CVE-2025-37805
sound/virtio: Fix cancel_sync warnings on uninitialized work_structs
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sound/virtio: Fix cancel_sync warnings on uninitialized work_structs
In the Linux kernel, the following vulnerability has been resolved: sound/virtio: Fix cancel_sync warnings on uninitialized work_structs Betty reported hitting the following warning: [ 8.709131][ T221] WARNING: CPU: 2 PID: 221 at kernel/workqueue.c:4182 ... [ 8.713282][ T221] Call trace: [ 8.713365][ T221] __flush_work+0x8d0/0x914 [ 8.713468][ T221] __cancel_work_sync+0xac/0xfc [ 8.713570][ T221] cancel_work_sync+0x24/0x34 [ 8.713667][ T221] virtsnd_remove+0xa8/0xf8 [virtio_snd ab15f34d0dd772f6d11327e08a81d46dc9c36276] [ 8.713868][ T221] virtsnd_probe+0x48c/0x664 [virtio_snd ab15f34d0dd772f6d11327e08a81d46dc9c36276] [ 8.714035][ T221] virtio_dev_probe+0x28c/0x390 [ 8.714139][ T221] really_probe+0x1bc/0x4c8 ... It seems we're hitting the error path in virtsnd_probe(), which triggers a virtsnd_remove() which iterates over the substreams calling cancel_work_sync() on the elapsed_period work_struct. Looking at the code, from earlier in: virtsnd_probe()->virtsnd_build_devs()->virtsnd_pcm_parse_cfg() We set snd->nsubstreams, allocate the snd->substreams, and if we then hit an error on the info allocation or something in virtsnd_ctl_query_info() fails, we will exit without having initialized the elapsed_period work_struct. When that error path unwinds we then call virtsnd_remove() which as long as the substreams array is allocated, will iterate through calling cancel_work_sync() on the uninitialized work struct hitting this warning. Takashi Iwai suggested this fix, which initializes the substreams structure right after allocation, so that if we hit the error paths we avoid trying to cleanup uninitialized data. Note: I have not yet managed to reproduce the issue myself, so this patch has had limited testing. Feedback or thoughts would be appreciated!
Reserved 2025-04-16 | Published 2025-05-08 | Updated 2025-05-12 | Assigner Linuxgit.kernel.org/...c/e03b10c45c7675b6098190c6e7de1b656d8bcdbe
git.kernel.org/...c/54c7b864fbe4423a07b443a4ada0106052942116
git.kernel.org/...c/5be9407b41eae20eef9140f5cfbfcbc3d01aaf45
git.kernel.org/...c/66046b586c0aaa9332483bcdbd76e3305d6138e9
git.kernel.org/...c/9908498ce929a5a052b79bb7942f9ea317312ce4
git.kernel.org/...c/3c7df2e27346eb40a0e86230db1ccab195c97cfe
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