CVE-2022-50076 cifs: Fix memory leak on the deferred close
A memory leak in the Linux kernel CIFS module allows attackers to cause denial of service by exhausting kernel memory through deferred close operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50076?
CVE-2022-50076 is a medium-severity denial of service vulnerability in Linux kernel, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix memory leak on the deferred close
xfstests on smb21 report kmemleak as below:
unreferenced object 0xffff8881767d6200 (size 64): comm "xfs_io", pid 1284, jiffies 4294777434 (age 20.789s) hex dump (first 32 bytes): 80 5a d0 11 81 88 ff ff 78 8a aa 63 81 88 ff ff .Z......x..c.... 00 71 99 76 81 88 ff ff 00 00 00 00 00 00 00 00 .q.v............ backtrace: [<00000000ad04e6ea>] cifs_close+0x92/0x2c0 [<0000000028b93c82>] __fput+0xff/0x3f0 [<00000000d8116851>] task_work_run+0x85/0xc0 [<0000000027e14f9e>] do_exit+0x5e5/0x1240 [<00000000fb492b95>] do_group_exit+0x58/0xe0 [<00000000129a32d9>] __x64_sys_exit_group+0x28/0x30 [<00000000e3f7d8e9>] do_syscall_64+0x35/0x80 [<00000000102e8a0b>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
When cancel the deferred close work, we should also cleanup the struct cifs_deferred_close.
Weakness: CWE-401
Which versions are affected by CVE-2022-50076?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50076?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-50076 being exploited?
There is no known exploitation of CVE-2022-50076 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50076, GHSA-hc4h-pg37-34f7, UBUNTU-CVE-2022-50076.