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| author | Florian Westphal <fw@strlen.de> | 2014-10-23 10:36:07 +0200 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2014-11-23 10:55:48 +0100 |
| commit | a7be0fe9a512a966ec6e641f9821d647bc803270 (patch) | |
| tree | 658c075c8a12259a4e03f8fee421a1d903e0bb80 | |
| parent | 6c50e2f9c29f9dc72a3b1af1c6c401b10da96992 (diff) | |
| download | lwn-a7be0fe9a512a966ec6e641f9821d647bc803270.tar.gz lwn-a7be0fe9a512a966ec6e641f9821d647bc803270.zip | |
netfilter: nfnetlink_log: fix maximum packet length logged to userspace
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>
(cherry picked from commit c1e7dc91eed0ed1a51c9b814d648db18bf8fc6e9)
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -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 a5f02eb06c51..ebcbf072bc37 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -41,7 +41,8 @@ #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); @@ -221,6 +222,8 @@ 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; @@ -609,8 +612,7 @@ nfulnl_log_packet(u_int8_t pf, 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; |