This is a note to let you know that I've just added the patch titled
net: sock: validate data_len before allocating skb in sock_alloc_send_pskb()
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-sock-validate-data_len-before-allocating-skb-in-sock_alloc_send_pskb.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From fd2a6fa5a30dc467188e6a847fc1abf820f06e80 Mon Sep 17 00:00:00 2001
From: Jason Wang <[email protected]>
Date: Wed, 30 May 2012 21:18:10 +0000
Subject: net: sock: validate data_len before allocating skb in
sock_alloc_send_pskb()
From: Jason Wang <[email protected]>
[ Upstream commit cc9b17ad29ecaa20bfe426a8d4dbfb94b13ff1cc ]
We need to validate the number of pages consumed by data_len, otherwise frags
array could be overflowed by userspace. So this patch validate data_len and
return -EMSGSIZE when data_len may occupies more frags than MAX_SKB_FRAGS.
Signed-off-by: Jason Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/core/sock.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1501,6 +1501,11 @@ struct sk_buff *sock_alloc_send_pskb(str
gfp_t gfp_mask;
long timeo;
int err;
+ int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+
+ err = -EMSGSIZE;
+ if (npages > MAX_SKB_FRAGS)
+ goto failure;
gfp_mask = sk->sk_allocation;
if (gfp_mask & __GFP_WAIT)
@@ -1519,14 +1524,12 @@ struct sk_buff *sock_alloc_send_pskb(str
if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
skb = alloc_skb(header_len, gfp_mask);
if (skb) {
- int npages;
int i;
/* No pages, we're done... */
if (!data_len)
break;
- npages = (data_len + (PAGE_SIZE - 1)) >>
PAGE_SHIFT;
skb->truesize += data_len;
skb_shinfo(skb)->nr_frags = npages;
for (i = 0; i < npages; i++) {
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/net-sock-validate-data_len-before-allocating-skb-in-sock_alloc_send_pskb.patch
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