[PATCH 4.19 17/96] net/tls: prevent bad memory access in tls_is_sk_tx_device_offloaded()

From: Greg Kroah-Hartman
Date: Wed Apr 24 2019 - 13:50:30 EST


From: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>

[ Upstream commit b4f47f3848eb70986f75d06112af7b48b7f5f462 ]

Unlike '&&' operator, the '&' does not have short-circuit
evaluation semantics. IOW both sides of the operator always
get evaluated. Fix the wrong operator in
tls_is_sk_tx_device_offloaded(), which would lead to
out-of-bounds access for for non-full sockets.

Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@xxxxxxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/tls.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -317,7 +317,7 @@ tls_validate_xmit_skb(struct sock *sk, s
static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
{
#ifdef CONFIG_SOCK_VALIDATE_XMIT
- return sk_fullsock(sk) &
+ return sk_fullsock(sk) &&
(smp_load_acquire(&sk->sk_validate_xmit_skb) ==
&tls_validate_xmit_skb);
#else