[PATCH 5.15 193/279] tipc: check for null after calling kmemdup

Greg Kroah-Hartman
2021-11-24T14:02:59Z

From: Tadeusz Struk <tadeusz.struk@linaro.org>

commit 3e6db079751afd527bf3db32314ae938dc571916 upstream.

kmemdup can return a null pointer so need to check for it, otherwise
the null key will be dereferenced later in tipc_crypto_key_xmit as
can be seen in the trace [1].

Cc: tipc-discussion@lists.sourceforge.net
Cc: stable@vger.kernel.org # 5.15, 5.14, 5.10

[1] https://syzkaller.appspot.com/bug?id=bca180abb29567b189efdbdb34cbf7ba851c2a58

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Link: https://lore.kernel.org/r/20211115160143.5099-1-tadeusz.struk@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tipc/crypto.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/net/tipc/crypto.c
+++ b/net/tipc/crypto.c
@@ -597,6 +597,10 @@ static int tipc_aead_init(struct tipc_ae
tmp->cloned = NULL;
tmp->authsize = TIPC_AES_GCM_TAG_SIZE;
tmp->key = kmemdup(ukey, tipc_aead_key_size(ukey), GFP_KERNEL);
+ if (!tmp->key) {
+ tipc_aead_free(&tmp->rcu);
+ return -ENOMEM;
+ }
memcpy(&tmp->salt, ukey->key + keylen, TIPC_AES_GCM_SALT_SIZE);
atomic_set(&tmp->users, 0);
atomic64_set(&tmp->seqno, 0);