kernel panic: stack is corrupted in vhost_net_ioctl

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    6c9594bd Merge branch 'for-linus' of git://git.kernel.org/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17059c6ae00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7654f9089a2e8c85
dashboard link: https://syzkaller.appspot.com/bug?extid=f2a62d07a5198c819c7b
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17bacb3ae00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f2a62d07a5198c819c7b@xxxxxxxxxxxxxxxxxxxxxxxxx

Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:  
vhost_net_ioctl+0x1d8c/0x1dc0 drivers/vhost/net.c:366
CPU: 1 PID: 7993 Comm: syz-executor.0 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 panic+0x264/0x7a9 kernel/panic.c:221
 __stack_chk_fail+0x1f/0x20 kernel/panic.c:667
 vhost_net_ioctl+0x1d8c/0x1dc0 drivers/vhost/net.c:366
 do_vfs_ioctl+0x744/0x1730 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a639
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f473d635c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639
RDX: 0000000020d7c000 RSI: 000000004008af30 RDI: 0000000000000003
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f473d6366d4
R13: 00000000004c5b18 R14: 00000000004dab78 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..


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