diff mbox series

[net,4/6] mptcp: fix data race around msk->first access

Message ID 20230531-send-net-20230531-v1-4-47750c420571@kernel.org (mailing list archive)
State Accepted
Commit 1b1b43ee7a208096ecd79e626f2fc90d4a321111
Delegated to: Netdev Maintainers
Headers show
Series mptcp: Fixes for connect timeout, access annotations, and subflow init | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 11 this patch: 11
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 11 this patch: 11
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 24 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Mat Martineau May 31, 2023, 7:37 p.m. UTC 
From: Paolo Abeni <pabeni@redhat.com>

The first subflow socket is accessed outside the msk socket lock
by mptcp_subflow_fail(), we need to annotate each write access
with WRITE_ONCE, but a few spots still lacks it.

Fixes: 76a13b315709 ("mptcp: invoke MP_FAIL response when needed")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
---
 net/mptcp/protocol.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 2ecd0117ab1b..a7dd7d8c9af2 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -90,7 +90,7 @@  static int __mptcp_socket_create(struct mptcp_sock *msk)
 	if (err)
 		return err;
 
-	msk->first = ssock->sk;
+	WRITE_ONCE(msk->first, ssock->sk);
 	WRITE_ONCE(msk->subflow, ssock);
 	subflow = mptcp_subflow_ctx(ssock->sk);
 	list_add(&subflow->node, &msk->conn_list);
@@ -2419,7 +2419,7 @@  static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 	sock_put(ssk);
 
 	if (ssk == msk->first)
-		msk->first = NULL;
+		WRITE_ONCE(msk->first, NULL);
 
 out:
 	if (ssk == msk->last_snd)
@@ -2720,7 +2720,7 @@  static int __mptcp_init_sock(struct sock *sk)
 	WRITE_ONCE(msk->rmem_released, 0);
 	msk->timer_ival = TCP_RTO_MIN;
 
-	msk->first = NULL;
+	WRITE_ONCE(msk->first, NULL);
 	inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
 	WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
 	WRITE_ONCE(msk->allow_infinite_fallback, true);