6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paolo Abeni <pabeni@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/457
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matttbe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231114-upstream-net-20231113-mptcp-misc-fixes-6-7-rc2-v1-4-7b9cd6a7b7f4@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
