CVE-2022-49418 NFSv4: Fix free of uninitialized nfs4_label on referral lookup.
A use-after-free vulnerability in the Linux kernel NFSv4 module allows local attackers to cause a system crash via referral lookup.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49418?
CVE-2022-49418 is a critical use after free vulnerability in Linux kernel, published on 26 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix free of uninitialized nfs4_label on referral lookup.
Send along the already-allocated fattr along with nfs4_fs_locations, and drop the memcpy of fattr. We end up growing two more allocations, but this fixes up a crash as:
PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls" #0 [ffffc90000857920] panic at ffffffff81b9bfde #1 [ffffc900008579c0] do_trap at ffffffff81023a9b #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs] #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f #7 [ffffc90000857c60] walk_component at ffffffff813a86c4 #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553 #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b
Weakness: CWE-908
Which versions are affected by CVE-2022-49418?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49418?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2022-49418 being exploited?
There is no known exploitation of CVE-2022-49418 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49418, GHSA-cmjx-92rg-pwqx, UBUNTU-CVE-2022-49418.