From b5c52908d52c6c8eb8933264aa6087a0600fd892 Mon Sep 17 00:00:00 2001 From: Gang Yan Date: Mon, 27 Apr 2026 21:54:34 +0200 Subject: mptcp: fix scheduling with atomic in timestamp sockopt Using lock_sock_fast() (atomic context) around sock_set_timestamp() and sock_set_timestamping() is unsafe, as both helpers can sleep. Replace lock_sock_fast() with sleepable lock_sock()/release_sock() to avoid scheduling while atomic panic. Fixes: 9061f24bf82e ("mptcp: sockopt: propagate timestamp request to subflows") Cc: stable@vger.kernel.org Reported-by: Sashiko Closes: https://sashiko.dev/#/patchset/20260420093343.16443-1-gang.yan@linux.dev Signed-off-by: Gang Yan Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260427-net-mptcp-misc-fixes-7-1-rc2-v1-2-7432b7f279fa@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/sockopt.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 79db15903e7a..0efe40be2fde 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -159,10 +159,10 @@ static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optnam lock_sock(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); - bool slow = lock_sock_fast(ssk); + lock_sock(ssk); sock_set_timestamp(ssk, optname, !!val); - unlock_sock_fast(ssk, slow); + release_sock(ssk); } release_sock(sk); @@ -235,10 +235,10 @@ static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk, mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); - bool slow = lock_sock_fast(ssk); + lock_sock(ssk); sock_set_timestamping(ssk, optname, timestamping); - unlock_sock_fast(ssk, slow); + release_sock(ssk); } release_sock(sk); -- cgit v1.2.3