access skb->data safely
we should use skb_header_pointer() and skb_store_bits() to access skb->data to
handle small or non-linear skbs.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
----
net/sched/act_pedit.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
{
struct tcf_pedit *p = a->priv;
int i, munged = 0;
{
struct tcf_pedit *p = a->priv;
int i, munged = 0;
if (!(skb->tc_verd & TC_OK2MUNGE)) {
/* should we set skb->cloned? */
if (!(skb->tc_verd & TC_OK2MUNGE)) {
/* should we set skb->cloned? */
- pptr = skb_network_header(skb);
+ off = skb_network_offset(skb);
struct tc_pedit_key *tkey = p->tcfp_keys;
for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
struct tc_pedit_key *tkey = p->tcfp_keys;
for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
int offset = tkey->off;
if (tkey->offmask) {
int offset = tkey->off;
if (tkey->offmask) {
- if (skb->len > tkey->at) {
- char *j = pptr + tkey->at;
- offset += ((*j & tkey->offmask) >>
- tkey->shift);
- } else {
+ char *d, _d;
+
+ d = skb_header_pointer(skb, off + tkey->at, 1,
+ &_d);
+ if (!d)
+ offset += (*d & tkey->offmask) >> tkey->shift;
- ptr = (u32 *)(pptr+offset);
+ ptr = skb_header_pointer(skb, off + offset, 4, &_data);
+ if (!ptr)
+ goto bad;
/* just do it, baby */
*ptr = ((*ptr & tkey->mask) ^ tkey->val);
/* just do it, baby */
*ptr = ((*ptr & tkey->mask) ^ tkey->val);
+ if (ptr == &_data)
+ skb_store_bits(skb, off + offset, ptr, 4);