[PATCH nf-next] netfilter: log: Check param to avoid overflow in nf_log_set

[fgao]

From: Gao Feng <f...@ikuai8.com>

The nf_log_set is an interface function, so it should do the strict sanity
check of parameters. Add  one sanity check for pf, it could not exceed
NFPROTO_NUMPROTO, and print error log when pf is invalid.

Signed-off-by: Gao Feng <f...@ikuai8.com>
---
 net/netfilter/nf_log.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index aa5847a..02ce0b9 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -43,8 +43,10 @@ void nf_log_set(struct net *net, u_int8_t pf, const struct 
nf_logger *logger)
 {
        const struct nf_logger *log;
 
-       if (pf == NFPROTO_UNSPEC)
+       if (pf == NFPROTO_UNSPEC || pf >= NFPROTO_NUMPROTO) {
+               pr_err("Wrong pf(%d) for nf log", pf);
                return;
+       }
 
        mutex_lock(&nf_log_mutex);
        log = nft_log_dereference(net->nf.nf_loggers[pf]);
-- 
1.9.1