[PATCH 4.20 25/80] net: tls: Fix deadlock in free_resources tx

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dave Watson <davejwatson@xxxxxx>

[ 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 <davejwatson@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/tls/tls_sw.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1768,7 +1768,9 @@ void tls_sw_free_resources_tx(struct soc
 	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);