[PATCH 5.4 25/62] chtls: Added a check to avoid NULL pointer dereference

From: Ayush Sawal <ayush.sawal@chelsio.com>

[ Upstream commit eade1e0a4fb31d48eeb1589d9bb859ae4dd6181d ]

In case of server removal lookup_stid() may return NULL pointer, which
is used as listen_ctx. So added a check before accessing this pointer.

Fixes: cc35c88ae4db ("crypto : chtls - CPL handler definition")
Signed-off-by: Vinay Kumar Yadav <redacted>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/crypto/chelsio/chtls/chtls_cm.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/crypto/chelsio/chtls/chtls_cm.c
+++ b/drivers/crypto/chelsio/chtls/chtls_cm.c

@@ -1453,6 +1453,11 @@ static int chtls_pass_establish(struct c
 			sk_wake_async(sk, 0, POLL_OUT);
 
 		data = lookup_stid(cdev->tids, stid);
+		if (!data) {
+			/* listening server close */
+			kfree_skb(skb);
+			goto unlock;
+		}
 		lsk = ((struct listen_ctx *)data)->lsk;
 
 		bh_lock_sock(lsk);