Security tracker / CVE-2025-21836

CVE-2025-21836

io_uring/kbuf: reallocate buf lists on upgrade

References

• Debian security tracker
• cve.org
• https://www.youtube.com/watch?v=Ry4eOgLCo90
• https://u1f383.github.io/slides/talks/2025_Hexacon-Deja_Vu_in_Linux_io_uring_Breaking_Memory_Sharing_Again_After_Generations_of_Fixes.pdf

Notes

 carnil> Introduced in 2fcabce2d7d34 ("io_uring: disallow mixed provided buffer group
 carnil> registrations"). Vulnerable versions: 5.19.

Bugs

Status

Branch	Status
upstream	released (6.14-rc3) [8802766324e1f5d414a81ac43365c20142e85603]
6.18-upstream-stable	N/A "Fixed before branching point"
6.17-upstream-stable	N/A "Fixed before branching point"
6.13-upstream-stable	released (6.13.4) [2a5febbef40ce968e295a7aeaa5d5cbd9e3e5ad4]
6.12-upstream-stable	released (6.12.16) [7d0dc28dae836caf7645fef62a10befc624dd17b]
6.6-upstream-stable	released (6.6.79) [146a185f6c05ee263db715f860620606303c4633]
6.1-upstream-stable	needed
5.10-upstream-stable	N/A "Vulnerable code not present"
sid	released (6.12.16-1)
6.12-trixie-security	N/A "Fixed before branching point"
6.1-bookworm-security	needed
5.10-bullseye-security	N/A "Vulnerable code not present"