Re: [syzbot] kernel BUG in vhost_get_vq_desc

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in vhost_get_vq_desc

------------[ cut here ]------------
kernel BUG at drivers/vhost/vhost.c:2337!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4061 Comm: vhost-4060 Not tainted 5.17.0-rc4-syzkaller-00054-gf71077a4d84b-dirty #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:2337
Code: 00 00 00 48 c7 c6 20 2c 9d 8a 48 c7 c7 98 a6 8e 8d 48 89 ca 48 c1 e1 04 48 01 d9 e8 57 59 28 fd e9 74 ff ff ff e8 fd c7 a1 fa <0f> 0b e8 f6 c7 a1 fa 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffffc9000204fb88 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff888077138000 RSI: ffffffff86d71623 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff86d7071c R11: 0000000000000000 R12: ffff888079664d68
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888079664bb0
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcc525c41d0 CR3: 000000001816c000 CR4: 00000000003506f0
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:2337
Code: 00 00 00 48 c7 c6 20 2c 9d 8a 48 c7 c7 98 a6 8e 8d 48 89 ca 48 c1 e1 04 48 01 d9 e8 57 59 28 fd e9 74 ff ff ff e8 fd c7 a1 fa <0f> 0b e8 f6 c7 a1 fa 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffffc9000204fb88 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff888077138000 RSI: ffffffff86d71623 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff86d7071c R11: 0000000000000000 R12: ffff888079664d68
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888079664bb0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 000000001816c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         f71077a4 Merge tag 'mmc-v5.17-rc1-2' of git://git.kern..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
console output: https://syzkaller.appspot.com/x/log.txt?x=128be8ea700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a78b064590b9f912
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
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1651c3d2700000