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authorLiping Zhang <liping.zhang@spreadtrum.com>2016-09-27 20:49:19 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2016-10-04 08:59:03 +0200
commit2fa46c130193300f06e68727ae98ec9f6184cad4 (patch)
treea5e44867923127f285cb7acdcd40f1298a5bdcd9 /net/netfilter/nft_limit.c
parentdbb5918cb333dfeb8897f8e8d542661d2ff5b9a0 (diff)
netfilter: nft_limit: fix divided by zero panic
After I input the following nftables rule, a panic happened on my system: # nft add rule filter OUTPUT limit rate 0xf00000000 bytes/second divide error: 0000 [#1] SMP [ ... ] RIP: 0010:[<ffffffffa059035e>] [<ffffffffa059035e>] nft_limit_pkt_bytes_eval+0x2e/0xa0 [nft_limit] Call Trace: [<ffffffffa05721bb>] nft_do_chain+0xfb/0x4e0 [nf_tables] [<ffffffffa044f236>] ? nf_nat_setup_info+0x96/0x480 [nf_nat] [<ffffffff81753767>] ? ipt_do_table+0x327/0x610 [<ffffffffa044f677>] ? __nf_nat_alloc_null_binding+0x57/0x80 [nf_nat] [<ffffffffa058b21f>] nft_ipv4_output+0xaf/0xd0 [nf_tables_ipv4] [<ffffffff816f4aa2>] nf_iterate+0x62/0x80 [<ffffffff816f4b33>] nf_hook_slow+0x73/0xd0 [<ffffffff81703d0d>] __ip_local_out+0xcd/0xe0 [<ffffffff81701d90>] ? ip_forward_options+0x1b0/0x1b0 [<ffffffff81703d3c>] ip_local_out+0x1c/0x40 This is because divisor is 64-bit, but we treat it as a 32-bit integer, then 0xf00000000 becomes zero, i.e. divisor becomes 0. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nft_limit.c')
-rw-r--r--net/netfilter/nft_limit.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c
index 070b98938e02..c6baf412236d 100644
--- a/net/netfilter/nft_limit.c
+++ b/net/netfilter/nft_limit.c
@@ -145,7 +145,7 @@ static int nft_limit_pkts_init(const struct nft_ctx *ctx,
if (err < 0)
return err;
- priv->cost = div_u64(priv->limit.nsecs, priv->limit.rate);
+ priv->cost = div64_u64(priv->limit.nsecs, priv->limit.rate);
return 0;
}
@@ -170,7 +170,7 @@ static void nft_limit_pkt_bytes_eval(const struct nft_expr *expr,
const struct nft_pktinfo *pkt)
{
struct nft_limit *priv = nft_expr_priv(expr);
- u64 cost = div_u64(priv->nsecs * pkt->skb->len, priv->rate);
+ u64 cost = div64_u64(priv->nsecs * pkt->skb->len, priv->rate);
if (nft_limit_eval(priv, cost))
regs->verdict.code = NFT_BREAK;