pkg/report: strip "panic_on_warn set" more aggressively

KMSAN reports can be short, but still include full stack. The added test is only 28 lines, so reduce the threshold from 40 to 25 lines.
google · Apr 7, 2018 · d70ffd1 · d70ffd1
1 parent 66f22a7
commit d70ffd1
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Showing 2 changed files with 128 additions and 1 deletion.
diff --git a/pkg/report/linux.go b/pkg/report/linux.go
@@ -178,7 +178,7 @@ func (ctx *linux) Parse(output []byte) *Report {
 				skipLine := skipText
 				if bytes.Contains(ln, []byte("Disabling lock debugging due to kernel taint")) {
 					skipLine = true
-				} else if textLines > 40 &&
+				} else if textLines > 25 &&
 					bytes.Contains(ln, []byte("Kernel panic - not syncing")) {
 					// If panic_on_warn set, then we frequently have 2 stacks:
 					// one for the actual report (or maybe even more than one),

diff --git a/pkg/report/testdata/linux/report/228 b/pkg/report/testdata/linux/report/228
@@ -0,0 +1,127 @@
+TITLE: KMSAN: uninit-value in ip_route_output_key_hash_rcu
+
+setsockopt$IPT_SO_SET_ADD_COUNTERS(r1, 0x0, 0x41, &(0x7f0000000100)={'filter\x00', 0x3, [{}, {}, {}]}, 0x58)
+getsockopt$netrom_NETROM_T4(0xffffffffffffffff, 0x103, 0x6, &(0x7f00000001c0), &(0x7f0000000200)=0x4)
+
+[  176.992079] ==================================================================
+[  176.999506] BUG: KMSAN: uninit-value in ip_route_output_key_hash_rcu+0x31f0/0x3940
+[  177.007217] CPU: 1 PID: 12207 Comm: syz-executor0 Not tainted 4.16.0+ #81
+[  177.014155] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  177.023519] Call Trace:
+[  177.026109]  dump_stack+0x185/0x1d0
+[  177.029745]  ? ip_route_output_key_hash_rcu+0x31f0/0x3940
+[  177.035283]  kmsan_report+0x142/0x240
+2018/04/06 22:31:14 executing program 6:
+ioctl$DRM_IOCTL_PRIME_HANDLE_TO_FD(0xffffffffffffffff, 0xc00c642d, &(0x7f0000000ff4))
+migrate_pages(0x0, 0x7fff, &(0x7f000000aff8), &(0x7f0000000000))
+
+[  177.039083]  __msan_warning_32+0x6c/0xb0
+[  177.043145]  ip_route_output_key_hash_rcu+0x31f0/0x3940
+[  177.048510]  ? futex_wait_queue_me+0x4ba/0x710
+[  177.053089]  ? rcu_all_qs+0x32/0x1f0
+[  177.056811]  ip_route_output_flow+0x1eb/0x3c0
+[  177.061301]  ? security_sk_classify_flow+0x49/0x190
+[  177.066328]  raw_sendmsg+0x1861/0x3ed0
+[  177.070236]  ? compat_raw_ioctl+0x100/0x100
+[  177.074558]  inet_sendmsg+0x48d/0x740
+[  177.078360]  ? security_socket_sendmsg+0x9e/0x210
+[  177.083206]  ? inet_getname+0x500/0x500
+[  177.087183]  SYSC_sendto+0x6c3/0x7e0
+[  177.090899]  ? __msan_metadata_ptr_for_store_4+0x13/0x20
+[  177.096347]  ? prepare_exit_to_usermode+0x149/0x3a0
+[  177.101374]  SyS_sendto+0x8a/0xb0
+[  177.104827]  do_syscall_64+0x309/0x430
+[  177.108723]  ? SYSC_getpeername+0x560/0x560
+[  177.113057]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
+[  177.118243] RIP: 0033:0x455259
+[  177.121425] RSP: 002b:00007fdc0625dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
+[  177.129128] RAX: ffffffffffffffda RBX: 00007fdc0625e6d4 RCX: 0000000000455259
+2018/04/06 22:31:14 executing program 6:
+r0 = openat$selinux_checkreqprot(0xffffffffffffff9c, &(0x7f0000000000)='/selinux/checkreqprot\x00', 0x0, 0x0)
+r1 = openat$ptmx(0xffffffffffffff9c, &(0x7f0000f40000)='/dev/ptmx\x00', 0x200000000101002, 0x0)
+sendfile(r1, r0, &(0x7f0000001740), 0x8a)
+
+[  177.136386] RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000013
+[  177.143652] RBP: 000000000072bea0 R08: 0000000020000080 R09: 0000000000000010
+[  177.150915] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
+[  177.158181] R13: 00000000000004f7 R14: 00000000006fa7c8 R15: 0000000000000000
+[  177.165446] 
+[  177.167065] Local variable description: ----res.i.i@ip_route_output_flow
+[  177.173892] Variable was created at:
+[  177.177610]  ip_route_output_flow+0x75/0x3c0
+[  177.182016]  raw_sendmsg+0x1861/0x3ed0
+[  177.185896] ==================================================================
+[  177.193260] Disabling lock debugging due to kernel taint
+[  177.198725] Kernel panic - not syncing: panic_on_warn set ...
+[  177.198725] 
+[  177.206091] CPU: 1 PID: 12207 Comm: syz-executor0 Tainted: G    B            4.16.0+ #81
+[  177.214312] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+[  177.223828] Call Trace:
+[  177.226413]  dump_stack+0x185/0x1d0
+[  177.230040]  panic+0x39d/0x940
+[  177.233260]  ? ip_route_output_key_hash_rcu+0x31f0/0x3940
+[  177.238796]  kmsan_report+0x238/0x240
+2018/04/06 22:31:14 executing program 6:
+r0 = syz_open_dev$evdev(&(0x7f0000000000)='/dev/input/event#\x00', 0x2, 0x28001)
+write$evdev(r0, &(0x7f0000037fe8)=[{{}, 0x1, 0x48, 0x2}, {}], 0x30)
+
+[  177.242592]  __msan_warning_32+0x6c/0xb0
+[  177.246653]  ip_route_output_key_hash_rcu+0x31f0/0x3940
+[  177.252017]  ? futex_wait_queue_me+0x4ba/0x710
+[  177.256601]  ? rcu_all_qs+0x32/0x1f0
+[  177.260324]  ip_route_output_flow+0x1eb/0x3c0
+[  177.264817]  ? security_sk_classify_flow+0x49/0x190
+[  177.269836]  raw_sendmsg+0x1861/0x3ed0
+[  177.273743]  ? compat_raw_ioctl+0x100/0x100
+[  177.278064]  inet_sendmsg+0x48d/0x740
+[  177.281864]  ? security_socket_sendmsg+0x9e/0x210
+[  177.286707]  ? inet_getname+0x500/0x500
+[  177.290682]  SYSC_sendto+0x6c3/0x7e0
+[  177.294397]  ? __msan_metadata_ptr_for_store_4+0x13/0x20
+[  177.299841]  ? prepare_exit_to_usermode+0x149/0x3a0
+[  177.304867]  SyS_sendto+0x8a/0xb0
+[  177.308321]  do_syscall_64+0x309/0x430
+[  177.312213]  ? SYSC_getpeername+0x560/0x560
+[  177.316541]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
+[  177.321719] RIP: 0033:0x455259
+[  177.324898] RSP: 002b:00007fdc0625dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
+[  177.332603] RAX: ffffffffffffffda RBX: 00007fdc0625e6d4 RCX: 0000000000455259
+[  177.339867] RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000013
+[  177.347143] RBP: 000000000072bea0 R08: 0000000020000080 R09: 0000000000000010
+[  177.347150] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
+[  177.347158] R13: 00000000000004f7 R14: 00000000006fa7c8 R15: 0000000000000000
+[  177.347607] Dumping ftrace buffer:
+[  177.347612]    (ftrace buffer empty)
+[  177.347616] Kernel Offset: disabled
+[  177.380116] Rebooting in 86400 seconds..
+
+REPORT:
+==================================================================
+BUG: KMSAN: uninit-value in ip_route_output_key_hash_rcu+0x31f0/0x3940
+CPU: 1 PID: 12207 Comm: syz-executor0 Not tainted 4.16.0+ #81
+Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+Call Trace:
+ dump_stack+0x185/0x1d0
+ kmsan_report+0x142/0x240
+ __msan_warning_32+0x6c/0xb0
+ ip_route_output_key_hash_rcu+0x31f0/0x3940
+ ip_route_output_flow+0x1eb/0x3c0
+ raw_sendmsg+0x1861/0x3ed0
+ inet_sendmsg+0x48d/0x740
+ SYSC_sendto+0x6c3/0x7e0
+ SyS_sendto+0x8a/0xb0
+ do_syscall_64+0x309/0x430
+ entry_SYSCALL_64_after_hwframe+0x3d/0xa2
+RIP: 0033:0x455259
+RSP: 002b:00007fdc0625dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
+RAX: ffffffffffffffda RBX: 00007fdc0625e6d4 RCX: 0000000000455259
+RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000013
+RBP: 000000000072bea0 R08: 0000000020000080 R09: 0000000000000010
+R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
+R13: 00000000000004f7 R14: 00000000006fa7c8 R15: 0000000000000000
+
+Local variable description: ----res.i.i@ip_route_output_flow
+Variable was created at:
+ ip_route_output_flow+0x75/0x3c0
+ raw_sendmsg+0x1861/0x3ed0
+==================================================================