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| author | Matthew Daley <mattjd@gmail.com> | 2011-10-14 18:45:04 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-17 19:31:39 -0400 |
| commit | cb101ed2c3c7c0224d16953fe77bfb9d6c2cb9df (patch) | |
| tree | 3d266ac18673ebc85a99e4d10d8d381ff1ebd782 /net/x25/x25_facilities.c | |
| parent | c7fd0d48bde943e228e9c28ce971a22d6a1744c4 (diff) | |
| download | linux-cb101ed2c3c7c0224d16953fe77bfb9d6c2cb9df.tar.gz linux-cb101ed2c3c7c0224d16953fe77bfb9d6c2cb9df.tar.bz2 linux-cb101ed2c3c7c0224d16953fe77bfb9d6c2cb9df.zip | |
x25: Handle undersized/fragmented skbs
There are multiple locations in the X.25 packet layer where a skb is
assumed to be of at least a certain size and that all its data is
currently available at skb->data. These assumptions are not checked,
hence buffer overreads may occur. Use pskb_may_pull to check these
minimal size assumptions and ensure that data is available at skb->data
when necessary, as well as use skb_copy_bits where needed.
Signed-off-by: Matthew Daley <mattjd@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: stable <stable@kernel.org>
Acked-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/x25/x25_facilities.c')
| -rw-r--r-- | net/x25/x25_facilities.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c index f77e4e75f914..36384a1fa9f2 100644 --- a/net/x25/x25_facilities.c +++ b/net/x25/x25_facilities.c @@ -44,7 +44,7 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities, struct x25_dte_facilities *dte_facs, unsigned long *vc_fac_mask) { - unsigned char *p = skb->data; + unsigned char *p; unsigned int len; *vc_fac_mask = 0; @@ -60,14 +60,16 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities, memset(dte_facs->called_ae, '\0', sizeof(dte_facs->called_ae)); memset(dte_facs->calling_ae, '\0', sizeof(dte_facs->calling_ae)); - if (skb->len < 1) + if (!pskb_may_pull(skb, 1)) return 0; - len = *p++; + len = skb->data[0]; - if (len >= skb->len) + if (!pskb_may_pull(skb, 1 + len)) return -1; + p = skb->data + 1; + while (len > 0) { switch (*p & X25_FAC_CLASS_MASK) { case X25_FAC_CLASS_A: |