diff options
| author | Amir Vadai <amir@vadai.me> | 2016-11-28 12:56:40 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-12-13 16:57:11 +0100 |
| commit | f277a1310514bff1c5f05c93b33bd7caf2e119fb (patch) | |
| tree | e09c801f36e92c31a9127472451c70845b163830 | |
| parent | c20932ae0d412f1aabf3514891cdd6ae6a08ae01 (diff) | |
net/sched: pedit: make sure that offset is valid
[ Upstream commit 95c2027bfeda21a28eb245121e6a249f38d0788e ]
Add a validation function to make sure offset is valid:
1. Not below skb head (could happen when offset is negative).
2. Validate both 'offset' and 'at'.
Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | net/sched/act_pedit.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c index 7ed78c9e505c..3f385130e9c0 100644 --- a/net/sched/act_pedit.c +++ b/net/sched/act_pedit.c @@ -124,6 +124,17 @@ static int tcf_pedit_cleanup(struct tc_action *a, int bind) return 0; } +static bool offset_valid(struct sk_buff *skb, int offset) +{ + if (offset > 0 && offset > skb->len) + return false; + + if (offset < 0 && -offset > skb_headroom(skb)) + return false; + + return true; +} + static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { @@ -150,6 +161,11 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, if (tkey->offmask) { char *d, _d; + if (!offset_valid(skb, off + tkey->at)) { + pr_info("tc filter pedit 'at' offset %d out of bounds\n", + off + tkey->at); + goto bad; + } d = skb_header_pointer(skb, off + tkey->at, 1, &_d); if (!d) @@ -162,10 +178,10 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, " offset must be on 32 bit boundaries\n"); goto bad; } - if (offset > 0 && offset > skb->len) { - pr_info("tc filter pedit" - " offset %d can't exceed pkt length %d\n", - offset, skb->len); + + if (!offset_valid(skb, off + offset)) { + pr_info("tc filter pedit offset %d out of bounds\n", + offset); goto bad; } |