CVE-2026-43198
Description
AI Translation Available
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix potential race in tcp_v6_syn_recv_sock()
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.
After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.
Since newinet->pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.
Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.
This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context.
https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b
https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae
https://git.kernel.org/stable/c/fe89b2f05b854847784f91127319172945c1fadd