Subject: [syzbot] kernel BUG in vhost_get_vq_desc

From: syzbot <[email-masked]>
Date: Sat, 12 Feb 2022 14:47:22 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    83e396641110 Merge tag 'soc-fixes-5.17-1' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1282df74700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5707221760c00a20
dashboard link: https://syzkaller.appspot.com/bug?extid=3140b17cb44a7b174008
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
kernel BUG at drivers/vhost/vhost.c:2335!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 9449 Comm: vhost-9447 Not tainted 5.17.0-rc3-syzkaller-00247-g83e396641110 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:vhost_get_vq_desc+0x1d43/0x22c0 drivers/vhost/vhost.c:2335
Code: 00 00 00 48 c7 c6 00 ac 9c 8a 48 c7 c7 28 27 8e 8d 48 89 ca 48 c1 e1 04 48 01 d9 e8 77 23 29 fd e9 74 ff ff ff e8 bd 3f a3 fa <0f> 0b e8 b6 3f a3 fa 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffffc9000f527b88 EFLAGS: 00010212

RAX: 0000000000000133 RBX: 0000000000000001 RCX: ffffc9000ef65000
RDX: 0000000000040000 RSI: ffffffff86d46e33 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff86d45f2c R11: 0000000000000000 R12: ffff88802bac4d68
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88802bac4bb0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6c74f8a718 CR3: 000000002bb11000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 vhost_vsock_handle_tx_kick+0x277/0xa20 drivers/vhost/vsock.c:522
 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:vhost_get_vq_desc+0x1d43/0x22c0 drivers/vhost/vhost.c:2335
Code: 00 00 00 48 c7 c6 00 ac 9c 8a 48 c7 c7 28 27 8e 8d 48 89 ca 48 c1 e1 04 48 01 d9 e8 77 23 29 fd e9 74 ff ff ff e8 bd 3f a3 fa <0f> 0b e8 b6 3f a3 fa 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffffc9000f527b88 EFLAGS: 00010212

RAX: 0000000000000133 RBX: 0000000000000001 RCX: ffffc9000ef65000
RDX: 0000000000040000 RSI: ffffffff86d46e33 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff86d45f2c R11: 0000000000000000 R12: ffff88802bac4d68
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88802bac4bb0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6c7679a1b8 CR3: 000000002bb11000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

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