io_uring/kbuf: check if target buffer list is still legacy on recycle

Summary

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: check if target buffer list is still legacy on recycle There's a gap between when the buffer was grabbed and when it potentially gets recycled, where if the list is empty, someone could've upgraded it to a ring provided type. This can happen if the request is forced via io-wq. The legacy recycling is missing checking if the buffer_list still exists, and if it's of the correct type. Add those checks.

Timeline

1. May 8, 2026, 2:21 PM UTCCVE published
2. Oct 16, 2026, 3:16 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 19, 2026, 7:16 PM UTCRecord last updated

Affected versions

• Linux Linux

  From c7fb19428d67dd0a2a78a4f237af01d39c78dc5a · fixed in a7b33671e418fca507feebd1d56e7f4952a4b25c; From c7fb19428d67dd0a2a78a4f237af01d39c78dc5a · fixed in 439a6728ec4641ffad1ca796622c19bc525e570f; From c7fb19428d67dd0a2a78a4f237af01d39c78dc5a · fixed in f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa; From c7fb19428d67dd0a2a78a4f237af01d39c78dc5a · fixed in 50ad880db3013c6fee0ef13781762a39e2e7ef83; From c7fb19428d67dd0a2a78a4f237af01d39c78dc5a · fixed in 97b57f69fee1b61b41acbf37e7720cac9d389fa4; From c7fb19428d67dd0a2a78a4f237af01d39c78dc5a · fixed in c2c185be5c85d37215397c8e8781abf0a69bec1f

• Linux Linux

  5.19

• KernelLinux

  From 5.19.0 · fixed in 6.1.167; From 6.2.0 · fixed in 6.6.130; From 6.7.0 · fixed in 6.12.78; From 6.13.0 · fixed in 6.18.19; From 6.19.0 · fixed in 6.19.9

References 6