Re: [syzbot] [block?] WARNING in wait_til_done (2)

From: syzbot
Date: Sun Jun 25 2023 - 00:59:08 EST


syzbot has found a reproducer for the following issue on:

HEAD commit: a92b7d26c743 Merge tag 'drm-fixes-2023-06-23' of git://ano..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13426150a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=24ce1b2abaee24cc
dashboard link: https://syzkaller.appspot.com/bug?extid=9bc4da690ee5334f5d15
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17e0603b280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=137e080b280000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-a92b7d26.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/86f5fbd54cd3/vmlinux-a92b7d26.xz
kernel image: https://storage.googleapis.com/syzbot-assets/72b4c75c41dd/bzImage-a92b7d26.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9bc4da690ee5334f5d15@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5531 at drivers/block/floppy.c:999 schedule_bh drivers/block/floppy.c:999 [inline]
WARNING: CPU: 0 PID: 5531 at drivers/block/floppy.c:999 wait_til_done+0x350/0x3c0 drivers/block/floppy.c:2018
Modules linked in:
CPU: 0 PID: 5531 Comm: syz-executor276 Not tainted 6.4.0-rc7-syzkaller-00226-ga92b7d26c743 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:schedule_bh drivers/block/floppy.c:999 [inline]
RIP: 0010:wait_til_done+0x350/0x3c0 drivers/block/floppy.c:2018
Code: fc 41 83 fd 01 7e ac e8 3e 49 60 fc 4c 89 e6 48 c7 c7 60 42 46 8d e8 df 0a 3e fc e8 2a 49 60 fc e9 c3 fd ff ff e8 20 49 60 fc <0f> 0b e9 4b fd ff ff e8 64 1f b2 fc e9 0f fe ff ff e8 0a 49 60 fc
RSP: 0018:ffffc900042ef738 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 1ffff9200085dee7 RCX: 0000000000000000
RDX: ffff888023961500 RSI: ffffffff85232220 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff8522dea0 R14: 0000000000000006 R15: 0000000000000003
FS: 00007fbbf86fe700(0000) GS:ffff88806b600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001ceb0000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
floppy_check_events+0x35e/0x680 drivers/block/floppy.c:4098
disk_check_events+0xc2/0x420 block/disk-events.c:193
disk_clear_events block/disk-events.c:248 [inline]
bdev_check_media_change+0x12a/0x350 block/disk-events.c:279
floppy_open+0x873/0xe90 drivers/block/floppy.c:4057
blkdev_get_whole+0x93/0x2c0 block/bdev.c:606
blkdev_get_by_dev.part.0+0x5e2/0xb80 block/bdev.c:756
blkdev_get_by_dev+0x6f/0x90 block/bdev.c:790
blkdev_open+0x140/0x2d0 block/fops.c:493
do_dentry_open+0x6cc/0x13f0 fs/open.c:920
do_open fs/namei.c:3636 [inline]
path_openat+0x1baa/0x2750 fs/namei.c:3791
do_filp_open+0x1ba/0x410 fs/namei.c:3818
do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x143/0x1f0 fs/open.c:1383
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbbf8f12444
Code: 84 00 00 00 00 00 44 89 54 24 0c e8 c6 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 f8 f9 ff ff 8b 44
RSP: 002b:00007fbbf86fdd60 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbbf8f12444
RDX: 0000000000000000 RSI: 00007fbbf86fdde0 RDI: 00000000ffffff9c
RBP: 00007fbbf86fdde0 R08: 0000000000000000 R09: 00007fbbf86fe700
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007ffdc0de869f R14: 00007fbbf86fe300 R15: 0000000000022000
</TASK>


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