF global subprogs. Patch #1 adds libbpf feature detection of kernel-side __arg_ctx support to avoid unnecessary rewriting BTF types. With stricter kernel-side type enforcement this is now mandatory to avoid problems with using `struct bpf_user_pt_regs_t` instead of actual typedef. For __arg_ctx tagged arguments verifier is now supporting either `bpf_user_pt_regs_t` typedef or resolves it down to the actual struct (pt_regs/user_pt_regs/user_regs_struct), depending on architecture), but for old kernels without __arg_ctx support it's more backwards compatible for libbpf to use `struct bpf_user_pt_regs_t` rewrite which will work on wider range of kernels. So feature detection prevent libbpf accidentally breaking global subprogs on new kernels. We also adjust selftests to do similar feature detection (much simpler, but potentially breaking due to kernel source code refactoring, which is fine for selftests), and skip tests expecting libbpf's BTF type rewrites. Patch #2 is preparatory refactoring for patch #3 which adds type enforcement for arg:ctx tagged global subprog args. See the patch for specifics. Patch #4 adds many new cases to ensure type logic works as expected. Finally, patch #5 adds a relevant subset of kernel-side type checks to __arg_ctx cases that libbpf supports rewrite of. In libbpf's case, type violations are reported as warnings and BTF rewrite is not performed, which will eventually lead to BPF verifier complaining at program verification time. Good care was taken to avoid conflicts between bpf and bpf-next tree (which has few follow up refactorings in the same code area). Once trees converge some of the code will be moved around a bit (and some will be deleted), but with no change to functionality or general shape of the code. v2->v3: - support `bpf_user_pt_regs_t` typedef for KPROBE and PERF_EVENT (CI); v1->v2: - add user_pt_regs and user_regs_struct support for PERF_EVENT (CI); - drop FEAT_ARG_CTX_TAG enum leftover from patch #1; - fix warning about default: without break in the switch (CI). ==================== Link: https://lore.kernel.org/r/20240118033143.3384355-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Petr Machata says: ==================== mlxsw: Miscellaneous fixes This patchset is a bric-a-brac of fixes for bugs impacting mlxsw. - Patches #1 and #2 fix issues in ACL handling error paths. - Patch #3 fixes stack corruption in ACL code that a recent FW update has uncovered. - Patch #4 fixes an issue in handling of IPIP next hops. - Patch #5 fixes a typo in a the qos_pfc selftest - Patch #6 fixes the same selftest to work with 8-lane ports. ==================== Link: https://lore.kernel.org/r/cover.1705502064.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When I was testing mongodb over bcachefs with compression, there is a lockdep warning when snapshotting mongodb data volume. $ cat test.sh prog=bcachefs $prog subvolume create /mnt/data $prog subvolume create /mnt/data/snapshots while true;do $prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s) sleep 1s done $ cat /etc/mongodb.conf systemLog: destination: file logAppend: true path: /mnt/data/mongod.log storage: dbPath: /mnt/data/ lockdep reports: [ 3437.452330] ====================================================== [ 3437.452750] WARNING: possible circular locking dependency detected [ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E [ 3437.453562] ------------------------------------------------------ [ 3437.453981] bcachefs/35533 is trying to acquire lock: [ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190 [ 3437.454875] but task is already holding lock: [ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.456009] which lock already depends on the new lock. [ 3437.456553] the existing dependency chain (in reverse order) is: [ 3437.457054] -> #3 (&type->s_umount_key#48){.+.+}-{3:3}: [ 3437.457507] down_read+0x3e/0x170 [ 3437.457772] bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.458206] __x64_sys_ioctl+0x93/0xd0 [ 3437.458498] do_syscall_64+0x42/0xf0 [ 3437.458779] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.459155] -> #2 (&c->snapshot_create_lock){++++}-{3:3}: [ 3437.459615] down_read+0x3e/0x170 [ 3437.459878] bch2_truncate+0x82/0x110 [bcachefs] [ 3437.460276] bchfs_truncate+0x254/0x3c0 [bcachefs] [ 3437.460686] notify_change+0x1f1/0x4a0 [ 3437.461283] do_truncate+0x7f/0xd0 [ 3437.461555] path_openat+0xa57/0xce0 [ 3437.461836] do_filp_open+0xb4/0x160 [ 3437.462116] do_sys_openat2+0x91/0xc0 [ 3437.462402] __x64_sys_openat+0x53/0xa0 [ 3437.462701] do_syscall_64+0x42/0xf0 [ 3437.462982] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.463359] -> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}: [ 3437.463843] down_write+0x3b/0xc0 [ 3437.464223] bch2_write_iter+0x5b/0xcc0 [bcachefs] [ 3437.464493] vfs_write+0x21b/0x4c0 [ 3437.464653] ksys_write+0x69/0xf0 [ 3437.464839] do_syscall_64+0x42/0xf0 [ 3437.465009] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.465231] -> #0 (sb_writers#10){.+.+}-{0:0}: [ 3437.465471] __lock_acquire+0x1455/0x21b0 [ 3437.465656] lock_acquire+0xc6/0x2b0 [ 3437.465822] mnt_want_write+0x46/0x1a0 [ 3437.465996] filename_create+0x62/0x190 [ 3437.466175] user_path_create+0x2d/0x50 [ 3437.466352] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.466617] __x64_sys_ioctl+0x93/0xd0 [ 3437.466791] do_syscall_64+0x42/0xf0 [ 3437.466957] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.467180] other info that might help us debug this: [ 3437.469670] 2 locks held by bcachefs/35533: other info that might help us debug this: [ 3437.467507] Chain exists of: sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48 [ 3437.467979] Possible unsafe locking scenario: [ 3437.468223] CPU0 CPU1 [ 3437.468405] ---- ---- [ 3437.468585] rlock(&type->s_umount_key#48); [ 3437.468758] lock(&c->snapshot_create_lock); [ 3437.469030] lock(&type->s_umount_key#48); [ 3437.469291] rlock(sb_writers#10); [ 3437.469434] *** DEADLOCK *** [ 3437.469670] 2 locks held by bcachefs/35533: [ 3437.469838] #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs] [ 3437.470294] #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs] [ 3437.470744] stack backtrace: [ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G E 6.7.0-rc7-custom+ #85 [ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 3437.471694] Call Trace: [ 3437.471795] <TASK> [ 3437.471884] dump_stack_lvl+0x57/0x90 [ 3437.472035] check_noncircular+0x132/0x150 [ 3437.472202] __lock_acquire+0x1455/0x21b0 [ 3437.472369] lock_acquire+0xc6/0x2b0 [ 3437.472518] ? filename_create+0x62/0x190 [ 3437.472683] ? lock_is_held_type+0x97/0x110 [ 3437.472856] mnt_want_write+0x46/0x1a0 [ 3437.473025] ? filename_create+0x62/0x190 [ 3437.473204] filename_create+0x62/0x190 [ 3437.473380] user_path_create+0x2d/0x50 [ 3437.473555] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs] [ 3437.473819] ? lock_acquire+0xc6/0x2b0 [ 3437.474002] ? __fget_files+0x2a/0x190 [ 3437.474195] ? __fget_files+0xbc/0x190 [ 3437.474380] ? lock_release+0xc5/0x270 [ 3437.474567] ? __x64_sys_ioctl+0x93/0xd0 [ 3437.474764] ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs] [ 3437.475090] __x64_sys_ioctl+0x93/0xd0 [ 3437.475277] do_syscall_64+0x42/0xf0 [ 3437.475454] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 3437.475691] RIP: 0033:0x7f2743c313af ====================================================== In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally and unlock it at the end of the function. There is a comment "why do we need this lock?" about the lock coming from commit 42d2373 ("bcachefs: Snapshot creation, deletion") The reason is that __bch2_ioctl_subvolume_create() calls sync_inodes_sb() which enforce locked s_umount to writeback all dirty nodes before doing snapshot works. Fix it by read locking s_umount for snapshotting only and unlocking s_umount after sync_inodes_sb(). Signed-off-by: Su Yue <glass.su@suse.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
…rnel/git/netfilter/nf-next Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next: Patch #1 skips transaction if object type provides no .update interface. Patch #2 skips NETDEV_CHANGENAME which is unused. Patch #3 enables conntrack to handle Multicast Router Advertisements and Multicast Router Solicitations from the Multicast Router Discovery protocol (RFC4286) as untracked opposed to invalid packets. From Linus Luessing. Patch #4 updates DCCP conntracker to mark invalid as invalid, instead of dropping them, from Jason Xing. Patch #5 uses NF_DROP instead of -NF_DROP since NF_DROP is 0, also from Jason. Patch #6 removes reference in netfilter's sysctl documentation on pickup entries which were already removed by Florian Westphal. Patch #7 removes check for IPS_OFFLOAD flag to disable early drop which allows to evict entries from the conntrack table, also from Florian. Patches #8 to #16 updates nf_tables pipapo set backend to allocate the datastructure copy on-demand from preparation phase, to better deal with OOM situations where .commit step is too late to fail. Series from Florian Westphal. Patch #17 adds a selftest with packetdrill to cover conntrack TCP state transitions, also from Florian. Patch #18 use GFP_KERNEL to clone elements from control plane to avoid quick atomic reserves exhaustion with large sets, reporter refers to million entries magnitude. * tag 'nf-next-24-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: allow clone callbacks to sleep selftests: netfilter: add packetdrill based conntrack tests netfilter: nft_set_pipapo: remove dirty flag netfilter: nft_set_pipapo: move cloning of match info to insert/removal path netfilter: nft_set_pipapo: prepare pipapo_get helper for on-demand clone netfilter: nft_set_pipapo: merge deactivate helper into caller netfilter: nft_set_pipapo: prepare walk function for on-demand clone netfilter: nft_set_pipapo: prepare destroy function for on-demand clone netfilter: nft_set_pipapo: make pipapo_clone helper return NULL netfilter: nft_set_pipapo: move prove_locking helper around netfilter: conntrack: remove flowtable early-drop test netfilter: conntrack: documentation: remove reference to non-existent sysctl netfilter: use NF_DROP instead of -NF_DROP netfilter: conntrack: dccp: try not to drop skb in conntrack netfilter: conntrack: fix ct-state for ICMPv6 Multicast Router Discovery netfilter: nf_tables: remove NETDEV_CHANGENAME from netdev chain event handler netfilter: nf_tables: skip transaction if update object is not implemented ==================== Link: https://lore.kernel.org/r/20240512161436.168973-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
…_child(). syzkaller reported KMSAN splat in tcp_create_openreq_child(). [0] The uninit variable is tcp_rsk(req)->ao_keyid. tcp_rsk(req)->ao_keyid is initialised only when tcp_conn_request() finds a valid TCP AO option in SYN. Then, tcp_rsk(req)->used_tcp_ao is set accordingly. Let's not read tcp_rsk(req)->ao_keyid when tcp_rsk(req)->used_tcp_ao is false. [0]: BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x198b/0x1ff0 net/ipv4/tcp_minisocks.c:610 tcp_create_openreq_child+0x198b/0x1ff0 net/ipv4/tcp_minisocks.c:610 tcp_v4_syn_recv_sock+0x18e/0x2170 net/ipv4/tcp_ipv4.c:1754 tcp_check_req+0x1a3e/0x20c0 net/ipv4/tcp_minisocks.c:852 tcp_v4_rcv+0x26a4/0x53a0 net/ipv4/tcp_ipv4.c:2265 ip_protocol_deliver_rcu+0x884/0x1270 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x30f/0x530 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x230/0x4c0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x10f7/0x13e0 net/ipv4/ip_input.c:639 ip_list_rcv+0x952/0x9c0 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5703 [inline] __netif_receive_skb_list_core+0xd92/0x11d0 net/core/dev.c:5751 __netif_receive_skb_list net/core/dev.c:5803 [inline] netif_receive_skb_list_internal+0xd8f/0x1350 net/core/dev.c:5895 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x3f2/0x990 net/core/dev.c:6246 e1000_clean+0x1fa4/0x5e50 drivers/net/ethernet/intel/e1000/e1000_main.c:3808 __napi_poll+0xd9/0x990 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x90f/0x17e0 net/core/dev.c:6962 handle_softirqs+0x152/0x6b0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0x5d/0x120 kernel/softirq.c:649 common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __msan_instrument_asm_store+0xd6/0xe0 arch_atomic_inc arch/x86/include/asm/atomic.h:53 [inline] raw_atomic_inc include/linux/atomic/atomic-arch-fallback.h:992 [inline] atomic_inc include/linux/atomic/atomic-instrumented.h:436 [inline] page_ref_inc include/linux/page_ref.h:153 [inline] folio_ref_inc include/linux/page_ref.h:160 [inline] filemap_map_order0_folio mm/filemap.c:3596 [inline] filemap_map_pages+0x11c7/0x2270 mm/filemap.c:3644 do_fault_around mm/memory.c:4879 [inline] do_read_fault mm/memory.c:4912 [inline] do_fault mm/memory.c:5051 [inline] do_pte_missing mm/memory.c:3897 [inline] handle_pte_fault mm/memory.c:5381 [inline] __handle_mm_fault mm/memory.c:5524 [inline] handle_mm_fault+0x3677/0x6f00 mm/memory.c:5689 do_user_addr_fault+0x1373/0x2b20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x54/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 Uninit was stored to memory at: tcp_create_openreq_child+0x1984/0x1ff0 net/ipv4/tcp_minisocks.c:611 tcp_v4_syn_recv_sock+0x18e/0x2170 net/ipv4/tcp_ipv4.c:1754 tcp_check_req+0x1a3e/0x20c0 net/ipv4/tcp_minisocks.c:852 tcp_v4_rcv+0x26a4/0x53a0 net/ipv4/tcp_ipv4.c:2265 ip_protocol_deliver_rcu+0x884/0x1270 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x30f/0x530 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x230/0x4c0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x10f7/0x13e0 net/ipv4/ip_input.c:639 ip_list_rcv+0x952/0x9c0 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5703 [inline] __netif_receive_skb_list_core+0xd92/0x11d0 net/core/dev.c:5751 __netif_receive_skb_list net/core/dev.c:5803 [inline] netif_receive_skb_list_internal+0xd8f/0x1350 net/core/dev.c:5895 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x3f2/0x990 net/core/dev.c:6246 e1000_clean+0x1fa4/0x5e50 drivers/net/ethernet/intel/e1000/e1000_main.c:3808 __napi_poll+0xd9/0x990 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x90f/0x17e0 net/core/dev.c:6962 handle_softirqs+0x152/0x6b0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0x5d/0x120 kernel/softirq.c:649 common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 Uninit was created at: __alloc_pages_noprof+0x82d/0xcb0 mm/page_alloc.c:4706 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page mm/slub.c:2265 [inline] allocate_slab mm/slub.c:2428 [inline] new_slab+0x2af/0x14e0 mm/slub.c:2481 ___slab_alloc+0xf73/0x3150 mm/slub.c:3667 __slab_alloc mm/slub.c:3757 [inline] __slab_alloc_node mm/slub.c:3810 [inline] slab_alloc_node mm/slub.c:3990 [inline] kmem_cache_alloc_noprof+0x53a/0x9f0 mm/slub.c:4009 reqsk_alloc_noprof net/ipv4/inet_connection_sock.c:920 [inline] inet_reqsk_alloc+0x63/0x700 net/ipv4/inet_connection_sock.c:951 tcp_conn_request+0x339/0x4860 net/ipv4/tcp_input.c:7177 tcp_v4_conn_request+0x13b/0x190 net/ipv4/tcp_ipv4.c:1719 tcp_rcv_state_process+0x2dd/0x4a10 net/ipv4/tcp_input.c:6711 tcp_v4_do_rcv+0xbee/0x10d0 net/ipv4/tcp_ipv4.c:1932 tcp_v4_rcv+0x3fad/0x53a0 net/ipv4/tcp_ipv4.c:2334 ip_protocol_deliver_rcu+0x884/0x1270 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x30f/0x530 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x230/0x4c0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x10f7/0x13e0 net/ipv4/ip_input.c:639 ip_list_rcv+0x952/0x9c0 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5703 [inline] __netif_receive_skb_list_core+0xd92/0x11d0 net/core/dev.c:5751 __netif_receive_skb_list net/core/dev.c:5803 [inline] netif_receive_skb_list_internal+0xd8f/0x1350 net/core/dev.c:5895 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x3f2/0x990 net/core/dev.c:6246 e1000_clean+0x1fa4/0x5e50 drivers/net/ethernet/intel/e1000/e1000_main.c:3808 __napi_poll+0xd9/0x990 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x90f/0x17e0 net/core/dev.c:6962 handle_softirqs+0x152/0x6b0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0x5d/0x120 kernel/softirq.c:649 common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 CPU: 0 PID: 239 Comm: modprobe Tainted: G B 6.10.0-rc7-01816-g852e42cc2dd4 #3 1107521f0c7b55c9309062382d0bda9f604dbb6d Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Fixes: 06b22ef ("net/tcp: Wire TCP-AO to request sockets") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://patch.msgid.link/20240714161719.6528-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When tries to demote 1G hugetlb folios, a lockdep warning is observed: ============================================ WARNING: possible recursive locking detected 6.10.0-rc6-00452-ga4d0275fa660-dirty #79 Not tainted -------------------------------------------- bash/710 is trying to acquire lock: ffffffff8f0a7850 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0x244/0x460 but task is already holding lock: ffffffff8f0a6f48 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0xae/0x460 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&h->resize_lock); lock(&h->resize_lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by bash/710: #0: ffff8f118439c3f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0 #1: ffff8f11893b9e88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0 #2: ffff8f1183dc4428 (kn->active#98){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0 #3: ffffffff8f0a6f48 (&h->resize_lock){+.+.}-{3:3}, at: demote_store+0xae/0x460 stack backtrace: CPU: 3 PID: 710 Comm: bash Not tainted 6.10.0-rc6-00452-ga4d0275fa660-dirty #79 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x68/0xa0 __lock_acquire+0x10f2/0x1ca0 lock_acquire+0xbe/0x2d0 __mutex_lock+0x6d/0x400 demote_store+0x244/0x460 kernfs_fop_write_iter+0x12c/0x1d0 vfs_write+0x380/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa61db14887 RSP: 002b:00007ffc56c48358 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fa61db14887 RDX: 0000000000000002 RSI: 000055a030050220 RDI: 0000000000000001 RBP: 000055a030050220 R08: 00007fa61dbd1460 R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007fa61dc1b780 R14: 00007fa61dc17600 R15: 00007fa61dc16a00 </TASK> Lockdep considers this an AA deadlock because the different resize_lock mutexes reside in the same lockdep class, but this is a false positive. Place them in distinct classes to avoid these warnings. Link: https://lkml.kernel.org/r/20240712031314.2570452-1-linmiaohe@huawei.com Fixes: 8531fc6 ("hugetlb: add hugetlb demote page support") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When using cachefiles, lockdep may emit something similar to the circular locking dependency notice below. The problem appears to stem from the following: (1) Cachefiles manipulates xattrs on the files in its cache when called from ->writepages(). (2) The setxattr() and removexattr() system call handlers get the name (and value) from userspace after taking the sb_writers lock, putting accesses of the vma->vm_lock and mm->mmap_lock inside of that. (3) The afs filesystem uses a per-inode lock to prevent multiple revalidation RPCs and in writeback vs truncate to prevent parallel operations from deadlocking against the server on one side and local page locks on the other. Fix this by moving the getting of the name and value in {get,remove}xattr() outside of the sb_writers lock. This also has the minor benefits that we don't need to reget these in the event of a retry and we never try to take the sb_writers lock in the event we can't pull the name and value into the kernel. Alternative approaches that might fix this include moving the dispatch of a write to the cache off to a workqueue or trying to do without the validation lock in afs. Note that this might also affect other filesystems that use netfslib and/or cachefiles. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-build2+ #956 Not tainted ------------------------------------------------------ fsstress/6050 is trying to acquire lock: ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0 but task is already holding lock: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&vma->vm_lock->lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_write+0x3b/0x50 vma_start_write+0x6b/0xa0 vma_link+0xcc/0x140 insert_vm_struct+0xb7/0xf0 alloc_bprm+0x2c1/0x390 kernel_execve+0x65/0x1a0 call_usermodehelper_exec_async+0x14d/0x190 ret_from_fork+0x24/0x40 ret_from_fork_asm+0x1a/0x30 -> #3 (&mm->mmap_lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 __might_fault+0x7c/0xb0 strncpy_from_user+0x25/0x160 removexattr+0x7f/0x100 __do_sys_fremovexattr+0x7e/0xb0 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (sb_writers#14){.+.+}-{0:0}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 percpu_down_read+0x3c/0x90 vfs_iocb_iter_write+0xe9/0x1d0 __cachefiles_write+0x367/0x430 cachefiles_issue_write+0x299/0x2f0 netfs_advance_write+0x117/0x140 netfs_write_folio.isra.0+0x5ca/0x6e0 netfs_writepages+0x230/0x2f0 afs_writepages+0x4d/0x70 do_writepages+0x1e8/0x3e0 filemap_fdatawrite_wbc+0x84/0xa0 __filemap_fdatawrite_range+0xa8/0xf0 file_write_and_wait_range+0x59/0x90 afs_release+0x10f/0x270 __fput+0x25f/0x3d0 __do_sys_close+0x43/0x70 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&vnode->validate_lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_read+0x95/0x200 afs_writepages+0x37/0x70 do_writepages+0x1e8/0x3e0 filemap_fdatawrite_wbc+0x84/0xa0 filemap_invalidate_inode+0x167/0x1e0 netfs_unbuffered_write_iter+0x1bd/0x2d0 vfs_write+0x22e/0x320 ksys_write+0xbc/0x130 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (mapping.invalidate_lock#3){++++}-{3:3}: check_noncircular+0x119/0x160 check_prev_add+0x195/0x430 __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_read+0x95/0x200 filemap_fault+0x26e/0x8b0 __do_fault+0x57/0xd0 do_pte_missing+0x23b/0x320 __handle_mm_fault+0x2d4/0x320 handle_mm_fault+0x14f/0x260 do_user_addr_fault+0x2a2/0x500 exc_page_fault+0x71/0x90 asm_exc_page_fault+0x22/0x30 other info that might help us debug this: Chain exists of: mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&vma->vm_lock->lock); lock(&mm->mmap_lock); lock(&vma->vm_lock->lock); rlock(mapping.invalidate_lock#3); *** DEADLOCK *** 1 lock held by fsstress/6050: #0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250 stack backtrace: CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ #956 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x80 check_noncircular+0x119/0x160 ? queued_spin_lock_slowpath+0x4be/0x510 ? __pfx_check_noncircular+0x10/0x10 ? __pfx_queued_spin_lock_slowpath+0x10/0x10 ? mark_lock+0x47/0x160 ? init_chain_block+0x9c/0xc0 ? add_chain_block+0x84/0xf0 check_prev_add+0x195/0x430 __lock_acquire+0xaf0/0xd80 ? __pfx___lock_acquire+0x10/0x10 ? __lock_release.isra.0+0x13b/0x230 lock_acquire.part.0+0x103/0x280 ? filemap_fault+0x26e/0x8b0 ? __pfx_lock_acquire.part.0+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd7/0x120 down_read+0x95/0x200 ? filemap_fault+0x26e/0x8b0 ? __pfx_down_read+0x10/0x10 ? __filemap_get_folio+0x25/0x1a0 filemap_fault+0x26e/0x8b0 ? __pfx_filemap_fault+0x10/0x10 ? find_held_lock+0x7c/0x90 ? __pfx___lock_release.isra.0+0x10/0x10 ? __pte_offset_map+0x99/0x110 __do_fault+0x57/0xd0 do_pte_missing+0x23b/0x320 __handle_mm_fault+0x2d4/0x320 ? __pfx___handle_mm_fault+0x10/0x10 handle_mm_fault+0x14f/0x260 do_user_addr_fault+0x2a2/0x500 exc_page_fault+0x71/0x90 asm_exc_page_fault+0x22/0x30 Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/2136178.1721725194@warthog.procyon.org.uk cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Christian Brauner <brauner@kernel.org> cc: Jan Kara <jack@suse.cz> cc: Jeff Layton <jlayton@kernel.org> cc: Gao Xiang <xiang@kernel.org> cc: Matthew Wilcox <willy@infradead.org> cc: netfs@lists.linux.dev cc: linux-erofs@lists.ozlabs.org cc: linux-fsdevel@vger.kernel.org [brauner: fix minor issues] Signed-off-by: Christian Brauner <brauner@kernel.org>
Add the ability to clear/reset the lost value from the output of 'auditctl -s':
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