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author | Alexey Kodanev <alexey.kodanev@oracle.com> | 2018-03-06 22:57:01 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-08 12:49:42 +0300 |
commit | e717aef0e7ed299b43812cd1a2bcf5888eafad9b (patch) | |
tree | f12834256496fb418e3f570be2b9e399cf9ecb19 /net/dccp | |
parent | 6ab380698a5301fa8ccf995d946351cf4047ee52 (diff) | |
download | linux-e717aef0e7ed299b43812cd1a2bcf5888eafad9b.tar.xz |
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>
Diffstat (limited to 'net/dccp')
-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 dad5493c7c5a..2b8fd8cd709d 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -792,6 +792,11 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 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_fromiovec(skb_put(skb, len), msg->msg_iov, len); if (rc != 0) |