Strix
63.7K

CVE-2026-89979

HIGHCVSS 7.8/10

Last modified

CVE-2026-89979 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix race between non-atomic ops and trigger-start We protect the races of the concurrent state transitions between atomic PCM ops, but the checks between the non-atomic ops (hw_params, hw_free and prepare) and the atomic ops aren't perfect; there is a check of the conflicting PCM state at the beginning of hw_params & co, but the atomic PCM ops can be still issued during the non-atomic PCM operations. An example such scenario is that a thread A re-issues the PREPARE or HW_PARAMS for the already prepared stream, while another thread B triggers the PCM start in the middle of the prepare operation.

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix race between non-atomic ops and trigger-start We protect the races of the concurrent state transitions between atomic PCM ops, but the checks between the non-atomic ops (hw_params, hw_free and prepare) and the atomic ops aren't perfect; there is a check of the conflicting PCM state at the beginning of hw_params & co, but the atomic PCM ops can be still issued during the non-atomic PCM operations. An example such scenario is that a thread A re-issues the PREPARE or HW_PARAMS for the already prepared stream, while another thread B triggers the PCM start in the middle of the prepare operation. Although this usually doesn't lead to much serious issues, it can give some inconsistency as reported by syzkaller (such as ODEBUG warning). There are various atomic PCM ops, and basically the only problem is the PCM start as it operates from the PREPARED state. Other trigger commands (stop, etc) are for the running or the other special state, hence they are filtered as pre-condition. This patch is for preventing the PCM trigger-start during the non- atomic operations in order to address the problems above. Fortunately, the hw_params, hw_free and prepare operations call snd_pcm_buffer_access_lock(), and this can be used for checking the concurrent operations at the PCM trigger -- which sets the runtime->buffer_accessing to a negative (if possible), so the PCM trigger just needs to check the runtime->buffer_accessing value; if it's negative, it means the concurrent non-atomic PCM ops is running.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < b1d12144557fceed5de6e22e2c2e30a40ed37702; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < b2edc017f94c08bdd0b046a586e43ac771a2f942; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < b599e7f16441386754ec083fa62a549bccb02fca; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < ad29779736cfd6f5595f0cab300dd7611418e363; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 5abeb4f9f2023f001d693b4e5e1ebbf25e25d0eb; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7ad2ea7c10044b08ecf7b04376916faf12e17a99; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 50afadf1ea66597116eb14e73c24da7ae99b759f; >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < acac7b5e07349a9d10d78873afb4b93cd1dc721f
LinuxLinux2.6.12

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-89979?
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix race between non-atomic ops and trigger-start We protect the races of the concurrent state transitions between atomic PCM ops, but the checks between the non-atomic ops (hw_params, hw_free and prepare) and the atomic ops aren't perfect; there is a check of the conflicting PCM state at the beginning of hw_params & co, but the atomic PCM ops can be still issued during the non-atomic PCM operations. An example such scenario is that a thread A re-issues the PREPARE or HW_PARAMS for the already prepared stream, while another thread B triggers the PCM start in the middle of the prepare operation. Although this usually doesn't lead to much serious issues, it can give some inconsistency as reported by syzkaller (such as ODEBUG warning). There are various atomic PCM ops, and basically the only problem is the PCM start as it operates from the PREPARED state. Other trigger commands (stop, etc) are for the running or the other special state, hence they are filtered as pre-condition. This patch is for preventing the PCM trigger-start during the non- atomic operations in order to address the problems above. Fortunately, the hw_params, hw_free and prepare operations call snd_pcm_buffer_access_lock(), and this can be used for checking the concurrent operations at the PCM trigger -- which sets the runtime->buffer_accessing to a negative (if possible), so the PCM trigger just needs to check the runtime->buffer_accessing value; if it's negative, it means the concurrent non-atomic PCM ops is running.
How severe is CVE-2026-89979?
CVE-2026-89979 has a CVSS score of 7.8/10 (HIGH severity).
How do I fix CVE-2026-89979?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →

Are you affected by CVE-2026-89979?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST