CVE-2026-68289: tipc: fix integer overflow in tipc_recvmsg() and tipc_recvstream()
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix integer overflow in tipcrecvmsg() and tipcrecvstream()
In tipcrecvmsg(), the copy length is computed as:
copy = mint(int, dlen - offset, buflen);
buflen is sizet but mint(int, ...) casts it to int. When buflen exceeds INTMAX (e.g. 0xFFFFFFFF via iouring provided buffers), it wraps negative, wins the comparison, and the negative copy length propagates to simplecopytoiter() where int-to-sizet promotion makes it SIZEMAX, triggering a WARNON. tipcrecvstream() has the same pattern.
Kernel panic - not syncing: kernel: paniconwarn set ... RIP: 0010:simplecopytoiter+0x9e/0xd0 (net/core/datagram.c:521) Call Trace: skbdatagramiter+0x123/0x8b0 (net/core/datagram.c:402) skbcopydatagramiter+0x77/0x1a0 (net/core/datagram.c:534) tipcrecvmsg+0x3d7/0xe80 (net/tipc/socket.c:1934) iorecvmsg+0x47e/0xda0
Fix by changing mint(int, ...) to mint(sizet, ...) 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Apply the kernel fix for TIPC: in tipc_recvmsg() (and tipc_recvstream() per the report), change the calculation/call from min_t(int, ...) to min_t(size_t, ...) so that buflen is not cast to int and the copy length computation is done with size_t.
Linux kernel (tipc) min_t(int, ...) parameter type = min_t(size_t, ...)
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68289?
CVE-2026-68289 has a risk score of 33, indicating a moderate level of vulnerability.
How does CVE-2026-68289 affect the Linux kernel?
CVE-2026-68289 affects the Linux kernel by introducing an integer overflow in the tipc_recvmsg() and tipc_recvstream() functions.
What causes the integer overflow in CVE-2026-68289?
The integer overflow is caused by the cast of size_t 'buflen' to int in the min_t() function during length computation.
How can I mitigate CVE-2026-68289?
Mitigation for CVE-2026-68289 involves updating to the patched version of the Linux kernel that resolves this vulnerability.
When was CVE-2026-68289 published?
CVE-2026-68289 was published on August 10, 2026.