Re: WARNING: CPU: 1

From: Arend Van Spriel
Date: Mon Sep 28 2020 - 06:46:16 EST


On 9/28/2020 12:04 PM, Dmitry Vyukov wrote:
On Mon, Sep 28, 2020 at 11:31 AM Arend Van Spriel
<arend.vanspriel@xxxxxxxxxxxx> wrote:

On 9/27/2020 10:47 AM, Dmitry Vyukov wrote:
On Sun, Sep 27, 2020 at 10:38 AM syzbot
<syzbot+3640e696903873858f7e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

Hello,

syzbot found the following issue on:

HEAD commit: 748d1c8a Merge branch 'devlink-Use-nla_policy-to-validate-..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13ac3ec3900000
kernel config: https://syzkaller.appspot.com/x/.config?x=51fb40e67d1e3dec
dashboard link: https://syzkaller.appspot.com/bug?extid=3640e696903873858f7e
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1599be03900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=149fd44b900000

Based on the reproducer, this looks like some wireless bug.
+net/wireless maintainers.

I don't think so looking at this part of the stacktrace:

[ 51.814941] [<ffffffff8465cc95>] macvlan_common_newlink+0xa15/0x1720
[ 51.833542] [<ffffffff84662548>] macvtap_newlink+0x128/0x230
[ 51.858008] [<ffffffff85b68bfe>] rtnl_newlink+0xe5e/0x1780
[ 51.925885] [<ffffffff85b5d32b>] rtnetlink_rcv_msg+0x22b/0xc20

Regards,
Arend

That's the trace on the oldest release and the bisection was diverged
somewhere midway.
You may see this in the bisection log:
https://syzkaller.appspot.com/text?tag=Log&x=1474aaad900000

Initially it crashed with this warning:
all runs: crashed: WARNING in sta_info_insert_rcu

This function is in net/mac80211/sta_info.c.

I see. Thanks for the clarification. It was not really obvious where to dig for information.

Regards,
Arend

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