Executive brief
A vulnerability in the Linux kernel's networking component could allow a remote attacker to crash the system. The issue occurs when specific types of network sockets are opened but not fully initialized before receiving incoming traffic. This leads to a kernel 'oops' or crash, resulting in a denial-of-service condition for the affected server.
Technical details
A NULL pointer dereference vulnerability exists in the AF_RXRPC implementation within the Linux kernel. The flaw is located in the rxrpc_alloc_incoming_call() function in net/rxrpc/call_accept.c, where the code fails to verify the existence of the rxrpc_backlog structure. If a service socket is bound but no calls are preallocated, an incoming call triggers a dereference of the unallocated backlog struct, causing a kernel oops. This can be exploited remotely without authentication to cause a Denial of Service (DoS). Patches have been released across multiple stable kernel branches to return NULL and abort the call if the backlog struct is missing.
Affected products
- Linux Linux Kernel 4.9 to 6.1.146
Timeline
- 2025-07-08: disclosed: Vulnerability reported by Tencent Zhuque Lab
- 2025-07-17: patched: Fixes committed to Linux stable trees
- 2025-08-16: advisory: CVE published
References
- https://git.kernel.org/stable/c/0eef29385d715d4c7fd707b18d4a9b76c76dd5e6
- https://git.kernel.org/stable/c/2c2e9ebeb036f9b1b09325ec5cfdfe0e78f357c3
- https://git.kernel.org/stable/c/880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4
- https://git.kernel.org/stable/c/bf0ca6a1bc4fb904b598137c6718785a107e3adf
- https://git.kernel.org/stable/c/d1ff5f9d2c5405681457262e23c720b08977c11f
- https://git.kernel.org/stable/c/efc1b2b7c1a308b60df8f36bc2d7ce16d3999364
- https://git.kernel.org/stable/c/f5e72b7824d08c206ce106d30cb37c4642900ccc