WARNING in hsr_forward_skb

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 195303136f19 Merge tag 'kconfig-v4.21-2' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10abf757400000
kernel config: https://syzkaller.appspot.com/x/.config?x=5e7dc790609552d7
dashboard link: https://syzkaller.appspot.com/bug?extid=fdce8f2a8903f3ba0e6b
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f6d1fd400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17290fdd400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+fdce8f...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
------------[ cut here ]------------
HSR: VLAN not yet supported
WARNING: CPU: 0 PID: 8203 at net/hsr/hsr_forward.c:336 hsr_fill_frame_info
net/hsr/hsr_forward.c:336 [inline]
WARNING: CPU: 0 PID: 8203 at net/hsr/hsr_forward.c:336
hsr_forward_skb+0x2196/0x28a0 net/hsr/hsr_forward.c:370
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8203 Comm: syz-executor112 Not tainted 4.20.0+ #175
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113
panic+0x2ad/0x55f kernel/panic.c:189
__warn.cold.8+0x20/0x52 kernel/panic.c:544
report_bug+0x254/0x2d0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:hsr_fill_frame_info net/hsr/hsr_forward.c:336 [inline]
RIP: 0010:hsr_forward_skb+0x2196/0x28a0 net/hsr/hsr_forward.c:370
Code: e7 e8 9e 2a ff ff e9 8f f3 ff ff 48 89 85 b0 fe ff ff e8 8d d5 95 f9
48 c7 c7 a0 0e fa 88 c6 05 25 bc 4a 02 01 e8 0a 1b 5f f9 <0f> 0b 48 8b 85
a8 fe ff ff 48 b9 00 00 00 00 00 fc ff df 48 89 c2
RSP: 0018:ffff8880a6ae6b28 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88808486b580 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81683f55 RDI: 0000000000000006
RBP: ffff8880a6ae6cb8 R08: ffff8880a8b28100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88808e274400 R14: ffff88808486b636 R15: ffff8880a6ae6c90
hsr_dev_xmit+0x71/0xa0 net/hsr/hsr_device.c:243
__netdev_start_xmit include/linux/netdevice.h:4382 [inline]
netdev_start_xmit include/linux/netdevice.h:4391 [inline]
xmit_one net/core/dev.c:3278 [inline]
dev_hard_start_xmit+0x286/0xc80 net/core/dev.c:3294
__dev_queue_xmit+0x2f62/0x3ac0 net/core/dev.c:3864
dev_queue_xmit+0x17/0x20 net/core/dev.c:3897
packet_snd net/packet/af_packet.c:2932 [inline]
packet_sendmsg+0x298a/0x6ad0 net/packet/af_packet.c:2957
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:631
___sys_sendmsg+0x51d/0x930 net/socket.c:2116
__sys_sendmmsg+0x246/0x6d0 net/socket.c:2211
__do_sys_sendmmsg net/socket.c:2240 [inline]
__se_sys_sendmmsg net/socket.c:2237 [inline]
__x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4418a9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 bb 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdeaf8c9e8 EFLAGS: 00000213 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00000000004418a9
RDX: 0000000000000300 RSI: 0000000020008a80 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000001bbbbbb R09: 0000000001bbbbbb
R10: 0000000000000000 R11: 0000000000000213 R12: 00007ffdeaf8ca30
R13: 00007ffdeaf8ca20 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
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[syzbot]

syzbot has bisected this bug to:

commit ab42f35d9cb5ac49b5a2a11f940e74f58f207280
Author: Ming Lei <ming...@redhat.com>
Date: Fri May 26 11:53:19 2017 +0000

blk-mq: merge bio into sw queue before plugging

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16e68713200000
start commit: ab42f35d blk-mq: merge bio into sw queue before plugging
git tree: upstream
final crash: https://syzkaller.appspot.com/x/report.txt?x=15e68713200000
console output: https://syzkaller.appspot.com/x/log.txt?x=11e68713200000

kernel config: https://syzkaller.appspot.com/x/.config?x=5e7dc790609552d7
dashboard link: https://syzkaller.appspot.com/bug?extid=fdce8f2a8903f3ba0e6b

userspace arch: amd64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f6d1fd400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17290fdd400000

Reported-by: syzbot+fdce8f...@syzkaller.appspotmail.com
Fixes: ab42f35d ("blk-mq: merge bio into sw queue before plugging")

[Oliver Hartkopp]

Hi all,

I'm not sure why a Kernel 4.12.0-rc2+ is used here, but I do not get any
problems on the my latest 5.0.0-06622-g1fc1cd8399ab tree and I strongly
assume this patch showing up in 4.12-rc6

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit?id=74b7b490886852582d986a33443c2ffa50970169

fixes the problem.

Best regards,
Oliver

[Dmitry Vyukov]

On Tue, Mar 12, 2019 at 1:02 PM Oliver Hartkopp <sock...@hartkopp.net> wrote:
>
> Hi all,
>
> I'm not sure why a Kernel 4.12.0-rc2+ is used here, but I do not get any
> problems on the my latest 5.0.0-06622-g1fc1cd8399ab tree and I strongly
> assume this patch showing up in 4.12-rc6
>
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit?id=74b7b490886852582d986a33443c2ffa50970169
>
> fixes the problem.

Hi Oliver,

You can see how bisection progressed and got to 4.12.0-rc2+ in the
bisection log.

The commit that it come up with looks unrelated.
I've started collecting such cases at:
https://github.com/google/syzkaller/issues/1051
and added for this case:

=====
Bisected to wrong commit.
Root cause: broken kernel boots, bugs that happen on all tests.
Boot is broken for several releases with "WARNING in hsr_forward_skb",
this switches to a bug that happens during every test "INFO: trying to
register non-static key in can_notifier", which then leads to a
completely random commit.
=====

> On 3/12/19 9:57 AM, syzbot wrote:
> > syzbot has bisected this bug to:
> >
> > commit ab42f35d9cb5ac49b5a2a11f940e74f58f207280
> > Author: Ming Lei <ming...@redhat.com>
> > Date: Fri May 26 11:53:19 2017 +0000
> >
> > blk-mq: merge bio into sw queue before plugging
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16e68713200000
> > start commit: ab42f35d blk-mq: merge bio into sw queue before plugging
> > git tree: upstream
> > final crash: https://syzkaller.appspot.com/x/report.txt?x=15e68713200000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=11e68713200000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=5e7dc790609552d7
> > dashboard link:
> > https://syzkaller.appspot.com/bug?extid=fdce8f2a8903f3ba0e6b
> > userspace arch: amd64
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f6d1fd400000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17290fdd400000
> >
> > Reported-by: syzbot+fdce8f...@syzkaller.appspotmail.com
> > Fixes: ab42f35d ("blk-mq: merge bio into sw queue before plugging")
>

> --
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[Dmitry Vyukov]

On Tue, Mar 12, 2019 at 5:09 PM Dmitry Vyukov <dvy...@google.com> wrote:
>
> On Tue, Mar 12, 2019 at 1:02 PM Oliver Hartkopp <sock...@hartkopp.net> wrote:
> >
> > Hi all,
> >
> > I'm not sure why a Kernel 4.12.0-rc2+ is used here, but I do not get any
> > problems on the my latest 5.0.0-06622-g1fc1cd8399ab tree and I strongly
> > assume this patch showing up in 4.12-rc6
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit?id=74b7b490886852582d986a33443c2ffa50970169
> >
> > fixes the problem.
>
>
> Hi Oliver,
>
> You can see how bisection progressed and got to 4.12.0-rc2+ in the
> bisection log.
>
> The commit that it come up with looks unrelated.
> I've started collecting such cases at:
> https://github.com/google/syzkaller/issues/1051
> and added for this case:
>
> =====
> Bisected to wrong commit.
> Root cause: broken kernel boots, bugs that happen on all tests.
> Boot is broken for several releases with "WARNING in hsr_forward_skb",
> this switches to a bug that happens during every test "INFO: trying to
> register non-static key in can_notifier", which then leads to a
> completely random commit.
> =====

Broken boots did not happen here. "WARNING in hsr_forward_skb" is the
crash that we pursued, so it started correctly. But then diverged to
an unrelated "INFO: trying to register non-static key in
can_notifier".

[Oliver Hartkopp]

Hi Dimitry,

On 3/12/19 5:21 PM, Dmitry Vyukov wrote:

>> You can see how bisection progressed and got to 4.12.0-rc2+ in the
>> bisection log.
>>
>> The commit that it come up with looks unrelated.
>> I've started collecting such cases at:
>> https://github.com/google/syzkaller/issues/1051
>> and added for this case:
>>
>> =====
>> Bisected to wrong commit.
>> Root cause: broken kernel boots, bugs that happen on all tests.
>> Boot is broken for several releases with "WARNING in hsr_forward_skb",
>> this switches to a bug that happens during every test "INFO: trying to
>> register non-static key in can_notifier", which then leads to a
>> completely random commit.
>> =====
>
> Broken boots did not happen here. "WARNING in hsr_forward_skb" is the
> crash that we pursued, so it started correctly. But then diverged to
> an unrelated "INFO: trying to register non-static key in
> can_notifier".

Thanks for the clarification! I really appreciate your effort with syzbot!

Best,
Oliver

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 9d6803921a16f4d768dc41a75375629828f4d91e
Author: Kurt Kanzenbach <ku...@linutronix.de>
Date: Tue Apr 6 07:35:09 2021 +0000

net: hsr: Reset MAC header for Tx path

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=119c7fedd00000
start commit: 3af409ca net: enetc: fix destroyed phylink dereference dur..
git tree: net
kernel config: https://syzkaller.appspot.com/x/.config?x=8cb23303ddb9411f
dashboard link: https://syzkaller.appspot.com/bug?extid=fdce8f2a8903f3ba0e6b
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1525467ad00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=114c0b12d00000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: net: hsr: Reset MAC header for Tx path

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

[Dmitry Vyukov]

The patch references this exact warning.