Re: [PATCH] can: check for null sk before deferencing it via the call to sock_net

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 09/08/2017 05:02 PM, Colin King wrote:
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The assignment of net via call sock_net will dereference sk. This
is performed before a sanity null check on sk, so there could be
a potential null dereference on the sock_net call if sk is null.
Fix this by assigning net after the sk null check. Also replace
the sk == NULL with the more usual !sk idiom.

Detected by CoverityScan CID#1431862 ("Dereference before null check")

Fixes: 384317ef4187 ("can: network namespace support for CAN_BCM protocol")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>


Thanks Collin!

---
  net/can/bcm.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 47a8748d953a..a3791674b8ce 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -1493,13 +1493,14 @@ static int bcm_init(struct sock *sk)
  static int bcm_release(struct socket *sock)
  {
  	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
+	struct net *net;
  	struct bcm_sock *bo;
  	struct bcm_op *op, *next;
- if (sk == NULL)
+	if (!sk)
  		return 0;
+ net = sock_net(sk);
  	bo = bcm_sk(sk);
/* remove bcm_ops, timer, rx_unregister(), etc. */

--
To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Development]     [Kernel Announce]     [Kernel Newbies]     [Linux Networking Development]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Device Mapper]

  Powered by Linux