diff options
| author | Daniel Borkmann | 2013-09-07 20:51:21 +0200 |
|---|---|---|
| committer | David S. Miller | 2013-09-11 16:10:00 -0400 |
| commit | 88362ad8f9a6cea787420b57cc27ccacef000dbe (patch) | |
| tree | 0222ec4934353c9f700517162f3d978fa21b174b /net | |
| parent | a0fb05d1aef0f5df936f80b726d1b3bfd4275f95 (diff) | |
net: sctp: fix smatch warning in sctp_send_asconf_del_ip
This was originally reported in [1] and posted by Neil Horman [2], he said:
Fix up a missed null pointer check in the asconf code. If we don't find
a local address, but we pass in an address length of more than 1, we may
dereference a NULL laddr pointer. Currently this can't happen, as the only
users of the function pass in the value 1 as the addrcnt parameter, but
its not hot path, and it doesn't hurt to check for NULL should that ever
be the case.
The callpath from sctp_asconf_mgmt() looks okay. But this could be triggered
from sctp_setsockopt_bindx() call with SCTP_BINDX_REM_ADDR and addrcnt > 1
while passing all possible addresses from the bind list to SCTP_BINDX_REM_ADDR
so that we do *not* find a single address in the association's bind address
list that is not in the packed array of addresses. If this happens when we
have an established association with ASCONF-capable peers, then we could get
a NULL pointer dereference as we only check for laddr == NULL && addrcnt == 1
and call later sctp_make_asconf_update_ip() with NULL laddr.
BUT: this actually won't happen as sctp_bindx_rem() will catch such a case
and return with an error earlier. As this is incredably unintuitive and error
prone, add a check to catch at least future bugs here. As Neil says, its not
hot path. Introduced by 8a07eb0a5 ("sctp: Add ASCONF operation on the
single-homed host").
[1] http://www.spinics.net/lists/linux-sctp/msg02132.html
[2] http://www.spinics.net/lists/linux-sctp/msg02133.html
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Michio Honda <micchie@sfc.wide.ad.jp>
Acked-By: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/socket.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 5462bbbb52ef..911b71b26b0e 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -806,6 +806,9 @@ static int sctp_send_asconf_del_ip(struct sock *sk, goto skip_mkasconf; } + if (laddr == NULL) + return -EINVAL; + /* We do not need RCU protection throughout this loop * because this is done under a socket lock from the * setsockopt call. |