Microsoft security update for CVE-2025-37805 — azl3 kernel
🔗 CVE IDs covered (1)
📋 Microsoft's advisory
EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-37805. This page also shows what EchelonGraph holds for CVE-2025-37805, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.
🎯 Affected products2
- azl3 kernel 6.6.85.1-4 on Azure Linux 3.0
- azl3 kernel 6.6.92.2-1 on Azure Linux 3.0
✅ Updates Microsoft lists: 1 update
1 row: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.
| KB article | Update | Fixed build |
|---|---|---|
| — | Security Update | 6.6.92.2-1 |
🧭 EchelonGraph on CVE-2025-37805
- EchelonGraph score
- 5.5 MEDIUM
- CISA KEV
- Not listed
- Fix status
- A fix is available — apply it.
Description from the CVE record (CVE.org), as published by its numbering authority
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!
Published by kernel.org, the CVE Numbering Authority that assigned CVE-2025-37805, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).