Subject: [PATCH 24/33] net: tls: Fix deadlock in free_resources tx

From: Dave Watson <[email-masked]>
Date: Sun, 27 Jan 2019 00:59:03 +0000

[ Upstream commit 1023121375c6b0b3dc00334983c762ba2b76cb19 ]

If there are outstanding async tx requests (when crypto returns EINPROGRESS),
there is a potential deadlock: the tx work acquires the lock, while we
cancel_delayed_work_sync() while holding the lock.  Drop the lock while waiting
for the work to complete.

Fixes: a42055e8d2c30 ("Add support for async encryption of records...")
Signed-off-by: Dave Watson <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/tls/tls_sw.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 29b27858fff1..4be2320ec7ce 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1768,7 +1768,9 @@ void tls_sw_free_resources_tx(struct sock *sk)
 	if (atomic_read(&ctx->encrypt_pending))
 		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
 
+	release_sock(sk);
 	cancel_delayed_work_sync(&ctx->tx_work.work);
+	lock_sock(sk);
 
 	/* Tx whatever records we can transmit and abandon the rest */
 	tls_tx_records(sk, -1);
-- 
2.20.1