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Date:   Fri, 27 Oct 2023 01:11:24 -0700
Message-ID: <00000000000008b2940608ae3ce9@google.com>
Subject: [syzbot] [net?] KMSAN: uninit-value in virtio_transport_recv_pkt
From:   syzbot <syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com>
To:     davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, pabeni@redhat.com, sgarzare@redhat.com,
        stefanha@redhat.com, syzkaller-bugs@googlegroups.com,
        virtualization@lists.linux-foundation.org
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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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