fuse: reject fuse_notify() pagecache ops on directories

Summary

In the Linux kernel, the following vulnerability has been resolved: fuse: reject fuse_notify() pagecache ops on directories The operations FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE allow the FUSE daemon to actively write/read pagecache contents. For directories with FOPEN_CACHE_DIR, the pagecache is used as kernel-internal cache storage, and userspace is not supposed to have direct access to this cache - in particular, fuse_parse_cache() will hit WARN_ON() if the cache contains bogus data. Reject FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE on anything other than regular files with -EINVAL.

Timeline

1. Jun 25, 2026, 8:38 AM UTCCVE published
2. Oct 15, 2026, 1:22 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in 15487f98863dc7156ed43c5be26d478beb82ba35; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in bd23fa0c16c5c86e5b7713224ffbb87d9db81cca; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in 9dbf1b2fadfc6c40805631d8a8276d1639fc9ab6; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in dd92773d4d9cea010474eb08a5133c14ff6ab53a; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in 99c317d7f8b7bbf3de16d20a01f363e390114cea; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in 12df4cfa738aefff21756728e91056d7defb0fe6; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in e692f0cb86204dcdb9dddc0b355407eda6394a67; From 5d7bc7e8680c7ca4c8a4f139ce2a54ccb8131ef0 · fixed in 9c954499d43aefac01c5dfb57a82b13d2dcf4b94

• Linux Linux

  4.20

• KernelLinux

  From 4.20.0 · fixed in 5.10.259; From 5.11.0 · fixed in 5.15.210; From 5.16.0 · fixed in 6.1.176; From 6.2.0 · fixed in 6.6.143; From 6.7.0 · fixed in 6.12.94; From 6.13.0 · fixed in 6.18.36; From 6.19.0 · fixed in 7.0.13

References 8