Re: [syzbot] [block?] [trace?] INFO: task hung in blk_trace_startstop

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    591cd656a1bf Linux 7.0-rc7
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129136ba580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6754c86e8d9e4c91
dashboard link: https://syzkaller.appspot.com/bug?extid=774863666ef5b025c9d0
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1268ad4e580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1580b3da580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6382829d7cc5/disk-591cd656.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/17a325d524d5/vmlinux-591cd656.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0a06ea295210/bzImage-591cd656.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+774863666ef5b025c9d0@xxxxxxxxxxxxxxxxxxxxxxxxx

INFO: task syz.2.19:6128 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:27960 pid:6128  tgid:6125  ppid:5955   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
 blk_debugfs_lock_nomemsave block/blk.h:740 [inline]
 blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:903
 blk_trace_ioctl+0x314/0x920 kernel/trace/blktrace.c:949
 blkdev_common_ioctl+0x13a7/0x3250 block/ioctl.c:724
 blkdev_ioctl+0x528/0x740 block/ioctl.c:798
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f6ab9c819
RSP: 002b:00007f7f6baad028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7f6ae16090 RCX: 00007f7f6ab9c819
RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000003
RBP: 00007f7f6ac32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000


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#syz test: git://repo/address.git branch-or-commit-hash
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