Subject: [PATCH net-next 1/2] tls: rx: release the sock lock on locking timeout

From: Jakub Kicinski <[email-masked]>
Date: Wed, 20 Jul 2022 13:37:00 -0700

Eric reports we should release the socket lock if the entire
"grab reader lock" operation has failed. The callers assume
they don't have to release it or otherwise unwind.

Reported-by: Eric Dumazet <[email-masked]>
Reported-by: [email-masked]
Fixes: 4cbc325ed6b4 ("tls: rx: allow only one reader at a time")
Signed-off-by: Jakub Kicinski <[email-masked]>
---
 net/tls/tls_sw.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 518401997539..0fc24a5ce208 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1846,6 +1846,7 @@ static long tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
 			       bool nonblock)
 {
 	long timeo;
+	int err;
 
 	lock_sock(sk);
 
@@ -1861,15 +1862,23 @@ static long tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
 			      !READ_ONCE(ctx->reader_present), &wait);
 		remove_wait_queue(&ctx->wq, &wait);
 
-		if (!timeo)
-			return -EAGAIN;
-		if (signal_pending(current))
-			return sock_intr_errno(timeo);
+		if (timeo <= 0) {
+			err = -EAGAIN;
+			goto err_unlock;
+		}
+		if (signal_pending(current)) {
+			err = sock_intr_errno(timeo);
+			goto err_unlock;
+		}
 	}
 
 	WRITE_ONCE(ctx->reader_present, 1);
 
 	return timeo;
+
+err_unlock:
+	release_sock(sk);
+	return err;
 }
 
 static void tls_rx_reader_unlock(struct sock *sk, struct tls_sw_context_rx *ctx)
-- 
2.36.1