CVE-2026-68289 tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()

Q: Is CVE-2026-68289 being exploited?

There is no known exploitation of CVE-2026-68289 in the wild and no public exploit code.

Not scored Published 10 Aug 2026 Updated 3 Oct 2026

An integer overflow in the Linux kernel TIPC module allows local attackers to trigger a kernel panic via crafted io_uring operations.

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-2026-68289?

CVE-2026-68289 is a vulnerability in Linux, published on 10 Aug 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:

tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()

In tipc_recvmsg(), the copy length is computed as:

copy = min_t(int, dlen - offset, buflen);

buflen is size_t but min_t(int, ...) casts it to int. When buflen exceeds INT_MAX (e.g. 0xFFFFFFFF via io_uring provided buffers), it wraps negative, wins the comparison, and the negative copy length propagates to simple_copy_to_iter() where int-to-size_t promotion makes it SIZE_MAX, triggering a WARN_ON. tipc_recvstream() has the same pattern.

Kernel panic - not syncing: kernel: panic_on_warn set ... RIP: 0010:simple_copy_to_iter+0x9e/0xd0 (net/core/datagram.c:521) Call Trace: __skb_datagram_iter+0x123/0x8b0 (net/core/datagram.c:402) skb_copy_datagram_iter+0x77/0x1a0 (net/core/datagram.c:534) tipc_recvmsg+0x3d7/0xe80 (net/tipc/socket.c:1934) io_recvmsg+0x47e/0xda0

Fix by changing min_t(int, ...) to min_t(size_t, ...) in both functions. The result is always <= (dlen - offset), which is bounded by TIPC maximum message size (0x1ffff bytes), so the implicit narrowing on assignment to int copy is always safe.

Which versions are affected by CVE-2026-68289?

How do I fix CVE-2026-68289?

Apply the vendor's patch.

Is CVE-2026-68289 being exploited?