From 843c4cfcf445fc3d6458ff31136c44e03dda8866 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Wed, 22 Apr 2020 15:07:13 +0200 Subject: [PATCH] virtio-net: Fix duplex=... and speed=... error handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit virtio_net_device_realize() rejects invalid duplex and speed values. The error handling is broken: $ ../qemu/bld-sani/x86_64-softmmu/qemu-system-x86_64 -S -display none -monitor stdio QEMU 4.2.93 monitor - type 'help' for more information (qemu) device_add virtio-net,duplex=x Error: 'duplex' must be 'half' or 'full' (qemu) c ================================================================= ==15654==ERROR: AddressSanitizer: heap-use-after-free on address 0x62e000014590 at pc 0x560b75c8dc13 bp 0x7fffdf1a6950 sp 0x7fffdf1a6940 READ of size 8 at 0x62e000014590 thread T0 #0 0x560b75c8dc12 in object_dynamic_cast_assert /work/armbru/qemu/qom/object.c:826 #1 0x560b74c38ac0 in virtio_vmstate_change /work/armbru/qemu/hw/virtio/virtio.c:3210 #2 0x560b74d9765e in vm_state_notify /work/armbru/qemu/softmmu/vl.c:1271 #3 0x560b7494ba72 in vm_prepare_start /work/armbru/qemu/cpus.c:2156 #4 0x560b7494bacd in vm_start /work/armbru/qemu/cpus.c:2162 #5 0x560b75a7d890 in qmp_cont /work/armbru/qemu/monitor/qmp-cmds.c:160 #6 0x560b75a8d70a in hmp_cont /work/armbru/qemu/monitor/hmp-cmds.c:1043 #7 0x560b75a799f2 in handle_hmp_command /work/armbru/qemu/monitor/hmp.c:1082 [...] 0x62e000014590 is located 33168 bytes inside of 42288-byte region [0x62e00000c400,0x62e000016930) freed by thread T1 here: #0 0x7feadd39491f in __interceptor_free (/lib64/libasan.so.5+0x10d91f) #1 0x7feadcebcd7c in g_free (/lib64/libglib-2.0.so.0+0x55d7c) #2 0x560b75c8fd40 in object_unref /work/armbru/qemu/qom/object.c:1128 #3 0x560b7498a625 in memory_region_unref /work/armbru/qemu/memory.c:1762 #4 0x560b74999fa4 in do_address_space_destroy /work/armbru/qemu/memory.c:2788 #5 0x560b762362fc in call_rcu_thread /work/armbru/qemu/util/rcu.c:283 #6 0x560b761c8884 in qemu_thread_start /work/armbru/qemu/util/qemu-thread-posix.c:519 #7 0x7fead9be34bf in start_thread (/lib64/libpthread.so.0+0x84bf) previously allocated by thread T0 here: #0 0x7feadd394d18 in __interceptor_malloc (/lib64/libasan.so.5+0x10dd18) #1 0x7feadcebcc88 in g_malloc (/lib64/libglib-2.0.so.0+0x55c88) #2 0x560b75c8cf8a in object_new /work/armbru/qemu/qom/object.c:699 #3 0x560b75010ad9 in qdev_device_add /work/armbru/qemu/qdev-monitor.c:654 #4 0x560b750120c2 in qmp_device_add /work/armbru/qemu/qdev-monitor.c:805 #5 0x560b75012c1b in hmp_device_add /work/armbru/qemu/qdev-monitor.c:905 [...] ==15654==ABORTING Cause: virtio_net_device_realize() neglects to bail out after setting the error. Fix that. Fixes: 9473939ed7addcaaeb8fde5c093918fb7fa0919c Cc: "Michael S. Tsirkin" Cc: Jason Wang Signed-off-by: Markus Armbruster Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20200422130719.28225-9-armbru@redhat.com> Acked-by: Michael S. Tsirkin --- hw/net/virtio-net.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index eddfa7f923f9..65bb6886c750 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -2947,6 +2947,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) n->net_conf.duplex = DUPLEX_FULL; } else { error_setg(errp, "'duplex' must be 'half' or 'full'"); + return; } n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX); } else { @@ -2955,7 +2956,9 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) if (n->net_conf.speed < SPEED_UNKNOWN) { error_setg(errp, "'speed' must be between 0 and INT_MAX"); - } else if (n->net_conf.speed >= 0) { + return; + } + if (n->net_conf.speed >= 0) { n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX); }