[34-longterm 195/260] Phonet: Correct header retrieval after pskb_may_pull

From: Paul Gortmaker
Date: Sun Jan 02 2011 - 02:38:47 EST

From: Kumar Sanghvi <kumar.sanghvi@xxxxxxxxxxxxxx>

commit a91e7d471e2e384035b9746ea707ccdcd353f5dd upstream.

Retrieve the header after doing pskb_may_pull since, pskb_may_pull
could change the buffer structure.

This is based on the comment given by Eric Dumazet on Phonet
Pipe controller patch for a similar problem.

Signed-off-by: Kumar Sanghvi <kumar.sanghvi@xxxxxxxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
Acked-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Acked-by: RÃmi Denis-Courmont <remi.denis-courmont@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
net/phonet/pep.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index e2a9576..dc1e8ae 100644
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -225,12 +225,13 @@ static void pipe_grant_credits(struct sock *sk)
static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
struct pep_sock *pn = pep_sk(sk);
- struct pnpipehdr *hdr = pnp_hdr(skb);
+ struct pnpipehdr *hdr;
int wake = 0;

if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
return -EINVAL;

+ hdr = pnp_hdr(skb);
if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/