3.16.42-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Liping Zhang <zlpnobody@xxxxxxxxx>
commit 5ce6b04ce96896e8a79e6f60740ced911eaac7a4 upstream.
First, log prefix will be truncated to NF_LOG_PREFIXLEN-1, i.e. 127,
at nf_log_packet(), so the extra part is useless.
Second, after adding a log rule with a very very long prefix, we will
fail to dump the nft rules after this _special_ one, but acctually,
they do exist. For example:
# name_65000=$(printf "%0.sQ" {1..65000})
# nft add rule filter output log prefix "$name_65000"
# nft add rule filter output counter
# nft add rule filter output counter
# nft list chain filter output
table ip filter {
chain output {
type filter hook output priority 0; policy accept;
}
}
So now, restrict the log prefix length to NF_LOG_PREFIXLEN-1.
Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Liping Zhang <zlpnobody@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
include/net/netfilter/nf_log.h | 2 ++
net/netfilter/nf_log.c | 1 -
net/netfilter/nft_log.c | 3 ++-
3 files changed, 4 insertions(+), 2 deletions(-)
--- a/include/net/netfilter/nf_log.h
+++ b/include/net/netfilter/nf_log.h
@@ -12,6 +12,8 @@
#define NF_LOG_UID 0x08 /* Log UID owning local socket */
#define NF_LOG_MASK 0x0f
+#define NF_LOG_PREFIXLEN 128
+
#define NF_LOG_TYPE_LOG 0x01
#define NF_LOG_TYPE_ULOG 0x02
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -13,7 +13,6 @@
/* Internal logging interface, which relies on the real
LOG target modules */
-#define NF_LOG_PREFIXLEN 128
#define NFLOGGER_NAME_LEN 64
static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
--- a/net/netfilter/nft_log.c
+++ b/net/netfilter/nft_log.c
@@ -38,7 +38,8 @@ static void nft_log_eval(const struct nf
static const struct nla_policy nft_log_policy[NFTA_LOG_MAX + 1] = {
[NFTA_LOG_GROUP] = { .type = NLA_U16 },
- [NFTA_LOG_PREFIX] = { .type = NLA_STRING },
+ [NFTA_LOG_PREFIX] = { .type = NLA_STRING,
+ .len = NF_LOG_PREFIXLEN - 1 },
[NFTA_LOG_SNAPLEN] = { .type = NLA_U32 },
[NFTA_LOG_QTHRESHOLD] = { .type = NLA_U16 },
};