diff options
| author | Alexey Kodanev <alexey.kodanev@oracle.com> | 2018-03-06 22:57:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-31 18:12:33 +0200 |
| commit | de31c391673aeb2c1d09552ac75a6b7ee96d65ac (patch) | |
| tree | 2c7cb41b6751ea51d539fb13a992bc7c88374c61 | |
| parent | 51b4111f7212d488cb081e287396c369dd20cb9c (diff) | |
dccp: check sk for closed state in dccp_sendmsg()
[ Upstream commit 67f93df79aeefc3add4e4b31a752600f834236e2 ]
dccp_disconnect() sets 'dp->dccps_hc_tx_ccid' tx handler to NULL,
therefore if DCCP socket is disconnected and dccp_sendmsg() is
called after it, it will cause a NULL pointer dereference in
dccp_write_xmit().
This crash and the reproducer was reported by syzbot. Looks like
it is reproduced if commit 69c64866ce07 ("dccp: CVE-2017-8824:
use-after-free in DCCP code") is applied.
Reported-by: syzbot+f99ab3887ab65d70f816@syzkaller.appspotmail.com
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/dccp/proto.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 9d43c1f40274..ff3b058cf58c 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -789,6 +789,11 @@ int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (skb == NULL) goto out_release; + if (sk->sk_state == DCCP_CLOSED) { + rc = -ENOTCONN; + goto out_discard; + } + skb_reserve(skb, sk->sk_prot->max_header); rc = memcpy_from_msg(skb_put(skb, len), msg, len); if (rc != 0) |