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| author | Florian Westphal <fw@strlen.de> | 2014-10-23 10:36:07 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-11-19 18:38:25 +0100 |
| commit | 45ebf3641319166e3a6c468eeeac48aa4d6d567d (patch) | |
| tree | e9307f5fd61de9cf9ba963a65f08e0b6ba29da19 | |
| parent | 131172845aa2c804ffa9423455aee585061ea35e (diff) | |
| download | lwn-45ebf3641319166e3a6c468eeeac48aa4d6d567d.tar.gz lwn-45ebf3641319166e3a6c468eeeac48aa4d6d567d.zip | |
netfilter: nfnetlink_log: fix maximum packet length logged to userspace
commit c1e7dc91eed0ed1a51c9b814d648db18bf8fc6e9 upstream.
don't try to queue payloads > 0xffff - NLA_HDRLEN, it does not work.
The nla length includes the size of the nla struct, so anything larger
results in u16 integer overflow.
This patch is similar to
9cefbbc9c8f9abe (netfilter: nfnetlink_queue: cleanup copy_range usage).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | net/netfilter/nfnetlink_log.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 65791530f460..39010fc1e9c0 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -45,7 +45,8 @@ #define NFULNL_NLBUFSIZ_DEFAULT NLMSG_GOODSIZE #define NFULNL_TIMEOUT_DEFAULT 100 /* every second */ #define NFULNL_QTHRESH_DEFAULT 100 /* 100 packets */ -#define NFULNL_COPY_RANGE_MAX 0xFFFF /* max packet size is limited by 16-bit struct nfattr nfa_len field */ +/* max packet size is limited by 16-bit struct nfattr nfa_len field */ +#define NFULNL_COPY_RANGE_MAX (0xFFFF - NLA_HDRLEN) #define PRINTR(x, args...) do { if (net_ratelimit()) \ printk(x, ## args); } while (0); @@ -255,6 +256,8 @@ nfulnl_set_mode(struct nfulnl_instance *inst, u_int8_t mode, case NFULNL_COPY_PACKET: inst->copy_mode = mode; + if (range == 0) + range = NFULNL_COPY_RANGE_MAX; inst->copy_range = min_t(unsigned int, range, NFULNL_COPY_RANGE_MAX); break; @@ -681,8 +684,7 @@ nfulnl_log_packet(struct net *net, break; case NFULNL_COPY_PACKET: - if (inst->copy_range == 0 - || inst->copy_range > skb->len) + if (inst->copy_range > skb->len) data_len = skb->len; else data_len = inst->copy_range; |