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| author | Changli Gao <xiaosuo@gmail.com> | 2010-06-02 04:55:02 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-06-03 03:28:27 -0700 |
| commit | db2c24175d149b55784f7cb2c303622ce962c1ae (patch) | |
| tree | 37c34d4289975bcea43d50bf6eff405f74310db5 /net | |
| parent | 3df95ce948dc8ceef07b49003ab944aa047f2a79 (diff) | |
| download | linux-stable-db2c24175d149b55784f7cb2c303622ce962c1ae.tar.gz linux-stable-db2c24175d149b55784f7cb2c303622ce962c1ae.tar.bz2 linux-stable-db2c24175d149b55784f7cb2c303622ce962c1ae.zip | |
act_pedit: access skb->data safely
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/act_pedit.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c index fdbd0b7bd840..50e3d945e1f4 100644 --- a/net/sched/act_pedit.c +++ b/net/sched/act_pedit.c @@ -125,7 +125,7 @@ static int tcf_pedit(struct sk_buff *skb, struct tc_action *a, { struct tcf_pedit *p = a->priv; int i, munged = 0; - u8 *pptr; + unsigned int off; if (!(skb->tc_verd & TC_OK2MUNGE)) { /* should we set skb->cloned? */ @@ -134,7 +134,7 @@ static int tcf_pedit(struct sk_buff *skb, struct tc_action *a, } } - pptr = skb_network_header(skb); + off = skb_network_offset(skb); spin_lock(&p->tcf_lock); @@ -144,17 +144,17 @@ static int tcf_pedit(struct sk_buff *skb, struct tc_action *a, struct tc_pedit_key *tkey = p->tcfp_keys; for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { - u32 *ptr; + u32 *ptr, _data; 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) goto bad; - } + offset += (*d & tkey->offmask) >> tkey->shift; } if (offset % 4) { @@ -169,9 +169,13 @@ static int tcf_pedit(struct sk_buff *skb, struct tc_action *a, goto bad; } - 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); + if (ptr == &_data) + skb_store_bits(skb, off + offset, ptr, 4); munged++; } |