Hi Stefano,
On Sun, 26 May 2019, Stefano Brivio wrote:
> If a fresh array block is allocated during resize, the current in-memory
> set size should be increased by the size of the block, not replaced by it.
>
> Before the fix, adding entries to a hash set type, leading to a table
> resize, caused an inconsistent memory size to be reported. This becomes
> more obvious when swapping sets with similar sizes:
>
> # cat hash_ip_size.sh
> #!/bin/sh
> FAIL_RETRIES=10
>
> tries=0
> while [ ${tries} -lt ${FAIL_RETRIES} ]; do
> ipset create t1 hash:ip
> for i in `seq 1 4345`; do
> ipset add t1 1.2.$((i / 255)).$((i % 255))
> done
> t1_init="$(ipset list t1|sed -n 's/Size in memory: \(.*\)/\1/p')"
>
> ipset create t2 hash:ip
> for i in `seq 1 4360`; do
> ipset add t2 1.2.$((i / 255)).$((i % 255))
> done
> t2_init="$(ipset list t2|sed -n 's/Size in memory: \(.*\)/\1/p')"
>
> ipset swap t1 t2
> t1_swap="$(ipset list t1|sed -n 's/Size in memory: \(.*\)/\1/p')"
> t2_swap="$(ipset list t2|sed -n 's/Size in memory: \(.*\)/\1/p')"
>
> ipset destroy t1
> ipset destroy t2
> tries=$((tries + 1))
>
> if [ ${t1_init} -lt 10000 ] || [ ${t2_init} -lt 10000 ]; then
> echo "FAIL after ${tries} tries:"
> echo "T1 size ${t1_init}, after swap ${t1_swap}"
> echo "T2 size ${t2_init}, after swap ${t2_swap}"
> exit 1
> fi
> done
> echo "PASS"
> # echo -n 'func hash_ip4_resize +p' >
> /sys/kernel/debug/dynamic_debug/control
> # ./hash_ip_size.sh
> [ 2035.018673] attempt to resize set t1 from 10 to 11, t 00000000fe6551fa
> [ 2035.078583] set t1 resized from 10 (00000000fe6551fa) to 11
> (00000000172a0163)
> [ 2035.080353] Table destroy by resize 00000000fe6551fa
> FAIL after 4 tries:
> T1 size 9064, after swap 71128
> T2 size 71128, after swap 9064
>
> Reported-by: NOYB <[email protected]>
> Fixes: 9e41f26a505c ("netfilter: ipset: Count non-static extension memory for
> userspace")
> Signed-off-by: Stefano Brivio <[email protected]>
Excellent, thanks! Patch is applied in ipset git tree and a new release is
on the way.
Best regards,
Jozsef
> ---
> net/netfilter/ipset/ip_set_hash_gen.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/netfilter/ipset/ip_set_hash_gen.h
> b/net/netfilter/ipset/ip_set_hash_gen.h
> index 01d51f775f12..623e0d675725 100644
> --- a/net/netfilter/ipset/ip_set_hash_gen.h
> +++ b/net/netfilter/ipset/ip_set_hash_gen.h
> @@ -625,7 +625,7 @@ mtype_resize(struct ip_set *set, bool retried)
> goto cleanup;
> }
> m->size = AHASH_INIT_SIZE;
> - extsize = ext_size(AHASH_INIT_SIZE, dsize);
> + extsize += ext_size(AHASH_INIT_SIZE, dsize);
> RCU_INIT_POINTER(hbucket(t, key), m);
> } else if (m->pos >= m->size) {
> struct hbucket *ht;
> --
> 2.20.1
>
>
-
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