[syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d90b0276af8f Merge tag 'hardening-v6.6-rc3' of git://git.k..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=102c8b22680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6f1a4029b69273f3
dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101e58ec680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7adb6680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/83ae10beee39/disk-d90b0276.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c231992300f6/vmlinux-d90b0276.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6377c9c2ea97/bzImage-d90b0276.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
 virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
 vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was stored to memory at:
 virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
 virtio_transport_recv_pkt+0x1ea4/0x2580 net/vmw_vsock/virtio_transport_common.c:1415
 vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was created at:
 slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
 __alloc_skb+0x318/0x740 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1286 [inline]
 virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
 virtio_transport_alloc_skb+0x8b/0x1170 net/vmw_vsock/virtio_transport_common.c:58
 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
 virtio_transport_recv_pkt+0x1531/0x2580 net/vmw_vsock/virtio_transport_common.c:1387
 vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Workqueue: vsock-loopback vsock_loopback_work
=====================================================


---
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Re: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[Stefano Garzarella]

On Fri, Oct 27, 2023 at 01:11:24AM -0700, syzbot wrote:
>Hello,
>
>syzbot found the following issue on:
>
>HEAD commit:    d90b0276af8f Merge tag 'hardening-v6.6-rc3' of git://git.k..
>git tree:       upstream
>console+strace: https://syzkaller.appspot.com/x/log.txt?x=102c8b22680000
>kernel config:  https://syzkaller.appspot.com/x/.config?x=6f1a4029b69273f3
>dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
>compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101e58ec680000
>C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7adb6680000
>
>Downloadable assets:
>disk image: https://storage.googleapis.com/syzbot-assets/83ae10beee39/disk-d90b0276.raw.xz
>vmlinux: https://storage.googleapis.com/syzbot-assets/c231992300f6/vmlinux-d90b0276.xz
>kernel image: https://storage.googleapis.com/syzbot-assets/6377c9c2ea97/bzImage-d90b0276.xz
>
>IMPORTANT: if you fix the issue, please add the following tag to the commit:
>Reported-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
>
>=====================================================
>BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
> virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
> vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> kthread+0x3e8/0x540 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>Uninit was stored to memory at:
> virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
> virtio_transport_recv_pkt+0x1ea4/0x2580 net/vmw_vsock/virtio_transport_common.c:1415
> vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> kthread+0x3e8/0x540 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>Uninit was created at:
> slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
> slab_alloc_node mm/slub.c:3478 [inline]
> kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
> kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
> __alloc_skb+0x318/0x740 net/core/skbuff.c:650
> alloc_skb include/linux/skbuff.h:1286 [inline]
> virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
> virtio_transport_alloc_skb+0x8b/0x1170 net/vmw_vsock/virtio_transport_common.c:58
> virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
> virtio_transport_recv_pkt+0x1531/0x2580 net/vmw_vsock/virtio_transport_common.c:1387
> vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> kthread+0x3e8/0x540 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
>Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
>Workqueue: vsock-loopback vsock_loopback_work
>=====================================================
>

Shigeru Yoshida already posted a patch here:

https://lore.kernel.org/netdev/20231026150154.3536433-1-syoshida@redhat.com/

Re: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[Stefano Garzarella]

On Fri, Oct 27, 2023 at 01:11:24AM -0700, syzbot wrote:
>Hello,
>
>syzbot found the following issue on:
>
>HEAD commit:    d90b0276af8f Merge tag 'hardening-v6.6-rc3' of git://git.k..
>git tree:       upstream
>console+strace: https://syzkaller.appspot.com/x/log.txt?x=102c8b22680000
>kernel config:  https://syzkaller.appspot.com/x/.config?x=6f1a4029b69273f3
>dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
>compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101e58ec680000
>C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7adb6680000
>
>Downloadable assets:
>disk image: https://storage.googleapis.com/syzbot-assets/83ae10beee39/disk-d90b0276.raw.xz
>vmlinux: https://storage.googleapis.com/syzbot-assets/c231992300f6/vmlinux-d90b0276.xz
>kernel image: https://storage.googleapis.com/syzbot-assets/6377c9c2ea97/bzImage-d90b0276.xz
>
>IMPORTANT: if you fix the issue, please add the following tag to the commit:
>Reported-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
>
>=====================================================
>BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
> virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
> vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> kthread+0x3e8/0x540 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>Uninit was stored to memory at:
> virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
> virtio_transport_recv_pkt+0x1ea4/0x2580 net/vmw_vsock/virtio_transport_common.c:1415
> vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> kthread+0x3e8/0x540 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>Uninit was created at:
> slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
> slab_alloc_node mm/slub.c:3478 [inline]
> kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
> kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
> __alloc_skb+0x318/0x740 net/core/skbuff.c:650
> alloc_skb include/linux/skbuff.h:1286 [inline]
> virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
> virtio_transport_alloc_skb+0x8b/0x1170 net/vmw_vsock/virtio_transport_common.c:58
> virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
> virtio_transport_recv_pkt+0x1531/0x2580 net/vmw_vsock/virtio_transport_common.c:1387
> vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> kthread+0x3e8/0x540 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
>Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
>Workqueue: vsock-loopback vsock_loopback_work
>=====================================================
>

Shigeru Yoshida already posted a patch here:

https://lore.kernel.org/netdev/20231026150154.3536433-1-syoshida@redhat.com/

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Re: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[Eric Dumazet]

On Fri, Oct 27, 2023 at 10:25 AM Stefano Garzarella <sgarzare@redhat.com> wrote:
>
> On Fri, Oct 27, 2023 at 01:11:24AM -0700, syzbot wrote:
> >Hello,
> >
> >syzbot found the following issue on:
> >
> >HEAD commit:    d90b0276af8f Merge tag 'hardening-v6.6-rc3' of git://git.k..
> >git tree:       upstream
> >console+strace: https://syzkaller.appspot.com/x/log.txt?x=102c8b22680000
> >kernel config:  https://syzkaller.appspot.com/x/.config?x=6f1a4029b69273f3
> >dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
> >compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> >syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101e58ec680000
> >C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7adb6680000
> >
> >Downloadable assets:
> >disk image: https://storage.googleapis.com/syzbot-assets/83ae10beee39/disk-d90b0276.raw.xz
> >vmlinux: https://storage.googleapis.com/syzbot-assets/c231992300f6/vmlinux-d90b0276.xz
> >kernel image: https://storage.googleapis.com/syzbot-assets/6377c9c2ea97/bzImage-d90b0276.xz
> >
> >IMPORTANT: if you fix the issue, please add the following tag to the commit:
> >Reported-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
> >
> >=====================================================
> >BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
> > virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> > process_one_work kernel/workqueue.c:2630 [inline]
> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> > kthread+0x3e8/0x540 kernel/kthread.c:388
> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> >
> >Uninit was stored to memory at:
> > virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
> > virtio_transport_recv_pkt+0x1ea4/0x2580 net/vmw_vsock/virtio_transport_common.c:1415
> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> > process_one_work kernel/workqueue.c:2630 [inline]
> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> > kthread+0x3e8/0x540 kernel/kthread.c:388
> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> >
> >Uninit was created at:
> > slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
> > slab_alloc_node mm/slub.c:3478 [inline]
> > kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
> > kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
> > __alloc_skb+0x318/0x740 net/core/skbuff.c:650
> > alloc_skb include/linux/skbuff.h:1286 [inline]
> > virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
> > virtio_transport_alloc_skb+0x8b/0x1170 net/vmw_vsock/virtio_transport_common.c:58
> > virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
> > virtio_transport_recv_pkt+0x1531/0x2580 net/vmw_vsock/virtio_transport_common.c:1387
> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
> > process_one_work kernel/workqueue.c:2630 [inline]
> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
> > kthread+0x3e8/0x540 kernel/kthread.c:388
> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> >
> >CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
> >Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
> >Workqueue: vsock-loopback vsock_loopback_work
> >=====================================================
> >
>
> Shigeru Yoshida already posted a patch here:
>
> https://lore.kernel.org/netdev/20231026150154.3536433-1-syoshida@redhat.com/

Sure thing, this is why I released this syzbot report from my queue.

Re: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[Stefano Garzarella]

On Fri, Oct 27, 2023 at 10:48:39AM +0200, Eric Dumazet wrote:
>On Fri, Oct 27, 2023 at 10:25 AM Stefano Garzarella <sgarzare@redhat.com> wrote:
>>
>> On Fri, Oct 27, 2023 at 01:11:24AM -0700, syzbot wrote:
>> >Hello,
>> >
>> >syzbot found the following issue on:
>> >
>> >HEAD commit:    d90b0276af8f Merge tag 'hardening-v6.6-rc3' of git://git.k..
>> >git tree:       upstream
>> >console+strace: https://syzkaller.appspot.com/x/log.txt?x=102c8b22680000
>> >kernel config:  https://syzkaller.appspot.com/x/.config?x=6f1a4029b69273f3
>> >dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
>> >compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>> >syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101e58ec680000
>> >C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7adb6680000
>> >
>> >Downloadable assets:
>> >disk image: https://storage.googleapis.com/syzbot-assets/83ae10beee39/disk-d90b0276.raw.xz
>> >vmlinux: https://storage.googleapis.com/syzbot-assets/c231992300f6/vmlinux-d90b0276.xz
>> >kernel image: https://storage.googleapis.com/syzbot-assets/6377c9c2ea97/bzImage-d90b0276.xz
>> >
>> >IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> >Reported-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
>> >
>> >=====================================================
>> >BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
>> > virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
>> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
>> > process_one_work kernel/workqueue.c:2630 [inline]
>> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
>> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
>> > kthread+0x3e8/0x540 kernel/kthread.c:388
>> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> >
>> >Uninit was stored to memory at:
>> > virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
>> > virtio_transport_recv_pkt+0x1ea4/0x2580 net/vmw_vsock/virtio_transport_common.c:1415
>> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
>> > process_one_work kernel/workqueue.c:2630 [inline]
>> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
>> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
>> > kthread+0x3e8/0x540 kernel/kthread.c:388
>> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> >
>> >Uninit was created at:
>> > slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
>> > slab_alloc_node mm/slub.c:3478 [inline]
>> > kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
>> > kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
>> > __alloc_skb+0x318/0x740 net/core/skbuff.c:650
>> > alloc_skb include/linux/skbuff.h:1286 [inline]
>> > virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
>> > virtio_transport_alloc_skb+0x8b/0x1170 net/vmw_vsock/virtio_transport_common.c:58
>> > virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
>> > virtio_transport_recv_pkt+0x1531/0x2580 net/vmw_vsock/virtio_transport_common.c:1387
>> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
>> > process_one_work kernel/workqueue.c:2630 [inline]
>> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
>> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
>> > kthread+0x3e8/0x540 kernel/kthread.c:388
>> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> >
>> >CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
>> >Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
>> >Workqueue: vsock-loopback vsock_loopback_work
>> >=====================================================
>> >
>>
>> Shigeru Yoshida already posted a patch here:
>>
>> https://lore.kernel.org/netdev/20231026150154.3536433-1-syoshida@redhat.com/
>
>Sure thing, this is why I released this syzbot report from my queue.
>

Thanks for that ;-)

Stefano

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Virtualization@lists.linux-foundation.org
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Re: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[Stefano Garzarella]

On Fri, Oct 27, 2023 at 10:48:39AM +0200, Eric Dumazet wrote:
>On Fri, Oct 27, 2023 at 10:25 AM Stefano Garzarella <sgarzare@redhat.com> wrote:
>>
>> On Fri, Oct 27, 2023 at 01:11:24AM -0700, syzbot wrote:
>> >Hello,
>> >
>> >syzbot found the following issue on:
>> >
>> >HEAD commit:    d90b0276af8f Merge tag 'hardening-v6.6-rc3' of git://git.k..
>> >git tree:       upstream
>> >console+strace: https://syzkaller.appspot.com/x/log.txt?x=102c8b22680000
>> >kernel config:  https://syzkaller.appspot.com/x/.config?x=6f1a4029b69273f3
>> >dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
>> >compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>> >syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101e58ec680000
>> >C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7adb6680000
>> >
>> >Downloadable assets:
>> >disk image: https://storage.googleapis.com/syzbot-assets/83ae10beee39/disk-d90b0276.raw.xz
>> >vmlinux: https://storage.googleapis.com/syzbot-assets/c231992300f6/vmlinux-d90b0276.xz
>> >kernel image: https://storage.googleapis.com/syzbot-assets/6377c9c2ea97/bzImage-d90b0276.xz
>> >
>> >IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> >Reported-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
>> >
>> >=====================================================
>> >BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
>> > virtio_transport_recv_pkt+0x1c42/0x2580 net/vmw_vsock/virtio_transport_common.c:1421
>> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
>> > process_one_work kernel/workqueue.c:2630 [inline]
>> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
>> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
>> > kthread+0x3e8/0x540 kernel/kthread.c:388
>> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> >
>> >Uninit was stored to memory at:
>> > virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
>> > virtio_transport_recv_pkt+0x1ea4/0x2580 net/vmw_vsock/virtio_transport_common.c:1415
>> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
>> > process_one_work kernel/workqueue.c:2630 [inline]
>> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
>> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
>> > kthread+0x3e8/0x540 kernel/kthread.c:388
>> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> >
>> >Uninit was created at:
>> > slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
>> > slab_alloc_node mm/slub.c:3478 [inline]
>> > kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
>> > kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
>> > __alloc_skb+0x318/0x740 net/core/skbuff.c:650
>> > alloc_skb include/linux/skbuff.h:1286 [inline]
>> > virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
>> > virtio_transport_alloc_skb+0x8b/0x1170 net/vmw_vsock/virtio_transport_common.c:58
>> > virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
>> > virtio_transport_recv_pkt+0x1531/0x2580 net/vmw_vsock/virtio_transport_common.c:1387
>> > vsock_loopback_work+0x3e2/0x5d0 net/vmw_vsock/vsock_loopback.c:120
>> > process_one_work kernel/workqueue.c:2630 [inline]
>> > process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
>> > worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
>> > kthread+0x3e8/0x540 kernel/kthread.c:388
>> > ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>> > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>> >
>> >CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.6.0-rc2-syzkaller-00337-gd90b0276af8f #0
>> >Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
>> >Workqueue: vsock-loopback vsock_loopback_work
>> >=====================================================
>> >
>>
>> Shigeru Yoshida already posted a patch here:
>>
>> https://lore.kernel.org/netdev/20231026150154.3536433-1-syoshida@redhat.com/
>
>Sure thing, this is why I released this syzbot report from my queue.
>

Thanks for that ;-)

Stefano

Re: [syzbot] Test for 0c8ce1da0ac31abbadcd

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Test for 0c8ce1da0ac31abbadcd
Author: syoshida@redhat.com

#syz test

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index e22c81435ef7..dc65dd4d26df 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -130,6 +130,8 @@ static void virtio_transport_init_hdr(struct sk_buff *skb,
 	hdr->dst_port	= cpu_to_le32(dst_port);
 	hdr->flags	= cpu_to_le32(info->flags);
 	hdr->len	= cpu_to_le32(payload_len);
+	hdr->buf_alloc	= cpu_to_le32(0);
+	hdr->fwd_cnt	= cpu_to_le32(0);
 }
 
 static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,

Re: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com

Tested on:

commit:         bc3012f4 Merge tag 'v6.7-p1' of git://git.kernel.org/p..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1155ea23680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d70e93d6569aac97
dashboard link: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1431d76b680000

Note: testing is done by a robot and is best-effort only.