CVE-2026-68149

Status: UPDATED  |  Advisory ID: CVE-2026-68149

Key Details

Affected Products, Subsystems & Sectors

What to Know

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

fs: preserve ACL_DONT_CACHE state in forget_cached_acl()

The ACL_DONT_CACHE state is meant to be a constant state for the inode

for filesystems that want to opt out of posix acl caching.

Commit facd61053cff1 ("fuse: fixes after adapting to new posix acl api")

used this facility to opt out of posix acl caching for fuse inodes with

fuse server that does not negotiate FUSE_POSIX_ACL (fc->posix_acl).

The commit also takes care to gate the forget_all_cached_acls() call in

fuse_set_acl() on fc->posix_acl because there is no need for it, but

there are other placed in fuse code which call forget_all_cached_acls()

unconditional to fc->posix_acl and those cause the loss of the

ACL_DONT_CACHE state.

This is not only a functional bug. Properly timed, a get_acl() from this

fuse filesystem can return a stale cached value, as was observed in tests,

because set_acl() does not invalidate the unintentional acl cache.

We could fix this in fuse, but it actually makes no sense for the vfs

helper forget_cached_acl() to invalidate the ACL_DONT_CACHE state, so

let it not do that to fix fuse and future users of ACL_DONT_CACHE. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References