From: Hangyu Hua <hbh25y@gmail.com>
To: jreuter@yaina.de, ralf@linux-mips.org, davem@davemloft.net,
kuba@kernel.org
Cc: linux-hams@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Hangyu Hua <hbh25y@gmail.com>
Subject: [PATCH net] ax25: use after free in ax25_connect
Date: Tue, 11 Jan 2022 12:20:48 +0800 [thread overview]
Message-ID: <20220111042048.43532-1-hbh25y@gmail.com> (raw)
sk_to_ax25(sk) needs to be called after lock_sock(sk) to avoid UAF
caused by a race condition.
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
---
net/ax25/af_ax25.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index cfca99e295b8..c5d62420a2a8 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1127,7 +1127,7 @@ static int __must_check ax25_connect(struct socket *sock,
struct sockaddr *uaddr, int addr_len, int flags)
{
struct sock *sk = sock->sk;
- ax25_cb *ax25 = sk_to_ax25(sk), *ax25t;
+ ax25_cb *ax25, *ax25t;
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr;
ax25_digi *digi = NULL;
int ct = 0, err = 0;
@@ -1155,6 +1155,8 @@ static int __must_check ax25_connect(struct socket *sock,
lock_sock(sk);
+ ax25 = sk_to_ax25(sk);
+
/* deal with restarts */
if (sock->state == SS_CONNECTING) {
switch (sk->sk_state) {
--
2.25.1
next reply other threads:[~2022-01-11 4:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-11 4:20 Hangyu Hua [this message]
2022-01-11 20:56 ` [PATCH net] ax25: use after free in ax25_connect Eric Dumazet
2022-01-12 2:13 ` Hangyu Hua
2022-01-12 9:59 ` Eric Dumazet
2022-01-12 11:11 ` Hangyu Hua
2022-01-14 6:54 ` Hangyu Hua
2022-01-14 15:19 ` Eric Dumazet
2022-01-17 1:35 ` Hangyu Hua
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