Description
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!
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
29b96bf50ba958eb5f097cdc3fbd4c1acf9547a2 to < e03b10c45c7675b6098190c6e7de1b656d8bcdbeaffected29b96bf50ba958eb5f097cdc3fbd4c1acf9547a2 to < 54c7b864fbe4423a07b443a4ada0106052942116affected29b96bf50ba958eb5f097cdc3fbd4c1acf9547a2 to < 5be9407b41eae20eef9140f5cfbfcbc3d01aaf45affected29b96bf50ba958eb5f097cdc3fbd4c1acf9547a2 to < 66046b586c0aaa9332483bcdbd76e3305d6138e9affected29b96bf50ba958eb5f097cdc3fbd4c1acf9547a2 to < 9908498ce929a5a052b79bb7942f9ea317312ce4affected29b96bf50ba958eb5f097cdc3fbd4c1acf9547a2 to < 3c7df2e27346eb40a0e86230db1ccab195c97cfeaffected
Linux Linux
Default version status: affected
5.13affected0 to < 5.13unaffected5.15.181 to ≤ 5.15.*unaffected6.1.136 to ≤ 6.1.*unaffected6.6.89 to ≤ 6.6.*unaffected6.12.26 to ≤ 6.12.*unaffected6.14.5 to ≤ 6.14.*unaffected6.15 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/e03b10c45c7675b6098190c6e7de1b656d8bcdbe ↗
- https://git.kernel.org/stable/c/54c7b864fbe4423a07b443a4ada0106052942116 ↗
- https://git.kernel.org/stable/c/5be9407b41eae20eef9140f5cfbfcbc3d01aaf45 ↗
- https://git.kernel.org/stable/c/66046b586c0aaa9332483bcdbd76e3305d6138e9 ↗
- https://git.kernel.org/stable/c/9908498ce929a5a052b79bb7942f9ea317312ce4 ↗
- https://git.kernel.org/stable/c/3c7df2e27346eb40a0e86230db1ccab195c97cfe ↗
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html ↗