Re: [PATCH nf] netfilter: nft_numgen: disable preempt to access per-cpu data

[Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>]

On Wed, May 18, 2022 at 04:03:00PM +0200, Pablo Neira Ayuso wrote:
> On Mon, May 16, 2022 at 10:55:52AM +0200, Pablo Neira Ayuso wrote:
> > [233241.951068] BUG: using smp_processor_id() in preemptible [00000000] code: nginx/2725
> > [233241.951220] caller is nft_ng_random_eval+0x24/0x54 [nft_numgen]
> > [233241.951225] CPU: 2 PID: 2725 Comm: nginx Tainted: G           OE 5.16.0-0.bpo.4-amd64 #1  Debian 5.16.12-1~bpo11+1
> > [233241.951227] Hardware name: Supermicro SYS-5039MC-H8TRF/X11SCD-F, BIOS 1.7 11/23/2021
> > [233241.951228] Call Trace:
> > [233241.951231]  <TASK>
> > [233241.951233]  dump_stack_lvl+0x48/0x5e
> > [233241.951236]  check_preemption_disabled+0xde/0xe0
> > [233241.951239]  nft_ng_random_eval+0x24/0x54 [nft_numgen]
> 
> For the record, patch applied to nf.git

I don't think my patch is correct, I should disable_bh instead.

I kept it back.