diff options
| author | subashab@codeaurora.org <subashab@codeaurora.org> | 2015-01-23 22:26:02 +0000 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-02-10 11:16:50 +0100 |
| commit | 757651a70148d9e1695daa6709988e09fd940cec (patch) | |
| tree | ff1db09e58ae4eb9da0753cb9888d4d9bc9bccde | |
| parent | fd09a4de42024767c0fb9ea797e96454b0054130 (diff) | |
ping: Fix race in free in receive path
[ Upstream commit fc752f1f43c1c038a2c6ae58cc739ebb5953ccb0 ]
An exception is seen in ICMP ping receive path where the skb
destructor sock_rfree() tries to access a freed socket. This happens
because ping_rcv() releases socket reference with sock_put() and this
internally frees up the socket. Later icmp_rcv() will try to free the
skb and as part of this, skb destructor is called and which leads
to a kernel panic as the socket is freed already in ping_rcv().
-->|exception
-007|sk_mem_uncharge
-007|sock_rfree
-008|skb_release_head_state
-009|skb_release_all
-009|__kfree_skb
-010|kfree_skb
-011|icmp_rcv
-012|ip_local_deliver_finish
Fix this incorrect free by cloning this skb and processing this cloned
skb instead.
This patch was suggested by Eric Dumazet
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | net/ipv4/ping.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 8bd51f49aa96..81c92f61d77c 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -959,8 +959,11 @@ void ping_rcv(struct sk_buff *skb) sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); if (sk != NULL) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + pr_debug("rcv on socket %p\n", sk); - ping_queue_rcv_skb(sk, skb_get(skb)); + if (skb2) + ping_queue_rcv_skb(sk, skb2); sock_put(sk); return; } |