[syzbot] [block?] WARNING in user_reset_fdc
From: syzbot
Date: Fri Aug 18 2023 - 12:16:06 EST
Hello,
syzbot found the following issue on:
HEAD commit: 16931859a650 Merge tag 'nfsd-6.5-4' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10f58a4ba80000
kernel config: https://syzkaller.appspot.com/x/.config?x=aa796b6080b04102
dashboard link: https://syzkaller.appspot.com/bug?extid=233dd451466273c18ef0
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-16931859.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bdf15da7f883/vmlinux-16931859.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3793fa211ca9/bzImage-16931859.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+233dd451466273c18ef0@xxxxxxxxxxxxxxxxxxxxxxxxx
------------[ cut here ]------------
WARNING: CPU: 2 PID: 26006 at drivers/block/floppy.c:999 schedule_bh drivers/block/floppy.c:999 [inline]
WARNING: CPU: 2 PID: 26006 at drivers/block/floppy.c:999 process_fd_request drivers/block/floppy.c:2847 [inline]
WARNING: CPU: 2 PID: 26006 at drivers/block/floppy.c:999 user_reset_fdc+0x1a1/0x1e0 drivers/block/floppy.c:2945
Modules linked in:
CPU: 2 PID: 26006 Comm: syz-executor.3 Not tainted 6.5.0-rc6-syzkaller-00038-g16931859a650 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:schedule_bh drivers/block/floppy.c:999 [inline]
RIP: 0010:process_fd_request drivers/block/floppy.c:2847 [inline]
RIP: 0010:user_reset_fdc+0x1a1/0x1e0 drivers/block/floppy.c:2945
Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 02 7e 27 48 8d 04 9b 80 0c c5 38 37 42 92 04 e9 b4 fe ff ff e8 bf e8 4f fc <0f> 0b e9 3d ff ff ff e8 93 f5 a3 fc e9 d8 fe ff ff e8 29 f6 a3 fc
RSP: 0018:ffffc900283af978 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88801ccec800 RSI: ffffffff85361fe1 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000001 R14: 0000000000000012 R15: 0000000000000012
FS: 0000000000000000(0000) GS:ffff88802c800000(0063) knlGS:00000000f7fb4b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f731c268 CR3: 0000000069b30000 CR4: 0000000000350ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
fd_locked_ioctl+0xa78/0x1a10 drivers/block/floppy.c:3542
fd_ioctl drivers/block/floppy.c:3576 [inline]
fd_compat_ioctl+0x90b/0x1d00 drivers/block/floppy.c:3890
compat_blkdev_ioctl+0x2fe/0x7c0 block/ioctl.c:677
__do_compat_sys_ioctl+0x2bf/0x330 fs/ioctl.c:968
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x70/0x82
RIP: 0023:0xf7fb9579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f7fb45ac EFLAGS: 00000292 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000254
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
---
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