6.6-stable review patch. If anyone has any objections, please let me know.
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From: Paolo Abeni pabeni@redhat.com
commit 7679d34f97b7a09fd565f5729f79fd61b7c55329 upstream.
The MPTCP implementation of the IP_TOS socket option uses the lockless variant of the TOS manipulation helper and does not hold such lock at the helper invocation time.
Add the required locking.
Fixes: ffcacff87cd6 ("mptcp: Support for IP_TOS for MPTCP setsockopt()") Cc: stable@vger.kernel.org Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/457 Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts matttbe@kernel.org Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/mptcp/sockopt.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -737,8 +737,11 @@ static int mptcp_setsockopt_v4_set_tos(s val = inet_sk(sk)->tos; mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + bool slow;
+ slow = lock_sock_fast(ssk); __ip_sock_set_tos(ssk, val); + unlock_sock_fast(ssk, slow); } release_sock(sk);