CVE-2024-26752

In the Linux kernel, the following vulnerability has been resolved: l2tp: pass correct message length to ip6_append_data l2tp_ip6_sendmsg needs to avoid accounting for the transport header twice when splicing more data into an already partially-occupied skbuff. To manage this, we check whether the skbuff contains data using skb_queue_empty when deciding how much data to append using ip6_append_data. However, the code which performed the calculation was incorrect: ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0; ...due to C operator precedence, this ends up setting ulen to transhdrlen for messages with a non-zero length, which results in corrupted packets on the wire. Add parentheses to correct the calculation in line with the original intent.

• linux linux kernel (>= 4.19.296 < 4.19.308) • linux linux kernel (>= 5.4.258 < 5.4.270) • linux linux kernel (>= 5.10.198 < 5.10.211) • linux linux kernel (>= 5.15.135 < 5.15.150) • linux linux kernel (>= 6.1.57 < 6.1.80) • linux linux kernel (>= 6.6 < 6.6.19) • linux linux kernel (>= 6.7 < 6.7.7) • linux linux kernel 4.14.327 • linux linux kernel 6.5.7 • linux linux kernel 6.8 • debian debian linux 10.0