CVE-2025-39792 Affecting kernel6.12-devel package, versions <1:6.12.46-66.121.amzn2023
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-AMZN2023-KERNEL612DEVEL-13170841
- published1 Oct 2025
- disclosed12 Sept 2025
Introduced: 12 Sep 2025
NewCVE-2025-39792 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2023 kernel6.12-devel to version 1:6.12.46-66.121.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1208.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel6.12-devel package and not the kernel6.12-devel package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
dm: Always split write BIOs to zoned device limits
Any zoned DM target that requires zone append emulation will use the block layer zone write plugging. In such case, DM target drivers must not split BIOs using dm_accept_partial_bio() as doing so can potentially lead to deadlocks with queue freeze operations. Regular write operations used to emulate zone append operations also cannot be split by the target driver as that would result in an invalid writen sector value return using the BIO sector.
In order for zoned DM target drivers to avoid such incorrect BIO splitting, we must ensure that large BIOs are split before being passed to the map() function of the target, thus guaranteeing that the limits for the mapped device are not exceeded.
dm-crypt and dm-flakey are the only target drivers supporting zoned devices and using dm_accept_partial_bio().
In the case of dm-crypt, this function is used to split BIOs to the internal max_write_size limit (which will be suppressed in a different patch). However, since crypt_alloc_buffer() uses a bioset allowing only up to BIO_MAX_VECS (256) vectors in a BIO. The dm-crypt device max_segments limit, which is not set and so default to BLK_MAX_SEGMENTS (128), must thus be respected and write BIOs split accordingly.
In the case of dm-flakey, since zone append emulation is not required, the block layer zone write plugging is not used and no splitting of BIOs required.
Modify the function dm_zone_bio_needs_split() to use the block layer helper function bio_needs_zone_write_plugging() to force a call to bio_split_to_limits() in dm_split_and_process_bio(). This allows DM target drivers to avoid using dm_accept_partial_bio() for write operations on zoned DM devices.
References
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-39792
- https://git.kernel.org/stable/c/2df7168717b7d2d32bcf017c68be16e4aae9dd13
- https://git.kernel.org/stable/c/4e9fef1cf0243d665d75c371cc80be6156cd30a2
- https://git.kernel.org/stable/c/d10bf66d9f9335ffc7521b3029b114f50604cabe
- https://git.kernel.org/stable/c/f5dd256333c08ab44b5aec4a8118cb04c0f20c54