CVE-2022-49295 nbd: call genl_unregister_family() first in nbd_cleanup()
A race condition in the Linux kernel NBD module cleanup can cause a NULL pointer dereference and system crash.
- 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-2022-49295?
CVE-2022-49295 is a high-severity vulnerability in Linux kernel, published on 26 Feb 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:
nbd: call genl_unregister_family() first in nbd_cleanup()
Otherwise there may be race between module removal and the handling of netlink command, which can lead to the oops as shown below:
BUG: kernel NULL pointer dereference, address: 0000000000000098 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 31299 Comm: nbd-client Tainted: G E 5.14.0-rc4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:down_write+0x1a/0x50 Call Trace: start_creating+0x89/0x130 debugfs_create_dir+0x1b/0x130 nbd_start_device+0x13d/0x390 [nbd] nbd_genl_connect+0x42f/0x748 [nbd] genl_family_rcv_msg_doit.isra.0+0xec/0x150 genl_rcv_msg+0xe5/0x1e0 netlink_rcv_skb+0x55/0x100 genl_rcv+0x29/0x40 netlink_unicast+0x1a8/0x250 netlink_sendmsg+0x21b/0x430 ____sys_sendmsg+0x2a4/0x2d0 ___sys_sendmsg+0x81/0xc0 __sys_sendmsg+0x62/0xb0 __x64_sys_sendmsg+0x1f/0x30 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae Modules linked in: nbd(E-)
Weakness: CWE-476
Which versions are affected by CVE-2022-49295?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49295?
Apply the vendor's patch.
Is CVE-2022-49295 being exploited?
There is no known exploitation of CVE-2022-49295 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49295, GHSA-r864-6v77-6j77, UBUNTU-CVE-2022-49295.