CVE-2026-99172
In the Linux kernel, the following vulnerability has been resolved: ipc: drop the mqueue mount with kern_unmount() on setup failure mq_init_ns() creates the mqueue mount with fc_mount_longterm(), so its ->mnt_ns is MNT_NS_INTERNAL. When setting up the mqueue or ipc sysctls or msg_init_ns() fails afterwards, create_ipc_ns() drops it with a plain mntput(). With ->mnt_ns set that takes the fast path of mntput_no_expire(). The count drops to zero and nothing ever kills the mount, so the mount and the mqueue superblock are leaked. Commit dc55e35f9e81 ("ipc: Store mqueue sysctls in the ipc namespace") added the first failure path after mq_init_ns() and never dropped the mount. Commit 7229d74e5e8c ("ipc: create_ipc_ns: drop mqueue mount on sysctl setup failure") tried to fix that with a mntput() but that doesn't help for a long-term mount. Use kern_unmount(). free_ipc() open-codes the same thing for a namespace that made it.
- Status
- Received - 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- Published
- 2026-10-28
- Last modified
- 2026-10-28
Affected products
References
- https://git.kernel.org/stable/c/c0620b648321fff654173d238d4a85298ea16d05
- https://git.kernel.org/stable/c/f0e48172a59e517e613b73f73cc35f24fd123aeb
