ipc/shm: serialize orphan cleanup with shm_nattch updates
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.1%
exploitation probability
0.1%top 98% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
ipc/shm: serialize orphan cleanup with shm_nattch updates
shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that
does not serialize all fields tested by shm_may_destroy(). In particular,
shm_nattch is updated while holding shm_perm.lock, and attach paths can do
that without holding the rwsem.
Do not decide that an orphaned segment is unused before taking the object
lock. Move the shm_may_destroy() check under shm_perm.lock, matching the
other destroy paths, and unlock the segment when it no longer qualifies
for removal.
Affected products
Linux · LinuxReferences
https://git.kernel.org/stable/c/030bbc857bd51d4b25a90d931d3f8775ef22823ahttps://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbebhttps://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c