CVE-2022-49664 tipc: move bc link creation back to tipc_node_create
A race condition in the Linux kernel TIPC module causes a NULL pointer dereference, leading to a system crash when processing broadcast packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49664?
CVE-2022-49664 is a high-severity 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:
tipc: move bc link creation back to tipc_node_create
Shuang Li reported a NULL pointer dereference crash:
[] BUG: kernel NULL pointer dereference, address: 0000000000000068 [] RIP: 0010:tipc_link_is_up+0x5/0x10 [tipc] [] Call Trace: [] <IRQ> [] tipc_bcast_rcv+0xa2/0x190 [tipc] [] tipc_node_bc_rcv+0x8b/0x200 [tipc] [] tipc_rcv+0x3af/0x5b0 [tipc] [] tipc_udp_recv+0xc7/0x1e0 [tipc]
It was caused by the 'l' passed into tipc_bcast_rcv() is NULL. When it creates a node in tipc_node_check_dest(), after inserting the new node into hashtable in tipc_node_create(), it creates the bc link. However, there is a gap between this insert and bc link creation, a bc packet may come in and get the node from the hashtable then try to dereference its bc link, which is NULL.
This patch is to fix it by moving the bc link creation before inserting into the hashtable.
Note that for a preliminary node becoming "real", the bc link creation should also be called before it's rehashed, as we don't create it for preliminary nodes.
Weakness: CWE-476
Which versions are affected by CVE-2022-49664?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49664?
Apply the vendor's patch.
Is CVE-2022-49664 being exploited?
There is no known exploitation of CVE-2022-49664 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49664, GHSA-v579-rch8-988w, UBUNTU-CVE-2022-49664.