CVE-2026-68149

Technical Description

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

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References