Re: [PATCH nf-next v4 0/9] nftables: Set implementation for arbitrary concatenation of ranges

[Stefano Brivio <sbrivio@redhat.com>]

Hi Phil,

On Thu, 20 Feb 2020 11:52:41 +0100
Phil Sutter <phil@nwl.cc> wrote:

> Hi Stefano,
> 
> When playing with adding multiple elements, I suddenly noticed a
> disturbance in the force (general protection fault). Here's a
> reproducer:
> 
> | $NFT -f - <<EOF
> | table t {
> |         set s {
> |                 type ipv4_addr . inet_service
> |                 flags interval
> |         }
> | }
> | EOF
> | 
> | $NFT add element t s '{ 10.0.0.1 . 22-25, 10.0.0.1 . 10-20 }'
> | $NFT flush set t s
> | $NFT add element t s '{ 10.0.0.1 . 10-20, 10.0.0.1 . 22-25 }'
> 
> It is pretty reliable, though sometimes needs a second call. Looks like some
> things going on in parallel which shouldn't. Here's a typical last breath:
> 
> [   71.319848] general protection fault, probably for non-canonical address 0x6f6b6e696c2e756e: 0000 [#1] PREEMPT SMP PTI
> [   71.321540] CPU: 3 PID: 1201 Comm: kworker/3:2 Not tainted 5.6.0-rc1-00377-g2bb07f4e1d861 #192
> [   71.322746] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014
> [   71.324430] Workqueue: events nf_tables_trans_destroy_work [nf_tables]
> [   71.325387] RIP: 0010:nft_set_elem_destroy+0xa5/0x110 [nf_tables]

Ouch, thanks for reporting, I'll check in a few hours.

-- 
Stefano