Hello,
syzbot found the following issue on:
HEAD commit: 048c796beb6e ipv6: adjust ndisc_is_useropt() to also retur..
git tree: net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=103213a5a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa5bd4cd5ab6259d
dashboard link: https://syzkaller.appspot.com/bug?extid=d810d3cd45ed1848c3f7
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1475a873a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153cc91ba80000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bf6b84b5998f/disk-048c796b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4000dee89ebe/vmlinux-048c796b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b700ee9bd306/bzImage-048c796b.xz
The issue was bisected to:
commit 718cb09aaa6fa78cc8124e9517efbc6c92665384
Author: Vlad Buslov <[email protected]>
Date: Tue Aug 8 09:35:21 2023 +0000
vlan: Fix VLAN 0 memory leak
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12cbf169a80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11cbf169a80000
console output: https://syzkaller.appspot.com/x/log.txt?x=16cbf169a80000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
Fixes: 718cb09aaa6f ("vlan: Fix VLAN 0 memory leak")
------------[ cut here ]------------
WARNING: CPU: 0 PID: 12 at net/core/dev.c:10876 unregister_netdevice_many_notify+0x14d8/0x19a0 net/core/dev.c:10876
Modules linked in:
CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.5.0-rc4-syzkaller-00248-g048c796beb6e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Workqueue: netns cleanup_net
RIP: 0010:unregister_netdevice_many_notify+0x14d8/0x19a0 net/core/dev.c:10876
Code: b4 1a 00 00 48 c7 c6 e0 18 81 8b 48 c7 c7 20 19 81 8b c6 05 ab 19 6c 06 01 e8 b4 22 23 f9 0f 0b e9 64 f7 ff ff e8 68 60 5c f9 <0f> 0b e9 3b f7 ff ff e8 fc 68 b0 f9 e9 fc ec ff ff 4c 89 e7 e8 4f
RSP: 0018:ffffc90000117a30 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000070de5201 RCX: 0000000000000000
RDX: ffff88801526d940 RSI: ffffffff8829a7b8 RDI: 0000000000000001
RBP: ffff88807d7ee000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff81004e11 R12: ffff888018fb2a00
R13: 0000000000000000 R14: 0000000000000002 R15: ffff888018fb2a00
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005581d741a950 CR3: 000000007deef000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ip6_tnl_exit_batch_net+0x57d/0x6f0 net/ipv6/ip6_tunnel.c:2278
ops_exit_list+0x125/0x170 net/core/net_namespace.c:175
cleanup_net+0x505/0xb20 net/core/net_namespace.c:614
process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
worker_thread+0x687/0x1110 kernel/workqueue.c:2748
kthread+0x33a/0x430 kernel/kthread.c:389
ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
</TASK>
---
This report 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 [email protected].
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
On Fri, Aug 11, 2023 at 06:57:07AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 048c796beb6e ipv6: adjust ndisc_is_useropt() to also retur..
> git tree: net
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=103213a5a80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=fa5bd4cd5ab6259d
> dashboard link: https://syzkaller.appspot.com/bug?extid=d810d3cd45ed1848c3f7
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1475a873a80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153cc91ba80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/bf6b84b5998f/disk-048c796b.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/4000dee89ebe/vmlinux-048c796b.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/b700ee9bd306/bzImage-048c796b.xz
>
> The issue was bisected to:
>
> commit 718cb09aaa6fa78cc8124e9517efbc6c92665384
> Author: Vlad Buslov <[email protected]>
> Date: Tue Aug 8 09:35:21 2023 +0000
>
> vlan: Fix VLAN 0 memory leak
I wasn't able to reproduce using the C reproducer, but I'm pretty sure I
know what is the problem. I wasn't aware that user space can create VLAN
devices with VID 0, which can result in the VLAN driver wrongly deleting
it upon NETDEV_DOWN. Reproduced using:
ip link add name dummy1 up type dummy
ip link add link dummy1 name dummy1.0 type vlan id 0
ip link del dev dummy1
Always adding VID 0 on NETDEV_UP "solves" the problem, but it will
increase the memory consumption for each netdev, which is not ideal. A
possible solution is trying to delete VID 0 upon NETDEV_UNREGISTER
instead of only iterating over upper VLAN devices.
Anyway, Vlad, it's probably best to send a revert while we figure it
out.
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12cbf169a80000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=11cbf169a80000
> console output: https://syzkaller.appspot.com/x/log.txt?x=16cbf169a80000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
> Fixes: 718cb09aaa6f ("vlan: Fix VLAN 0 memory leak")
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 12 at net/core/dev.c:10876 unregister_netdevice_many_notify+0x14d8/0x19a0 net/core/dev.c:10876
> Modules linked in:
> CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.5.0-rc4-syzkaller-00248-g048c796beb6e #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
> Workqueue: netns cleanup_net
> RIP: 0010:unregister_netdevice_many_notify+0x14d8/0x19a0 net/core/dev.c:10876
> Code: b4 1a 00 00 48 c7 c6 e0 18 81 8b 48 c7 c7 20 19 81 8b c6 05 ab 19 6c 06 01 e8 b4 22 23 f9 0f 0b e9 64 f7 ff ff e8 68 60 5c f9 <0f> 0b e9 3b f7 ff ff e8 fc 68 b0 f9 e9 fc ec ff ff 4c 89 e7 e8 4f
> RSP: 0018:ffffc90000117a30 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: 0000000070de5201 RCX: 0000000000000000
> RDX: ffff88801526d940 RSI: ffffffff8829a7b8 RDI: 0000000000000001
> RBP: ffff88807d7ee000 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000001 R11: ffffffff81004e11 R12: ffff888018fb2a00
> R13: 0000000000000000 R14: 0000000000000002 R15: ffff888018fb2a00
> FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00005581d741a950 CR3: 000000007deef000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> ip6_tnl_exit_batch_net+0x57d/0x6f0 net/ipv6/ip6_tunnel.c:2278
> ops_exit_list+0x125/0x170 net/core/net_namespace.c:175
> cleanup_net+0x505/0xb20 net/core/net_namespace.c:614
> process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
> worker_thread+0x687/0x1110 kernel/workqueue.c:2748
> kthread+0x33a/0x430 kernel/kthread.c:389
> ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> </TASK>
>
>
> ---
> This report 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 [email protected].
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>
On Fri 11 Aug 2023 at 18:03, Ido Schimmel <[email protected]> wrote:
> On Fri, Aug 11, 2023 at 06:57:07AM -0700, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 048c796beb6e ipv6: adjust ndisc_is_useropt() to also retur..
>> git tree: net
>> console+strace: https://syzkaller.appspot.com/x/log.txt?x=103213a5a80000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=fa5bd4cd5ab6259d
>> dashboard link: https://syzkaller.appspot.com/bug?extid=d810d3cd45ed1848c3f7
>> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1475a873a80000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153cc91ba80000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/bf6b84b5998f/disk-048c796b.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/4000dee89ebe/vmlinux-048c796b.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/b700ee9bd306/bzImage-048c796b.xz
>>
>> The issue was bisected to:
>>
>> commit 718cb09aaa6fa78cc8124e9517efbc6c92665384
>> Author: Vlad Buslov <[email protected]>
>> Date: Tue Aug 8 09:35:21 2023 +0000
>>
>> vlan: Fix VLAN 0 memory leak
>
> I wasn't able to reproduce using the C reproducer, but I'm pretty sure I
> know what is the problem. I wasn't aware that user space can create VLAN
> devices with VID 0, which can result in the VLAN driver wrongly deleting
> it upon NETDEV_DOWN. Reproduced using:
>
> ip link add name dummy1 up type dummy
> ip link add link dummy1 name dummy1.0 type vlan id 0
> ip link del dev dummy1
>
> Always adding VID 0 on NETDEV_UP "solves" the problem, but it will
> increase the memory consumption for each netdev, which is not ideal. A
> possible solution is trying to delete VID 0 upon NETDEV_UNREGISTER
> instead of only iterating over upper VLAN devices.
>
> Anyway, Vlad, it's probably best to send a revert while we figure it
> out.
Will do.
>
>>
>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12cbf169a80000
>> final oops: https://syzkaller.appspot.com/x/report.txt?x=11cbf169a80000
>> console output: https://syzkaller.appspot.com/x/log.txt?x=16cbf169a80000
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: [email protected]
>> Fixes: 718cb09aaa6f ("vlan: Fix VLAN 0 memory leak")
>>
>> ------------[ cut here ]------------
>> WARNING: CPU: 0 PID: 12 at net/core/dev.c:10876 unregister_netdevice_many_notify+0x14d8/0x19a0 net/core/dev.c:10876
>> Modules linked in:
>> CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.5.0-rc4-syzkaller-00248-g048c796beb6e #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
>> Workqueue: netns cleanup_net
>> RIP: 0010:unregister_netdevice_many_notify+0x14d8/0x19a0 net/core/dev.c:10876
>> Code: b4 1a 00 00 48 c7 c6 e0 18 81 8b 48 c7 c7 20 19 81 8b c6 05 ab 19 6c 06 01 e8 b4 22 23 f9 0f 0b e9 64 f7 ff ff e8 68 60 5c f9 <0f> 0b e9 3b f7 ff ff e8 fc 68 b0 f9 e9 fc ec ff ff 4c 89 e7 e8 4f
>> RSP: 0018:ffffc90000117a30 EFLAGS: 00010293
>> RAX: 0000000000000000 RBX: 0000000070de5201 RCX: 0000000000000000
>> RDX: ffff88801526d940 RSI: ffffffff8829a7b8 RDI: 0000000000000001
>> RBP: ffff88807d7ee000 R08: 0000000000000001 R09: 0000000000000000
>> R10: 0000000000000001 R11: ffffffff81004e11 R12: ffff888018fb2a00
>> R13: 0000000000000000 R14: 0000000000000002 R15: ffff888018fb2a00
>> FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00005581d741a950 CR3: 000000007deef000 CR4: 00000000003506f0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> Call Trace:
>> <TASK>
>> ip6_tnl_exit_batch_net+0x57d/0x6f0 net/ipv6/ip6_tunnel.c:2278
>> ops_exit_list+0x125/0x170 net/core/net_namespace.c:175
>> cleanup_net+0x505/0xb20 net/core/net_namespace.c:614
>> process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
>> worker_thread+0x687/0x1110 kernel/workqueue.c:2748
>> kthread+0x33a/0x430 kernel/kthread.c:389
>> ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
>> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> </TASK>
>>
>>
>> ---
>> This report 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 [email protected].
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>>
>> If the bug is already fixed, let syzbot know by replying with:
>> #syz fix: exact-commit-title
>>
>> If you want syzbot to run the reproducer, reply with:
>> #syz test: git://repo/address.git branch-or-commit-hash
>> If you attach or paste a git patch, syzbot will apply it before testing.
>>
>> If you want to change bug's subsystems, reply with:
>> #syz set subsystems: new-subsystem
>> (See the list of subsystem names on the web dashboard)
>>
>> If the bug is a duplicate of another bug, reply with:
>> #syz dup: exact-subject-of-another-report
>>
>> If you want to undo deduplication, reply with:
>> #syz undup
>>
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: [email protected]
Tested on:
commit: 048c796b ipv6: adjust ndisc_is_useropt() to also retur..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=10a16cada80000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa5bd4cd5ab6259d
dashboard link: https://syzkaller.appspot.com/bug?extid=d810d3cd45ed1848c3f7
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=1664153ba80000
Note: testing is done by a robot and is best-effort only.