netfilter: nft_counter: Synchronize nft_counter_reset() against reader.

nft_counter_reset() resets the counter by subtracting the previously
retrieved value from the counter. This is a write operation on the
counter and as such it requires to be performed with a write sequence of
nft_counter_seq to serialize against its possible reader.

Update the packets/ bytes within write-sequence of nft_counter_seq.

Fixes: d84701ecbc ("netfilter: nft_counter: rework atomic dump and reset")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Sebastian Andrzej Siewior 2024-08-20 09:54:31 +02:00 committed by Pablo Neira Ayuso
parent 1eacdd71b3
commit a0b39e2dc7

View File

@ -107,11 +107,16 @@ static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
struct nft_counter *total)
{
struct nft_counter *this_cpu;
seqcount_t *myseq;
local_bh_disable();
this_cpu = this_cpu_ptr(priv->counter);
myseq = this_cpu_ptr(&nft_counter_seq);
write_seqcount_begin(myseq);
this_cpu->packets -= total->packets;
this_cpu->bytes -= total->bytes;
write_seqcount_end(myseq);
local_bh_enable();
}