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: 319d, last: 81d
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 197 2d13h 326d 0/28 upstream: reported C repro on 2024/05/06 01:51
linux-6.1 INFO: task hung in do_renameat2 1 423d 423d 0/3 auto-obsoleted due to no activity on 2024/05/09 03:01
upstream INFO: task hung in do_renameat2 f2fs 2 570d 604d 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 318d 318d 0/3 auto-obsoleted due to no activity on 2024/08/22 17:29
Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/03/18 07:23 17m retest repro linux-5.15.y OK log
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.3.193:5303 blocked for more than 143 seconds.
      Not tainted 5.15.173-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.193       state:D stack:28512 pid: 5303 ppid:  4181 flags:0x00004004
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_rename fs/namei.c:5031 [inline]
 __se_sys_rename fs/namei.c:5029 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5029
 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: 0033:0x7ff114589849
RSP: 002b:00007ff1123de058 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007ff11474f080 RCX: 00007ff114589849
RDX: 0000000000000000 RSI: 0000000020000f40 RDI: 00000000200003c0
RBP: 00007ff1145fc986 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007ff11474f080 R15: 00007ffc2de2daf8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3934:
 #0: ffff88802c96c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025c62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz.3.193/5302:
2 locks held by syz.3.193/5303:
 #0: ffff88807cafe460 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff888074fd4188 (&type->i_mutex_dir_key#17/1){+.+.}-{3:3}, at: do_renameat2+0x67e/0x1700 fs/namei.c:4924
1 lock held by syz-executor/6989:
 #0: ffffffff8cb24228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8cb24228 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
2 locks held by dhcpcd-run-hook/7975:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.173-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: 7976 Comm: dhcpcd-run-hook Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:227 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x30/0x80 kernel/kcov.c:300
Code: 8b 0d 34 f8 81 7e 65 8b 05 35 f8 81 7e 25 00 01 ff 00 74 10 3d 00 01 00 00 75 57 83 b9 34 16 00 00 00 74 4e 8b 81 10 16 00 00 <83> f8 03 75 43 48 8b 91 18 16 00 00 44 8b 89 14 16 00 00 49 c1 e1
RSP: 0000:ffffc90003477a10 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880680dd940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffea00002a6340 R08: ffffffff81a830d1 R09: fffff94000054c71
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200068ef6e
R13: ffffc90003477b72 R14: dffffc0000000000 R15: ffffc90003477b60
FS:  00007fe1281d2380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe128287100 CR3: 000000007ca26000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 xa_is_internal include/linux/xarray.h:169 [inline]
 xas_next_entry+0x221/0x3d0 include/linux/xarray.h:1642
 next_map_page mm/filemap.c:3296 [inline]
 filemap_map_pages+0xf90/0x15c0 mm/filemap.c:3352
 do_fault_around mm/memory.c:4241 [inline]
 do_read_fault mm/memory.c:4256 [inline]
 do_fault mm/memory.c:4390 [inline]
 handle_pte_fault mm/memory.c:4648 [inline]
 __handle_mm_fault mm/memory.c:4783 [inline]
 handle_mm_fault+0x341b/0x5960 mm/memory.c:4881
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fe128287100
Code: 68 28 00 00 00 e9 20 ff ff ff ff 25 7a 9b 17 00 68 03 00 00 00 e9 10 ff ff ff ff 25 72 9b 17 00 68 27 00 00 00 e9 00 ff ff ff <ff> 25 6a 9b 17 00 68 26 00 00 00 e9 f0 fe ff ff ff 25 62 9b 17 00
RSP: 002b:00007ffc72350aa8 EFLAGS: 00010202
RAX: 0000556b526f3e58 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000cfa RSI: 00007fe1283c52ea RDI: 0000556b526f3e58
RBP: 0000556b526f3e58 R08: 0000556b526e3c60 R09: 00007fe128401b20
R10: 0000000000000011 R11: 0000000000000000 R12: 0000556b526e3c60
R13: 0000556b526ea5c0 R14: 0000556b526e2910 R15: 0000000000000000
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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 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
2024/10/27 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.