CVE-2025-21837

Name	CVE-2025-21837
Description	In the Linux kernel, the following vulnerability has been resolved: io_uring/uring_cmd: unconditionally copy SQEs at prep time This isn't generally necessary, but conditions have been observed where SQE data is accessed from the original SQE after prep has been done and outside of the initial issue. Opcode prep handlers must ensure that any SQE related data is stable beyond the prep phase, but uring_cmd is a bit special in how it handles the SQE which makes it susceptible to reading stale data. If the application has reused the SQE before the original completes, then that can lead to data corruption. Down the line we can relax this again once uring_cmd has been sanitized a bit, and avoid unnecessarily copying the SQE.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.234-1	fixed
	bookworm	6.1.129-1	fixed
	bookworm (security)	6.1.133-1	fixed
	trixie	6.12.21-1	vulnerable
	sid	6.12.22-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
linux	source	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	(unstable)	(unfixed)

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/d6211ebbdaa541af197b50b8dd8f22642ce0b87f (6.14-rc3)