syzbot


INFO: task hung in do_renameat2

Status: upstream: reported C repro on 2024/05/13 23:09
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+639adcbeb2636be0d940@syzkaller.appspotmail.com
First crash: 277d, last: 39d
Fix commit to backport (bisect log) :
tree: upstream
commit ffe1b94d7464bef15b6585f9e7f8192cd0668327
Author: Eric Sandeen <sandeen@redhat.com>
Date: Fri Jun 28 00:31:51 2024 +0000

  exfat: Convert to new uid/gid option parsing helpers

  
Bug presence (2)
Date Name Commit Repro Result
2024/10/28 linux-5.15.y (ToT) 74cdd62cb470 C [report] INFO: task hung in do_renameat2
2024/10/28 upstream (ToT) 819837584309 C Didn't crash
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_renameat2 (2) jfs C inconclusive 187 6h06m 285d 0/28 upstream: reported C repro on 2024/05/06 01:51
linux-6.1 INFO: task hung in do_renameat2 1 382d 382d 0/3 auto-obsoleted due to no activity on 2024/05/09 03:01
upstream INFO: task hung in do_renameat2 f2fs 2 528d 563d 0/28 auto-obsoleted due to no activity on 2023/12/04 15:30
linux-6.1 INFO: task hung in do_renameat2 (2) 1 276d 276d 0/3 auto-obsoleted due to no activity on 2024/08/22 17:29
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/01/06 19:07 17m retest repro linux-5.15.y report log
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/11/10 15:50 8h37m fix candidate upstream OK (1) job log

Sample crash report:
INFO: task syz-executor133:4181 blocked for more than 143 seconds.
      Not tainted 5.15.169-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor133 state:D stack:27888 pid: 4181 ppid:  4177 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
 do_renameat2+0x67e/0x1700 fs/namei.c:4924
 __do_sys_renameat2 fs/namei.c:5018 [inline]
 __se_sys_renameat2 fs/namei.c:5015 [inline]
 __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5015
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6f150c0809
RSP: 002b:00007f6f1505c218 EFLAGS: 00000246 ORIG_RAX: 000000000000013c
RAX: ffffffffffffffda RBX: 00007f6f151486d8 RCX: 00007f6f150c0809
RDX: 0000000000000004 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007f6f151486d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00007f6f151155e0
R13: 00007f6f1511407e R14: 0030656c69662f2e R15: 00007f6f151140e0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3926:
 #0: ffff88802cc32098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cbe2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz-executor133/4179:
2 locks held by syz-executor133/4181:
 #0: ffff88802b512460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff888070a482b0 (&sb->s_type->i_mutex_key#15/1){+.+.}-{3:3}, at: do_renameat2+0x67e/0x1700 fs/namei.c:4924

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4179 Comm: syz-executor133 Not tainted 5.15.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xea/0x7a0 kernel/locking/lockdep.c:4259
Code: 03 0f b6 04 10 84 c0 0f 85 42 05 00 00 83 3d 0c 1a 24 15 00 0f 85 a8 00 00 00 4c 8d 74 24 40 4c 89 f3 48 c1 eb 03 80 3c 13 00 <74> 12 4c 89 f7 e8 6c b8 67 00 48 ba 00 00 00 00 00 fc ff df 48 c7
RSP: 0018:ffffc90002d37460 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 1ffff920005a6e94 RCX: ffffffff96869f03
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff81e599c4
RBP: ffffc90002d37520 R08: ffffffff8186f260 R09: ffffed100e131c64
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807098e2b8
R13: 0000000000000000 R14: ffffc90002d374a0 R15: 1ffff920005a6e90
FS:  00007f6f1507d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fce456b3580 CR3: 0000000075589000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
 lookup_bh_lru fs/buffer.c:1294 [inline]
 __find_get_block+0x2c4/0x1350 fs/buffer.c:1306
 __getblk_gfp+0x2d/0xaf0 fs/buffer.c:1332
 __bread_gfp+0x2a/0x390 fs/buffer.c:1381
 sb_bread include/linux/buffer_head.h:337 [inline]
 __exfat_ent_get fs/exfat/fatent.c:47 [inline]
 exfat_ent_get+0x149/0x400 fs/exfat/fatent.c:96
 exfat_readdir fs/exfat/dir.c:184 [inline]
 exfat_iterate+0xda2/0x34a0 fs/exfat/dir.c:258
 iterate_dir+0x224/0x570
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6f150c0809
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6f1507d218 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f6f151486c8 RCX: 00007f6f150c0809
RDX: 0000000000001000 RSI: 0000000020000f80 RDI: 0000000000000005
RBP: 00007f6f151486c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6f151155e0
R13: 00007f6f1511407e R14: 0030656c69662f2e R15: 00007f6f151140e0
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.030 msecs

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/27 11:41 linux-5.15.y 74cdd62cb470 65e8686b .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan INFO: task hung in do_renameat2
2024/12/02 04:30 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in do_renameat2
2024/10/27 06:43 linux-5.15.y 74cdd62cb470 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in do_renameat2
2024/07/21 10:22 linux-5.15.y 7c6d66f0266f b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in do_renameat2
2024/07/07 04:27 linux-5.15.y f45bea23c39c 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in do_renameat2
2024/05/13 23:09 linux-5.15.y 284087d4f7d5 9026e142 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in do_renameat2
* Struck through repros no longer work on HEAD.