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authorJon Paul Maloy <jon.maloy@ericsson.com>2017-02-23 11:10:31 -0500
committerDavid S. Miller <davem@davemloft.net>2017-02-24 11:42:54 -0500
commit681a55d71799b575f46fe94121728cf67460d1c3 (patch)
tree571316773e7f47c7bdb2d86fa599c93de0d76eaa /net/tipc
parentfbf68229ffe7e12c78b55714de08c1c34a2e2047 (diff)
downloadlinux-681a55d71799b575f46fe94121728cf67460d1c3.tar.bz2
tipc: move premature initilalization of stack variables
In the function tipc_rcv() we initialize a couple of stack variables from the message header before that same header has been validated. In rare cases when the arriving header is non-linar, the validation function itself may linearize the buffer by calling skb_may_pull(), while the wrongly initialized stack fields are not updated accordingly. We fix this in this commit. Reported-by: Matthew Wong <mwong@sonusnet.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc')
-rw-r--r--net/tipc/node.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/net/tipc/node.c b/net/tipc/node.c
index e9295fa3a554..4512e83652b1 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1505,19 +1505,21 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
{
struct sk_buff_head xmitq;
struct tipc_node *n;
- struct tipc_msg *hdr = buf_msg(skb);
- int usr = msg_user(hdr);
+ struct tipc_msg *hdr;
int bearer_id = b->identity;
struct tipc_link_entry *le;
- u16 bc_ack = msg_bcast_ack(hdr);
u32 self = tipc_own_addr(net);
- int rc = 0;
+ int usr, rc = 0;
+ u16 bc_ack;
__skb_queue_head_init(&xmitq);
- /* Ensure message is well-formed */
+ /* Ensure message is well-formed before touching the header */
if (unlikely(!tipc_msg_validate(skb)))
goto discard;
+ hdr = buf_msg(skb);
+ usr = msg_user(hdr);
+ bc_ack = msg_bcast_ack(hdr);
/* Handle arrival of discovery or broadcast packet */
if (unlikely(msg_non_seq(hdr))) {