CVE-2026-53388fuse: re-lock request before replacing page cache folio

Official description

In the Linux kernel, the following vulnerability has been resolved: fuse: re-lock request before replacing page cache folio fuse_try_move_folio() unlocks the request on entry but does not re-lock it on the success path. This means fuse_chan_abort() can end the request and free the fuse_io_args (eg fuse_readpages_end()) while the subsequent copy chain logic after fuse_try_move_folio() accesses the fuse_io_args, leading to use-after-free issues. Fix this by calling lock_request() before replace_page_cache_folio(). This ensures the request is locked on the success path which will prevent the fuse_io_args from being freed while the later copying logic runs, and also ensures that the ap->folios[i]->mapping is never null since ap->folios[i] will always point to the newfolio after replace_page_cache_folio().

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/7c18691e0cfda29672f79bafde8abdb7710674f6
• https://git.kernel.org/stable/c/5927b43a4f8d89e86930f524bf63e9c7e66f61b4
• https://git.kernel.org/stable/c/030fe3e9d8abdee303dd7e9e42f45082d382a407
• https://git.kernel.org/stable/c/46473ddccdc5065033e397d6e62c280dbcd3d9c2
• https://git.kernel.org/stable/c/af2892249d982a1c036ca456cc135374e68b6677
• https://git.kernel.org/stable/c/0223f452532d9cd8a5e87c45de828fd93c99bd25
• https://git.kernel.org/stable/c/e28db6ac4792d065ab32565fd9f0a2361c3d4666
• https://git.kernel.org/stable/c/a078484921052d0badd827fcc2770b5cfc1d4120