CVE-2026-68289In 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.