Description
In the Linux kernel, the following vulnerability has been resolved: fs/buffer: add alert in try_to_free_buffers() for folios without buffers try_to_free_buffers() can be called on folios with no buffers attached when filemap_release_folio() is invoked on a folio belonging to a mapping with AS_RELEASE_ALWAYS set but no release_folio operation defined. In such cases, folio_needs_release() returns true because of the AS_RELEASE_ALWAYS flag, but the folio has no private buffer data. This causes try_to_free_buffers() to call drop_buffers() on a folio with no buffers, leading to a null pointer dereference. Adding a check in try_to_free_buffers() to return early if the folio has no buffers attached, with WARN_ON_ONCE() to alert about the misconfiguration. This provides defensive hardening.
Product status
d0eafc763135508be118dac208887a26c0adb74d (git) before 1b111a69a6e33a922622bf9870e4e63fb2b649c8
b4fa966f03b7401ceacd4ffd7227197afb2b8376 (git) before c1b6227555c52781178132b7a06466711855795c
b4fa966f03b7401ceacd4ffd7227197afb2b8376 (git) before 727e5140e0cf83b4ce6a11b89bb73bff5d96f8f3
b4fa966f03b7401ceacd4ffd7227197afb2b8376 (git) before 42c32d7571ccd8ef32351cac506f00b0fae99fd2
b4fa966f03b7401ceacd4ffd7227197afb2b8376 (git) before c6246ca15999053d2632fbcc7b86e6eef7f077cb
b4fa966f03b7401ceacd4ffd7227197afb2b8376 (git) before b68f91ef3b3fe82ad78c417de71b675699a8467c
6.6
Any version before 6.6
6.1.165 (semver)
6.6.128 (semver)
6.12.75 (semver)
6.18.16 (semver)
6.19.6 (semver)
7.0 (original_commit_for_fix)
References
git.kernel.org/...c/1b111a69a6e33a922622bf9870e4e63fb2b649c8
git.kernel.org/...c/c1b6227555c52781178132b7a06466711855795c
git.kernel.org/...c/727e5140e0cf83b4ce6a11b89bb73bff5d96f8f3
git.kernel.org/...c/42c32d7571ccd8ef32351cac506f00b0fae99fd2
git.kernel.org/...c/c6246ca15999053d2632fbcc7b86e6eef7f077cb
git.kernel.org/...c/b68f91ef3b3fe82ad78c417de71b675699a8467c