linux-kernel - Re: [syzbot] [f2fs?] INFO: task hung in do

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Message-ID: <68089b8d.050a0220.36a438.000a.GAE@google.com>
Date: Wed, 23 Apr 2025 00:49:33 -0700
From: syzbot <syzbot+effe7da6578cd423f98f@...kaller.appspotmail.com>
To: brauner@...nel.org, chao@...nel.org, jack@...e.cz, jaegeuk@...nel.org, 
	kent.overstreet@...ux.dev, linux-bcachefs@...r.kernel.org, 
	linux-f2fs-devel@...ts.sourceforge.net, linux-fsdevel@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com, 
	viro@...iv.linux.org.uk
Subject: Re: [syzbot] [f2fs?] INFO: task hung in do_truncate (3)

syzbot has found a reproducer for the following issue on:

HEAD commit:    bc3372351d0c Merge tag 'for-6.15-rc3-tag' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=138cdccc580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3bbffc3b5b4301e1
dashboard link: https://syzkaller.appspot.com/bug?extid=effe7da6578cd423f98f
compiler:       Debian clang version 15.0.6, Debian LLD 15.0.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17c8ac70580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6c893a6bd7cc/disk-bc337235.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6c31d81cbcae/vmlinux-bc337235.xz
kernel image: https://storage.googleapis.com/syzbot-assets/acf5d144656b/bzImage-bc337235.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/53b1b110f131/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=16d4f204580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/3185ba5a394f/mount_4.gz
  fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14ebe7ac580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+effe7da6578cd423f98f@...kaller.appspotmail.com

INFO: task syz.9.68:6713 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.68        state:D stack:27592 pid:6713  tgid:6701  ppid:6519   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 rwsem_down_write_slowpath+0xedd/0x1420 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1da/0x220 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:867 [inline]
 do_truncate+0x20e/0x310 fs/open.c:63
 vfs_truncate+0x4a6/0x540 fs/open.c:115
 do_sys_truncate+0xd8/0x190 fs/open.c:138
 __do_sys_truncate fs/open.c:150 [inline]
 __se_sys_truncate fs/open.c:148 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:148
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6c9918e169
RSP: 002b:00007f6c983dd038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f6c993b6080 RCX: 00007f6c9918e169
RDX: 0000000000000000 RSI: 0000000000008001 RDI: 00002000000000c0
RBP: 00007f6c99210a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f6c993b6080 R15: 00007ffc2675ba78


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.