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>
- priv->cost = div_u64(priv->limit.nsecs, priv->limit.rate);
+ priv->cost = div64_u64(priv->limit.nsecs, priv->limit.rate);
const struct nft_pktinfo *pkt)
{
struct nft_limit *priv = nft_expr_priv(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;
if (nft_limit_eval(priv, cost))
regs->verdict.code = NFT_BREAK;