WARNING in fd_ioctl

[Wei Chen]

Dear Linux Developer,

Recently when using our tool to fuzz kernel, the following crash was triggered:

HEAD commit: 4fe89d07 Linux v6.0
git tree: upstream
compiler: clang 12.0.0
console output:
https://drive.google.com/file/d/1DcfdIOQBRJq3Z3H02xPLef7t8dkcUVKA/view?usp=sharing
Syzlang reproducer:
https://drive.google.com/file/d/1j4HO4sHdM_-nYDX1_PTNgeL_LQd0ReGV/view?usp=sharing
C reproducer: https://drive.google.com/file/d/1xu7ljT0bxJZNwsjw2WjmE4FmzHG796An/view?usp=sharing
kernel config: https://drive.google.com/file/d/1ZHRxVTXHL9mENdAPmQYS1DtgbflZ9XsD/view?usp=sharing

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: Wei Chen <harperchen1110@xxxxxxxxx>

WARNING: CPU: 0 PID: 6439 at drivers/block/floppy.c:999
process_fd_request drivers/block/floppy.c:2847 [inline]
WARNING: CPU: 0 PID: 6439 at drivers/block/floppy.c:999 do_format
drivers/block/floppy.c:2239 [inline]
WARNING: CPU: 0 PID: 6439 at drivers/block/floppy.c:999
fd_locked_ioctl drivers/block/floppy.c:3501 [inline]
WARNING: CPU: 0 PID: 6439 at drivers/block/floppy.c:999
fd_ioctl+0x1f31/0x26f0 drivers/block/floppy.c:3574
Modules linked in:
CPU: 0 PID: 6439 Comm: syz-executor.0 Not tainted 6.0.0 #35
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 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:do_format drivers/block/floppy.c:2239 [inline]
RIP: 0010:fd_locked_ioctl drivers/block/floppy.c:3501 [inline]
RIP: 0010:fd_ioctl+0x1f31/0x26f0 drivers/block/floppy.c:3574
Code: ff e8 d3 88 9e fc 0f 0b e9 75 fd ff ff e8 c7 88 9e fc 0f 0b e9
ef f3 ff ff e8 bb 88 9e fc 0f 0b e9 8e f4 ff ff e8 af 88 9e fc <0f> 0b
e9 51 fd ff ff e8 a3 88 9e fc 0f 0b e9 9b f9 ff ff 89 d9 80
RSP: 0018:ffffc9000d897ca0 EFLAGS: 00010287
RAX: ffffffff84e89071 RBX: 0000000000000001 RCX: 0000000000040000
RDX: ffffc90005519000 RSI: 0000000000000ccb RDI: 0000000000000ccc
RBP: ffffc9000d897e30 R08: ffffffff84e88dbb R09: fffffbfff1adcf55
R10: fffffbfff1adcf55 R11: 0000000000000000 R12: 1ffff92001b12fa4
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f557132d700(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55703a5864 CR3: 000000006384c000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 blkdev_ioctl+0x3a6/0x770 block/ioctl.c:614
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f557028bded
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f557132cc58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f55703abf80 RCX: 00007f557028bded
RDX: 0000000020000280 RSI: 00000000400c0248 RDI: 0000000000000003
RBP: 00007f55702f8ce0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f55703abf80
R13: 00007ffd41709f0f R14: 00007ffd4170a0b0 R15: 00007f557132cdc0
 </TASK>

Best,
Wei