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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 9 Dec 2019 11:46:37 +0100
Message-ID: <CAMuHMdXKNMgAQHAE4f-0=srAZtDNUPB6Hmdm277XTgukrtiJ4Q@mail.gmail.com>
Subject: Re: [GIT] Networking
To:     David Miller <davem@redhat.com>,
        Yoshiki Komachi <komachi.yoshiki@gmail.com>
Cc:     "torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        netdev <netdev@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi David, Komachi-san,

On Sun, Dec 8, 2019 at 10:25 AM David Miller <davem@redhat.com> wrote:
> Yoshiki Komachi (1):
>       cls_flower: Fix the behavior using port ranges with hw-offload

I have bisected the below boot warning on m68k/ARAnyM to commit
8ffb055beae58574 ("cls_flower: Fix the behavior using port ranges with
hw-offload").  Reverting the commit on top of v5.5-rc1 fixes the issue.

WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x54/0x100
refcount_t: underflow; use-after-free.
Modules linked in:
CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted
5.4.0-atari-10298-g8ffb055beae58574 #223
Stack from 00c31e88:
        00c31e88 0038237c 00023d0a 00395a16 0000001c 00000009 00a67c80 00023d4e
        00395a16 0000001c 001a7c30 00000009 00000000 00c31ed0 00000001 00000000
        04208040 0000000a 00395a51 00c31ef0 00c30000 001a7c30 00395a16 0000001c
        00000009 00395a51 0026b1bc 0032253c 00000003 003224f8 0026c2be 00000001
        0032253c 00000000 00a67c80 00241d8c 00a67c80 00000000 00000200 000ab192
        0004859e 00a67c80 0000000a 003facd8 003f5b90 002f2b46 003facd8 002f2dfe
Call Trace: [<00023d0a>] __warn+0xb2/0xb4
 [<00023d4e>] warn_slowpath_fmt+0x42/0x64
 [<001a7c30>] refcount_warn_saturate+0x54/0x100
 [<001a7c30>] refcount_warn_saturate+0x54/0x100
 [<0026b1bc>] refcount_sub_and_test.constprop.73+0x38/0x3e
 [<0026c2be>] ipv4_dst_destroy+0x24/0x42
 [<00241d8c>] dst_destroy+0x40/0xae
 [<000ab192>] kfree+0x0/0x3e
 [<0004859e>] rcu_process_callbacks+0x9a/0x9c
 [<002f2b46>] __do_softirq+0x146/0x182
 [<002f2dfe>] schedule+0x0/0xb4
 [<00035e76>] kthread_parkme+0x0/0x10
 [<000359be>] __init_completion+0x0/0x20
 [<00038308>] smpboot_thread_fn+0x0/0x100
 [<00035fda>] kthread_should_stop+0x0/0x12
 [<00035fce>] kthread_should_park+0x0/0xc
 [<00025b9c>] run_ksoftirqd+0x12/0x20
 [<00038402>] smpboot_thread_fn+0xfa/0x100
 [<00024888>] do_exit+0x0/0x6d4
 [<0003f590>] complete+0x0/0x34
 [<00036594>] kthread+0xb2/0xbc
 [<000359be>] __init_completion+0x0/0x20
 [<000364e2>] kthread+0x0/0xbc
 [<00002a1c>] ret_from_kernel_thread+0xc/0x14
---[ end trace 126b6dd25f47053b ]---

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds