fuse: re-lock request before returning from fuse_ref_folio()

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before returning from fuse_ref_folio() fuse_ref_folio() unlocks the request but does not re-lock it before returning. fuse_chan_abort() can end the request and the async end callback (eg fuse_writepage_free()) can free the args while the subsequent copy chain logic after fuse_ref_folio() accesses them, leading to use-after-free issues. Fix this by locking the request in fuse_ref_folio() before returning.

Timeline

1. Jul 25, 2026, 8:49 AM UTCCVE published
2. Oct 16, 2026, 3:38 PM UTCCISA SSVC assessment

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

3. Oct 19, 2026, 8:28 PM UTCRecord last updated

Affected versions

• Linux Linux

  From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in 1f9156714592356b4fda57beac7eab9c2a462dd3; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in 5630da218a45ba80f0aba0846cbe8aa655da122b; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in 1ca605cfa59377f0143fb35b5b01360f37d1b7c4; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in 0e4a5a000123d81234e27a2f8187688cf608f755; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in e6aa539720c3d8def69683ed0c07cf9faea4e8be; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in be353caffa8640f5e25fb3714ce8b0cef5e410e5; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in 65a1c2551f7e16085acbb54aedde1feaa559ba7a; From c3021629a0d820247ee12b6c5192a1d5380e21c6 · fixed in b5befa80fdbe287a98480effed9564712924add5

• Linux Linux

  2.6.35

• KernelLinux

  From 2.6.35 · fixed in 5.10.261; From 5.11.0 · fixed in 5.15.212; From 5.16.0 · fixed in 6.1.178; From 6.2.0 · fixed in 6.6.145; From 6.7.0 · fixed in 6.12.96; From 6.13.0 · fixed in 6.18.39; From 6.19.0 · fixed in 7.1.4

References 8