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| author | Jon Paul Maloy <jon.maloy@ericsson.com> | 2017-02-23 19:10:31 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-24 19:42:54 +0300 |
| commit | 681a55d71799b575f46fe94121728cf67460d1c3 (patch) | |
| tree | 571316773e7f47c7bdb2d86fa599c93de0d76eaa /net | |
| parent | fbf68229ffe7e12c78b55714de08c1c34a2e2047 (diff) | |
| download | linux-681a55d71799b575f46fe94121728cf67460d1c3.tar.xz | |
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')
| -rw-r--r-- | net/tipc/node.c | 12 |
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))) { |