Out-of-bounds Write Affecting linux-qemu-rc package, versions <7.1_rc3-r0
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.
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Test your applications- Snyk IDSNYK-CHAINGUARDLATEST-LINUXQEMURC-16727792
- published17 May 2026
- disclosed1 May 2026
Introduced: 1 May 2026
CVE-2026-31716 (opens in a new tab)How to fix?
Upgrade Chainguard linux-qemu-rc to version 7.1_rc3-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream linux-qemu-rc package and not the linux-qemu-rc package as distributed by Chainguard.
See How to fix? for Chainguard relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: validate rec->used in journal-replay file record check
check_file_record() validates rec->total against the record size but never validates rec->used. The do_action() journal-replay handlers read rec->used from disk and use it to compute memmove lengths:
DeleteAttribute: memmove(attr, ..., used - asize - roff) CreateAttribute: memmove(..., attr, used - roff) change_attr_size: memmove(..., used - PtrOffset(rec, next))
When rec->used is smaller than the offset of a validated attribute, or larger than the record size, these subtractions can underflow allowing us to copy huge amounts of memory in to a 4kb buffer, generally considered a bad idea overall.
This requires a corrupted filesystem, which isn't a threat model the kernel really needs to worry about, but checking for such an obvious out-of-bounds value is good to keep things robust, especially on journal replay
Fix this up by bounding rec->used correctly.
This is much like commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") which checked different values in this same switch statement.
References
- https://git.kernel.org/stable/c/0112e6279420d4005b3d57af36fb45c01b8d0116
- https://git.kernel.org/stable/c/0ca0485e4b2e837ebb6cbd4f2451aba665a03e4b
- https://git.kernel.org/stable/c/4b1613d7e2deda831a97e427d1ea586e50fe1be5
- https://git.kernel.org/stable/c/f79d0403ea20a81bc29105bba54fbcab54e8c403
- https://git.kernel.org/stable/c/f90b8a1798b750755a9e9aee66678f0a1820bbaf
- https://git.kernel.org/stable/c/1393a467a9607e62123806de7d4c3a3e54e396a9
- https://git.kernel.org/stable/c/8e64d33198b5a0fb14a452708bad844f94f03b2c