CVE-2026-98443 PUBLISHED

xfs: fix cursor and pointer handling when recovering iunlink buckets

Assigner: Linux
Reserved: 25.09.2026 Published: 18.10.2026 Updated: 18.10.2026

In the Linux kernel, the following vulnerability has been resolved:

xfs: fix cursor and pointer handling when recovering iunlink buckets

LOLLM pointed out a bug in xlog_recover_iunlink_bucket:

  1. We don't null out prev_ip after releasing it, which can lead to UAF problems if the inodegc flush call in the loop fails.

at which point I noticed even more bugs:

  1. If the inodegc flush inside the loop fails, we also leak @ip.

  2. We set prev_agino to agino having already advanced agino, which results in inodes with i_prev_unlinked set to itself.

  3. If we exit the bottom of the loop with prev_ip set, then prev_ip aliases ip and we also set its i_prev_unlinked to itself.

Bugs 3 and 4 introduce loops into the unlinked list, though these loops don't surface because we immediately flush each unlinked inode after loading it.

Fix all of these issues.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 04755d2e5821b3afbaadd09fe5df58d04de36484 to 8c9d5b8a96d6b93eb24e07b4163c89341ba29bd1 (excl.)
  • affected from 04755d2e5821b3afbaadd09fe5df58d04de36484 to 66a2179d02668f8df44b1a249899006f3ba38ea0 (excl.)
  • affected from 04755d2e5821b3afbaadd09fe5df58d04de36484 to 961c717e6bf0e53c2c2b1fe4aef1add9390fedab (excl.)
  • affected from 04755d2e5821b3afbaadd09fe5df58d04de36484 to 65f39d09d73718611cee40399179323b5d4ead00 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.0 is affected
  • unaffected from 0 to 6.0 (excl.)
  • unaffected from 6.12.113 to 6.12.* (incl.)
  • unaffected from 6.18.55 to 6.18.* (incl.)
  • unaffected from 7.2.9 to 7.2.* (incl.)
  • unaffected from 7.3-rc5 to * (incl.)

References