| Message ID | 1275491747-29888-1-git-send-email-xiaosuo@gmail.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Changli Gao <xiaosuo@gmail.com> Date: Wed, 2 Jun 2010 23:15:47 +0800 > check unaligned data access > > before accessing data, check if the corresponding address is aligned, and if > not, return -1. > > Signed-off-by: Changli Gao <xiaosuo@gmail.com> The user will find out when he gets warnings in his kernel log messages on platforms where this matters. And, if anything, silently just skipping over things is not acceptable. And imposing a 4-byte alignment could break existing setups that actually work on x86 and powerpc which are platforms that don't have alignment issues. I basically tried to explain to you earlier that I wasn't going to accept patches that try to deal with alignment in any way here in this code, we explicitly and intentionally blindly dereference the data. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 4f52214..309d275 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -102,7 +102,8 @@ static int u32_classify(struct sk_buff *skb, struct tcf_proto *tp, struct tcf_re } stack[TC_U32_MAXDEPTH]; struct tc_u_hnode *ht = (struct tc_u_hnode*)tp->root; - unsigned int off = skb_network_offset(skb); + unsigned int noff = skb_network_offset(skb); + unsigned int off = noff; struct tc_u_knode *n; int sdepth = 0; int off2 = 0; @@ -138,6 +139,8 @@ next_knode: __be32 *data, _data; toff = off + key->off + (off2 & key->offmask); + if ((toff - noff) % 4) + goto out; data = skb_header_pointer(skb, toff, 4, &_data); if (!data) goto out; @@ -188,6 +191,8 @@ check_terminal: if (ht->divisor) { __be32 *data, _data; + if ((off + n->sel.hoff - noff) % 4) + goto out; data = skb_header_pointer(skb, off + n->sel.hoff, 4, &_data); if (!data) @@ -203,6 +208,8 @@ check_terminal: if (n->sel.flags & TC_U32_VAROFFSET) { __be16 *data, _data; + if ((off + n->sel.offoff - noff) % 2) + goto out; data = skb_header_pointer(skb, off + n->sel.offoff, 2, &_data);
check unaligned data access before accessing data, check if the corresponding address is aligned, and if not, return -1. Signed-off-by: Changli Gao <xiaosuo@gmail.com> ---- net/sched/cls_u32.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html