CVE-2026-53292 net: phonet: do not BUG_ON() in pn_socket_autobind() on failed bind
A local attacker can trigger a kernel panic in the Phonet socket implementation by sending a specific message, causing a denial of service.
- 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-2026-53292?
CVE-2026-53292 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Jun 2026. 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:
net: phonet: do not BUG_ON() in pn_socket_autobind() on failed bind
syzbot reported a kernel BUG triggered from pn_socket_sendmsg() via pn_socket_autobind():
kernel BUG at net/phonet/socket.c:213! RIP: 0010:pn_socket_autobind net/phonet/socket.c:213 [inline] RIP: 0010:pn_socket_sendmsg+0x240/0x250 net/phonet/socket.c:421 Call Trace: sock_sendmsg_nosec+0x112/0x150 net/socket.c:797 __sock_sendmsg net/socket.c:812 [inline] __sys_sendto+0x402/0x590 net/socket.c:2280 ...
pn_socket_autobind() calls pn_socket_bind() with port 0 and, on -EINVAL, assumes the socket was already bound and asserts that the port is non-zero:
err = pn_socket_bind(sock, ..., sizeof(struct sockaddr_pn)); if (err != -EINVAL) return err; BUG_ON(!pn_port(pn_sk(sock->sk)->sobject)); return 0; /* socket was already bound */
However pn_socket_bind() also returns -EINVAL when sk->sk_state is not TCP_CLOSE, even when the socket has never been bound and pn_port() is still 0. In that case the BUG_ON() fires and panics the kernel from a user-triggerable path.
Treat the "bind returned -EINVAL but pn_port() is still 0" case as a regular error and propagate -EINVAL to the caller instead of crashing. Existing callers already translate a non-zero return from pn_socket_autobind() into -ENOBUFS/-EAGAIN, so returning -EINVAL here only changes behaviour from panic to a normal errno.
Weakness: CWE-617
Which versions are affected by CVE-2026-53292?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53292?
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-2026-53292 being exploited?
There is no known exploitation of CVE-2026-53292 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-91317, BELL-CVE-2026-53292, DEBIAN-CVE-2026-53292, GHSA-mfj5-8wwq-98rr, ROOT-OS-DEBIAN-11-CVE-2026-53292, ROOT-OS-DEBIAN-12-CVE-2026-53292 and 4 more.