WARNING in batadv_iv_send_outstanding_bat_ogm_packet

WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[Tetsuo Handa]

syzbot is hitting

  WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface)

at batadv_iv_ogm_emit() [1].

This WARN_ON() was added by commit ef0a937f7a1450d3 ("batman-adv: consider
outgoing interface in OGM sending") but it is unclear why it needs to use
WARN_ON(). Is this fatal error worth crashing the kernel?

Please consider replacing with pr_err() etc. like commit b4142fc4d52d051d
("drm/vkms: fix misuse of WARN_ON") does if this is not a kernel bug.

[1] https://syzkaller.appspot.com/bug?id=9dc0c4cd70ad72df352243e887fd7e18901e7cee

[PATCH] batman-adv: don't warn when enslaving hard interface failed

[Tetsuo Handa]

syzbot is hitting

  WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface)

at batadv_iv_ogm_emit() [1], for forw_packet->if_outgoing->soft_iface
can remain NULL if batadv_hardif_enable_interface() failed due to e.g.
memory allocation fault injection.

Link: https://syzkaller.appspot.com/bug?id=9dc0c4cd70ad72df352243e887fd7e18901e7cee [1]
Reported-by: syzbot <syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com>
Tested-by: syzbot <syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: ef0a937f7a1450d3 ("batman-adv: consider outgoing interface in OGM sending")
---
 net/batman-adv/bat_iv_ogm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 789f257be24f..d24853c16ea5 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -409,6 +409,9 @@ static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 	if (WARN_ON(!forw_packet->if_outgoing))
 		return;
 
+	if (!forw_packet->if_outgoing->soft_iface)
+		return;
+
 	if (WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface))
 		return;
 
-- 
2.18.4

Re: [PATCH] batman-adv: don't warn when enslaving hard interface failed

[Sven Eckelmann]

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On Sunday, 6 June 2021 16:28:17 CEST Tetsuo Handa wrote:
> syzbot is hitting
> 
>   WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface)
> 
> at batadv_iv_ogm_emit() [1], for forw_packet->if_outgoing->soft_iface
> can remain NULL if batadv_hardif_enable_interface() failed due to e.g.
> memory allocation fault injection.

Cannot apply this because following (conflicting) is already queued up in 
batadv/net:  
https://git.open-mesh.org/linux-merge.git/blobdiff/b741596468b010af2846b75f5e75a842ce344a6e..9f460ae31c4435fd022c443a6029352217a16ac1:/net/batman-adv/bat_iv_ogm.c

    Applying patch #18340 using 'git am -s'
    Description: batman-adv: don't warn when enslaving hard interface failed
    Applying: batman-adv: don't warn when enslaving hard interface failed
    error: patch failed: net/batman-adv/bat_iv_ogm.c:409
    error: net/batman-adv/bat_iv_ogm.c: patch does not apply
    Patch failed at 0001 batman-adv: don't warn when enslaving hard interface failed
    hint: Use 'git am --show-current-patch=diff' to see the failed patch
    When you have resolved this problem, run "git am --continue".
    If you prefer to skip this patch, run "git am --skip" instead.
    To restore the original branch and stop patching, run "git am --abort".
    'git am' failed with exit status 128

Please rebase your patch in case it is really needed.

And the explanation you give seems to be bogus. Or am I missing some error 
handling in batadv_hardif_enable_interface [1]?

Kind regards,
	Sven

[1] https://git.open-mesh.org/linux-merge.git/blob/refs/heads/batadv/net-next:/net/batman-adv/hard-interface.c

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Re: [PATCH] batman-adv: don't warn when enslaving hard interface failed

[Tetsuo Handa]

On 2021/06/06 23:35, Sven Eckelmann wrote:
> Please rebase your patch in case it is really needed.

Oh, I didn't know you already applied that change, for that commit is
not yet visible from linux-next.git as of next-20210604.

> 
> And the explanation you give seems to be bogus. Or am I missing some error 
> handling in batadv_hardif_enable_interface [1]?

I told syzbot to try https://syzkaller.appspot.com/text?tag=Patch&x=100b083fd00000
and the response ( https://syzkaller.appspot.com/text?tag=CrashLog&x=1456f0ffd00000 ) was

   batman_adv: forw_packet->if_outgoing->soft_iface=0000000000000000 forw_packet->if_incoming->soft_iface=0000000039fa85b7

indicating that if_outgoing->soft_iface was NULL, and there was a memory allocation
fault injection immediately before this result.

Since if_outgoing->soft_iface becomes non-NULL if batadv_hardif_enable_interface()
succeeds, this situation indicates that batadv_hardif_enable_interface() failure
caused forw_packet->if_outgoing->soft_iface to remain NULL.

> 
> Kind regards,
> 	Sven
> 
> [1] https://git.open-mesh.org/linux-merge.git/blob/refs/heads/batadv/net-next:/net/batman-adv/hard-interface.c
> 

Re: [PATCH] batman-adv: don't warn when enslaving hard interface failed

[Sven Eckelmann]

[-- Attachment #1: Type: text/plain, Size: 1324 bytes --]

On Sunday, 6 June 2021 17:48:25 CEST Tetsuo Handa wrote:
> > And the explanation you give seems to be bogus. Or am I missing some error 
> > handling in batadv_hardif_enable_interface [1]?
> 
> I told syzbot to try https://syzkaller.appspot.com/text?tag=Patch&x=100b083fd00000
> and the response ( https://syzkaller.appspot.com/text?tag=CrashLog&x=1456f0ffd00000 ) was
> 
>    batman_adv: forw_packet->if_outgoing->soft_iface=0000000000000000 forw_packet->if_incoming->soft_iface=0000000039fa85b7
> 
> indicating that if_outgoing->soft_iface was NULL, and there was a memory allocation
> fault injection immediately before this result.
> 
> Since if_outgoing->soft_iface becomes non-NULL if batadv_hardif_enable_interface()
> succeeds, this situation indicates that batadv_hardif_enable_interface() failure
> caused forw_packet->if_outgoing->soft_iface to remain NULL.

Ok, then I misread the commit message. I've understood is as "soft_iface" 
allocation failed (which doesn't happen here anymore) in 
batadv_hardif_enable_interface. But you meant that was that hard_iface->soft_iface is 
set to the correct value, the OGM transmission is started up by batadv_iv_ogm_schedule_buff
but soft_iface is changed back immediately in batadv_hardif_enable_interface because
netdev_master_upper_dev_link failed.

Kind regards,
	Sven

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Re: WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[Dmitry Vyukov]

On Wed, Sep 16, 2020 at 7:43 AM Anant Thazhemadam
<anant.thazhemadam@gmail.com> wrote:
>
>
> On 16/09/20 10:25 am, Dmitry Vyukov wrote:
> > On Tue, Sep 15, 2020 at 8:34 PM Anant Thazhemadam
> > <anant.thazhemadam@gmail.com> wrote:
> >> On Monday, October 14, 2019 at 2:25:08 AM UTC+5:30 syzbot wrote:
> >>> Hello,
> >>>
> >>> syzbot found the following crash on:
> >>>
> >>> HEAD commit: da940012 Merge tag 'char-misc-5.4-rc3' of git://git.kernel..
> >>> git tree: upstream
> >>> console output: https://syzkaller.appspot.com/x/log.txt?x=13ffd808e00000
> >>> kernel config: https://syzkaller.appspot.com/x/.config?x=2d2fd92a28d3e50
> >>> dashboard link: https://syzkaller.appspot.com/bug?extid=c0b807de416427ff3dd1
> >>> compiler: clang version 9.0.0 (/home/glider/llvm/clang
> >>> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141ffd77600000
> >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11edd580e00000
> >>>
> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> >>> Reported-by: syzbot+c0b807...@syzkaller.appspotmail.com
> >>>
> >>> ------------[ cut here ]------------
> >>> WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382
> >>> batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
> >>> WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382
> >>> batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770
> >>> net/batman-adv/bat_iv_ogm.c:1663
> >>> Kernel panic - not syncing: panic_on_warn set ...
> >>> CPU: 1 PID: 30 Comm: kworker/u4:2 Not tainted 5.4.0-rc2+ #0
> >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> >>> Google 01/01/2011
> >>> Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
> >>> Call Trace:
> >>> __dump_stack lib/dump_stack.c:77 [inline]
> >>> dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
> >>> panic+0x264/0x7a9 kernel/panic.c:221
> >>> __warn+0x20e/0x210 kernel/panic.c:582
> >>> report_bug+0x1b6/0x2f0 lib/bug.c:195
> >>> fixup_bug arch/x86/kernel/traps.c:179 [inline]
> >>> do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
> >>> do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
> >>> invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
> >>> RIP: 0010:batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
> >>> RIP: 0010:batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770
> >>> net/batman-adv/bat_iv_ogm.c:1663
> >>> Code: 66 05 00 eb 05 e8 9c 48 23 fa 48 83 c4 68 5b 41 5c 41 5d 41 5e 41 5f
> >>> 5d c3 e8 88 48 23 fa 0f 0b e9 34 ff ff ff e8 7c 48 23 fa <0f> 0b e9 28 ff
> >>> ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c c1 f9 ff
> >>> RSP: 0018:ffff8880a9abfc48 EFLAGS: 00010293
> >>> RAX: ffffffff874fe8a4 RBX: ffff888094160870 RCX: ffff8880a9ab2080
> >>> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
> >>> RBP: ffff8880a9abfcd8 R08: ffffffff874fe28e R09: ffffed10123e6969
> >>> R10: ffffed10123e6969 R11: 0000000000000000 R12: ffff888091f34000
> >>> R13: dffffc0000000000 R14: ffff8880a80c5000 R15: ffff8880a4481400
> >>> process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269
> >>> worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
> >>> kthread+0x332/0x350 kernel/kthread.c:255
> >>> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> >>> Kernel Offset: disabled
> >>> Rebooting in 86400 seconds..
> >>>
> >>>
> >>> ---
> >>> This bug is generated by a bot. It may contain errors.
> >>> See https://goo.gl/tpsmEJ for more information about syzbot.
> >>> syzbot engineers can be reached at syzk...@googlegroups.com.
> >>>
> >>> syzbot will keep track of this bug report. See:
> >>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >>> syzbot can test patches for this bug, for details see:
> >>> https://goo.gl/tpsmEJ#testing-patches
> >>
> >> For this bug, syzbot does not seem to be able to build the kernel anymore.
> >> Can bugs like these be considered and closed as invalid?
> >>
> >> Thanks,
> >> Anant
> > Hi Anant,
> >
> > +syzkaler, lkml (nobody is generally reading syzkaller-bugs).
> >
> > What do you mean by "not able to build a kernel for this bug"?
> > Building a kernel is not related to a particular bug. It's the same
> > for all bugs...
>
> Hi,
>
> I thought this might be a query that's better suited for the syzkaller groups,
> and hence posted it on there.
>
> I wanted to check if this bug was still present and relevant, so I tried to check
> by sending a syz test request for the upstream kernel (the dashboard shows
> that the error was found in the upstream kernel).
>
> However, I was notified later that the build/boot had failed.
> Feel free to correct me if I'm wrong, but I doubt that the reason build/boot
> had failed, was because of the bug itself (the error report is visible on the
> bug's dashboard page itself).
>
> I wanted to know what was the typical protocol in cases like this. Would this be
> a valid reason enough to close the bug as invalid? Or is there something else
> that can be done, to indicate that the upstream kernel doesn't even build/boot
> for this bug to be tested anymore?
> If nothing else, how else can I try and get syzbot to test if this bug still exists or
> not?
>
> Thanks,
> Anant


I see that config is not building anymore:

BTF: .tmp_vmlinux.btf: pahole version v1.9 is too old, need at least v1.16
Failed to generate BTF for vmlinux
Try to disable CONFIG_DEBUG_INFO_BTF
Makefile:1162: recipe for target 'vmlinux' failed

This is not anyhow top the bug itself, if it still happens or not. So
this does not look like a valid reason to close the bug.

There are two options:
1. Attach a patch for testing that disables CONFIG_DEBUG_INFO_BTF
(e.g. delete it, or make it dependent on some disabled config, not
sure what's the easiest working option).
2. Test locally with the config disabled.

Re: WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[Anant Thazhemadam]

On 16/09/20 10:25 am, Dmitry Vyukov wrote:
> On Tue, Sep 15, 2020 at 8:34 PM Anant Thazhemadam
> <anant.thazhemadam@gmail.com> wrote:
>> On Monday, October 14, 2019 at 2:25:08 AM UTC+5:30 syzbot wrote:
>>> Hello,
>>>
>>> syzbot found the following crash on:
>>>
>>> HEAD commit: da940012 Merge tag 'char-misc-5.4-rc3' of git://git.kernel..
>>> git tree: upstream
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=13ffd808e00000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=2d2fd92a28d3e50
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=c0b807de416427ff3dd1
>>> compiler: clang version 9.0.0 (/home/glider/llvm/clang
>>> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
>>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141ffd77600000
>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11edd580e00000
>>>
>>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>>> Reported-by: syzbot+c0b807...@syzkaller.appspotmail.com
>>>
>>> ------------[ cut here ]------------
>>> WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382
>>> batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
>>> WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382
>>> batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770
>>> net/batman-adv/bat_iv_ogm.c:1663
>>> Kernel panic - not syncing: panic_on_warn set ...
>>> CPU: 1 PID: 30 Comm: kworker/u4:2 Not tainted 5.4.0-rc2+ #0
>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>>> Google 01/01/2011
>>> Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
>>> Call Trace:
>>> __dump_stack lib/dump_stack.c:77 [inline]
>>> dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
>>> panic+0x264/0x7a9 kernel/panic.c:221
>>> __warn+0x20e/0x210 kernel/panic.c:582
>>> report_bug+0x1b6/0x2f0 lib/bug.c:195
>>> fixup_bug arch/x86/kernel/traps.c:179 [inline]
>>> do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
>>> do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
>>> invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
>>> RIP: 0010:batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
>>> RIP: 0010:batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770
>>> net/batman-adv/bat_iv_ogm.c:1663
>>> Code: 66 05 00 eb 05 e8 9c 48 23 fa 48 83 c4 68 5b 41 5c 41 5d 41 5e 41 5f
>>> 5d c3 e8 88 48 23 fa 0f 0b e9 34 ff ff ff e8 7c 48 23 fa <0f> 0b e9 28 ff
>>> ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c c1 f9 ff
>>> RSP: 0018:ffff8880a9abfc48 EFLAGS: 00010293
>>> RAX: ffffffff874fe8a4 RBX: ffff888094160870 RCX: ffff8880a9ab2080
>>> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
>>> RBP: ffff8880a9abfcd8 R08: ffffffff874fe28e R09: ffffed10123e6969
>>> R10: ffffed10123e6969 R11: 0000000000000000 R12: ffff888091f34000
>>> R13: dffffc0000000000 R14: ffff8880a80c5000 R15: ffff8880a4481400
>>> process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269
>>> worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
>>> kthread+0x332/0x350 kernel/kthread.c:255
>>> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>>> Kernel Offset: disabled
>>> Rebooting in 86400 seconds..
>>>
>>>
>>> ---
>>> This bug is generated by a bot. It may contain errors.
>>> See https://goo.gl/tpsmEJ for more information about syzbot.
>>> syzbot engineers can be reached at syzk...@googlegroups.com.
>>>
>>> syzbot will keep track of this bug report. See:
>>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>>> syzbot can test patches for this bug, for details see:
>>> https://goo.gl/tpsmEJ#testing-patches
>>
>> For this bug, syzbot does not seem to be able to build the kernel anymore.
>> Can bugs like these be considered and closed as invalid?
>>
>> Thanks,
>> Anant
> Hi Anant,
>
> +syzkaler, lkml (nobody is generally reading syzkaller-bugs).
>
> What do you mean by "not able to build a kernel for this bug"?
> Building a kernel is not related to a particular bug. It's the same
> for all bugs...

Hi,

I thought this might be a query that's better suited for the syzkaller groups,
and hence posted it on there.

I wanted to check if this bug was still present and relevant, so I tried to check
by sending a syz test request for the upstream kernel (the dashboard shows
that the error was found in the upstream kernel).

However, I was notified later that the build/boot had failed.
Feel free to correct me if I'm wrong, but I doubt that the reason build/boot
had failed, was because of the bug itself (the error report is visible on the
bug's dashboard page itself).

I wanted to know what was the typical protocol in cases like this. Would this be
a valid reason enough to close the bug as invalid? Or is there something else
that can be done, to indicate that the upstream kernel doesn't even build/boot
for this bug to be tested anymore?
If nothing else, how else can I try and get syzbot to test if this bug still exists or
not?

Thanks,
Anant

Re: WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[Dmitry Vyukov]

On Tue, Sep 15, 2020 at 8:34 PM Anant Thazhemadam
<anant.thazhemadam@gmail.com> wrote:
> On Monday, October 14, 2019 at 2:25:08 AM UTC+5:30 syzbot wrote:
>>
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit: da940012 Merge tag 'char-misc-5.4-rc3' of git://git.kernel..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=13ffd808e00000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=2d2fd92a28d3e50
>> dashboard link: https://syzkaller.appspot.com/bug?extid=c0b807de416427ff3dd1
>> compiler: clang version 9.0.0 (/home/glider/llvm/clang
>> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141ffd77600000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11edd580e00000
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+c0b807...@syzkaller.appspotmail.com
>>
>> ------------[ cut here ]------------
>> WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382
>> batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
>> WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382
>> batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770
>> net/batman-adv/bat_iv_ogm.c:1663
>> Kernel panic - not syncing: panic_on_warn set ...
>> CPU: 1 PID: 30 Comm: kworker/u4:2 Not tainted 5.4.0-rc2+ #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>> Google 01/01/2011
>> Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
>> Call Trace:
>> __dump_stack lib/dump_stack.c:77 [inline]
>> dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
>> panic+0x264/0x7a9 kernel/panic.c:221
>> __warn+0x20e/0x210 kernel/panic.c:582
>> report_bug+0x1b6/0x2f0 lib/bug.c:195
>> fixup_bug arch/x86/kernel/traps.c:179 [inline]
>> do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
>> do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
>> invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
>> RIP: 0010:batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
>> RIP: 0010:batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770
>> net/batman-adv/bat_iv_ogm.c:1663
>> Code: 66 05 00 eb 05 e8 9c 48 23 fa 48 83 c4 68 5b 41 5c 41 5d 41 5e 41 5f
>> 5d c3 e8 88 48 23 fa 0f 0b e9 34 ff ff ff e8 7c 48 23 fa <0f> 0b e9 28 ff
>> ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c c1 f9 ff
>> RSP: 0018:ffff8880a9abfc48 EFLAGS: 00010293
>> RAX: ffffffff874fe8a4 RBX: ffff888094160870 RCX: ffff8880a9ab2080
>> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
>> RBP: ffff8880a9abfcd8 R08: ffffffff874fe28e R09: ffffed10123e6969
>> R10: ffffed10123e6969 R11: 0000000000000000 R12: ffff888091f34000
>> R13: dffffc0000000000 R14: ffff8880a80c5000 R15: ffff8880a4481400
>> process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269
>> worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
>> kthread+0x332/0x350 kernel/kthread.c:255
>> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>> Kernel Offset: disabled
>> Rebooting in 86400 seconds..
>>
>>
>> ---
>> This bug is generated by a bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for more information about syzbot.
>> syzbot engineers can be reached at syzk...@googlegroups.com.
>>
>> syzbot will keep track of this bug report. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>> syzbot can test patches for this bug, for details see:
>> https://goo.gl/tpsmEJ#testing-patches
>
>
> For this bug, syzbot does not seem to be able to build the kernel anymore.
> Can bugs like these be considered and closed as invalid?
>
> Thanks,
> Anant

Hi Anant,

+syzkaler, lkml (nobody is generally reading syzkaller-bugs).

What do you mean by "not able to build a kernel for this bug"?
Building a kernel is not related to a particular bug. It's the same
for all bugs...

Re: WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[syzbot]

syzbot has bisected this bug to:

commit 26d051e301f67cdd2ea3404abb43902f13214efa
Author: Arvind Yadav <arvind.yadav.cs@gmail.com>
Date:   Thu Jun 29 08:21:35 2017 +0000

     media: exynos4-is: fimc-is-i2c: constify dev_pm_ops structures

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10a0aff0e00000
start commit:   da940012 Merge tag 'char-misc-5.4-rc3' of git://git.kernel..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12a0aff0e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=14a0aff0e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2d2fd92a28d3e50
dashboard link: https://syzkaller.appspot.com/bug?extid=c0b807de416427ff3dd1
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=141ffd77600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11edd580e00000

Reported-by: syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com
Fixes: 26d051e301f6 ("media: exynos4-is: fimc-is-i2c: constify dev_pm_ops  
structures")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[syzbot]

syzbot has bisected this bug to:

commit 26d051e301f67cdd2ea3404abb43902f13214efa
Author: Arvind Yadav <arvind.yadav.cs@gmail.com>
Date:   Thu Jun 29 08:21:35 2017 +0000

     media: exynos4-is: fimc-is-i2c: constify dev_pm_ops structures

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10a0aff0e00000
start commit:   da940012 Merge tag 'char-misc-5.4-rc3' of git://git.kernel..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12a0aff0e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=14a0aff0e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2d2fd92a28d3e50
dashboard link: https://syzkaller.appspot.com/bug?extid=c0b807de416427ff3dd1
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=141ffd77600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11edd580e00000

Reported-by: syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com
Fixes: 26d051e301f6 ("media: exynos4-is: fimc-is-i2c: constify dev_pm_ops  
structures")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING in batadv_iv_send_outstanding_bat_ogm_packet

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    da940012 Merge tag 'char-misc-5.4-rc3' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ffd808e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2d2fd92a28d3e50
dashboard link: https://syzkaller.appspot.com/bug?extid=c0b807de416427ff3dd1
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=141ffd77600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11edd580e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382  
batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
WARNING: CPU: 1 PID: 30 at net/batman-adv/bat_iv_ogm.c:382  
batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770  
net/batman-adv/bat_iv_ogm.c:1663
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 30 Comm: kworker/u4:2 Not tainted 5.4.0-rc2+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
  panic+0x264/0x7a9 kernel/panic.c:221
  __warn+0x20e/0x210 kernel/panic.c:582
  report_bug+0x1b6/0x2f0 lib/bug.c:195
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
  do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
  invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:382 [inline]
RIP: 0010:batadv_iv_send_outstanding_bat_ogm_packet+0x6b4/0x770  
net/batman-adv/bat_iv_ogm.c:1663
Code: 66 05 00 eb 05 e8 9c 48 23 fa 48 83 c4 68 5b 41 5c 41 5d 41 5e 41 5f  
5d c3 e8 88 48 23 fa 0f 0b e9 34 ff ff ff e8 7c 48 23 fa <0f> 0b e9 28 ff  
ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c c1 f9 ff
RSP: 0018:ffff8880a9abfc48 EFLAGS: 00010293
RAX: ffffffff874fe8a4 RBX: ffff888094160870 RCX: ffff8880a9ab2080
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffff8880a9abfcd8 R08: ffffffff874fe28e R09: ffffed10123e6969
R10: ffffed10123e6969 R11: 0000000000000000 R12: ffff888091f34000
R13: dffffc0000000000 R14: ffff8880a80c5000 R15: ffff8880a4481400
  process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269
  worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
  kthread+0x332/0x350 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches