diff options
| author | Jiayuan Chen <jiayuan.chen@shopee.com> | 2026-03-11 15:06:02 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-25 11:13:25 +0100 |
| commit | a12254050e3050f1011cd24f3b880a6882d0139d (patch) | |
| tree | 8913cf57d083bd48ba9891dd33baa442d442c351 /net/rose | |
| parent | 1fd81151f65927fd9edb8ecd12ad45527dbbe5ab (diff) | |
net/rose: fix NULL pointer dereference in rose_transmit_link on reconnect
[ Upstream commit e1f0a18c9564cdb16523c802e2c6fe5874e3d944 ]
syzkaller reported a bug [1], and the reproducer is available at [2].
ROSE sockets use four sk->sk_state values: TCP_CLOSE, TCP_LISTEN,
TCP_SYN_SENT, and TCP_ESTABLISHED. rose_connect() already rejects
calls for TCP_ESTABLISHED (-EISCONN) and TCP_CLOSE with SS_CONNECTING
(-ECONNREFUSED), but lacks a check for TCP_SYN_SENT.
When rose_connect() is called a second time while the first connection
attempt is still in progress (TCP_SYN_SENT), it overwrites
rose->neighbour via rose_get_neigh(). If that returns NULL, the socket
is left with rose->state == ROSE_STATE_1 but rose->neighbour == NULL.
When the socket is subsequently closed, rose_release() sees
ROSE_STATE_1 and calls rose_write_internal() ->
rose_transmit_link(skb, NULL), causing a NULL pointer dereference.
Per connect(2), a second connect() while a connection is already in
progress should return -EALREADY. Add this missing check for
TCP_SYN_SENT to complete the state validation in rose_connect().
[1] https://syzkaller.appspot.com/bug?extid=d00f90e0af54102fb271
[2] https://gist.github.com/mrpre/9e6779e0d13e2c66779b1653fef80516
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+d00f90e0af54102fb271@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69694d6f.050a0220.58bed.0027.GAE@google.com/T/
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260311070611.76913-1-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/rose')
| -rw-r--r-- | net/rose/af_rose.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c index c0f5a515a8ce..de18af4e4066 100644 --- a/net/rose/af_rose.c +++ b/net/rose/af_rose.c @@ -811,6 +811,11 @@ static int rose_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int goto out_release; } + if (sk->sk_state == TCP_SYN_SENT) { + err = -EALREADY; + goto out_release; + } + sk->sk_state = TCP_CLOSE; sock->state = SS_UNCONNECTED; |