CVE-2025-37805: Linux kernel · sound/virtio: Fix cancel_sync warnings on uninitialized work_structs
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1088.95~20.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:14 UTC
- Patch
- Available – fixed in 5.15.0-1088.95~20.04.1, 5.15.0-1094.103~20.04.1, 5.15.0-1114.123~20.04.1 +61
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7655-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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!
References
- ubuntu.com/security/CVE-2025-37805 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37805 (opens in a new tab)
- git.kernel.org/linus/3c7df2e27346eb40a0e86230db1ccab195c97cfe (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7655-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7654-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-3 (opens in a new tab)