[PATCH 6.1 1/1] tls: fix race between tx work scheduling and socket close

[Lee Jones <lee@kernel.org>]

From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit e01e3934a1b2d122919f73bc6ddbe1cdafc4bbdb ]

Similarly to previous commit, the submitting thread (recvmsg/sendmsg)
may exit as soon as the async crypto handler calls complete().
Reorder scheduling the work before calling complete().
This seems more logical in the first place, as it's
the inverse order of what the submitting thread will do.

Reported-by: valis <sec@valis.email>
Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 6db22d6c7a6dc914b12c0469b94eb639b6a8a146)
[Lee: Fixed merge-conflict in Stable branches linux-6.1.y and older]
Signed-off-by: Lee Jones <lee@kernel.org>
---
 net/tls/tls_sw.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 2bd27b77769cb..d53587ff9ddea 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -449,7 +449,6 @@ static void tls_encrypt_done(crypto_completion_data_t *data, int err)
 	struct scatterlist *sge;
 	struct sk_msg *msg_en;
 	struct tls_rec *rec;
-	bool ready = false;
 	struct sock *sk;
 
 	rec = container_of(aead_req, struct tls_rec, aead_req);
@@ -486,19 +485,16 @@ static void tls_encrypt_done(crypto_completion_data_t *data, int err)
 		/* If received record is at head of tx_list, schedule tx */
 		first_rec = list_first_entry(&ctx->tx_list,
 					     struct tls_rec, list);
-		if (rec == first_rec)
-			ready = true;
+		if (rec == first_rec) {
+			/* Schedule the transmission */
+			if (!test_and_set_bit(BIT_TX_SCHEDULED,
+					      &ctx->tx_bitmask))
+				schedule_delayed_work(&ctx->tx_work.work, 1);
+		}
 	}
 
 	if (atomic_dec_and_test(&ctx->encrypt_pending))
 		complete(&ctx->async_wait.completion);
-
-	if (!ready)
-		return;
-
-	/* Schedule the transmission */
-	if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
-		schedule_delayed_work(&ctx->tx_work.work, 1);
 }
 
 static int tls_encrypt_async_wait(struct tls_sw_context_tx *ctx)
-- 
2.44.0.278.ge034bb2e1d-goog