diff options
| author | Phil Sutter <phil@nwl.cc> | 2023-10-17 11:39:06 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-10-18 11:09:55 +0100 |
| commit | c4eee56e14fe001e1cff54f0b438a5e2d0dd7454 (patch) | |
| tree | 65a716224c59aa46608692d49ff871b34bb5edd0 /net/core | |
| parent | 37fb1c81d210a5185c1f5399a0801719bba7f7c9 (diff) | |
net: skb_find_text: Ignore patterns extending past 'to'
Assume that caller's 'to' offset really represents an upper boundary for
the pattern search, so patterns extending past this offset are to be
rejected.
The old behaviour also was kind of inconsistent when it comes to
fragmentation (or otherwise non-linear skbs): If the pattern started in
between 'to' and 'from' offsets but extended to the next fragment, it
was not found if 'to' offset was still within the current fragment.
Test the new behaviour in a kselftest using iptables' string match.
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: f72b948dcbb8 ("[NET]: skb_find_text ignores to argument")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/skbuff.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0401f40973a5..975c9a6ffb4a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4267,6 +4267,7 @@ static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, unsigned int to, struct ts_config *config) { + unsigned int patlen = config->ops->get_pattern_len(config); struct ts_state state; unsigned int ret; @@ -4278,7 +4279,7 @@ unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, skb_prepare_seq_read(skb, from, to, TS_SKB_CB(&state)); ret = textsearch_find(config, &state); - return (ret <= to - from ? ret : UINT_MAX); + return (ret + patlen <= to - from ? ret : UINT_MAX); } EXPORT_SYMBOL(skb_find_text); |