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INFO: task hung in nilfs_transaction_begin (3)

Status: upstream: reported C repro on 2026/07/16 07:51
Subsystems: nilfs
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+cae54346a70bbceeff2c@syzkaller.appspotmail.com
First crash: 2d19h, last: 2d14h
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
31b55954-22cb-4c6e-9446-f4b48578c639 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task hung in nilfs_transaction_begin (3) 2026/07/16 00:00 2026/07/16 00:00 2026/07/16 00:55 10d97020b199b1f285ec4bc6c5f7092b5af41892 

			
				
	

	
	



			

		

	

	
	

		

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			Discussions (3)
		

		

			
			
			



	
	

		Title
		Replies (including bot)
		Last reply
	

	
	
	
		

			[PATCH v2] nilfs2: fix infinite loop in nilfs_clean_segments()
			2 (2)
			2026/07/17 13:30
		

	
		

			[PATCH] nilfs2: fix infinite loop in nilfs_clean_segments()
			3 (3)
			2026/07/17 10:40
		

	
		

			[syzbot] [nilfs?] INFO: task hung in nilfs_transaction_begin (3)
			0 (3)
			2026/07/16 22:05
		

	
	




			
			
		

	

	
	

		

			▶
			▼
			Similar bugs (2)
		

		

			




	
	

		
			Kernel
		
		Title
		
			Rank
			
🛈

		
		Repro
		Cause bisect
		Fix bisect
		Count
		Last
		Reported
		
		
		
			Patched
		
		
			Status
		
		
	

	
	
	
		

			upstream
			
				INFO: task hung in nilfs_transaction_begin
					nilfs
			
			1
			
			
			
			1
			906d
			
				
					906d
				
			
			
			
			
				0/29
			
			
				
					
						auto-obsoleted due to no activity on 2024/04/23 10:04
					
				
			
			
		

	
		

			upstream
			
				INFO: task hung in nilfs_transaction_begin (2)
					prio:low
					nilfs
			
			1
			C
			error
			
			14
			41d
			
				
					81d
				
			
			
			
			
				29/29
			
			
				
					
						fixed on 2026/07/15 08:27
					
				
			
			
		

	
	





			
			
			
			
		

	

	
	

		

			▶
			▼
			Last patch testing requests (2)
		

		

			
			

	

		
		
		

			
			Created
			Duration
			User
			Patch
			Repo
			
			Result
		

		
		
		
			

				
				2026/07/16 22:05
				
					3h53m
				
				
					
						joshua.crofts1@gmail.com
					
				
				patch
				git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 58717b2a1365
				
				
					
						
					
					
					
						log
					
					
					
				
			

		
			

				
				2026/07/16 11:19
				
					6h01m
				
				
					
						joshua.crofts1@gmail.com
					
				
				patch
				upstream
				
				
					
						
					
					
					
						log
					
					
					
				
			

		
		
	



			
			
			
		

	

	

	
	
Sample crash report:

	
INFO: task syz.3.20:6062 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20        state:D
 stack:25640 pid:6062  tgid:6052  ppid:5793   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
 rwsem_down_read_slowpath+0x6ba/0x920 kernel/locking/rwsem.c:1114
 __down_read_common kernel/locking/rwsem.c:1291 [inline]
 __down_read kernel/locking/rwsem.c:1304 [inline]
 down_read+0x9c/0x330 kernel/locking/rwsem.c:1576
 nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
 nilfs_mkdir+0xd6/0x390 fs/nilfs2/namei.c:228
 vfs_mkdir+0x406/0x620 fs/namei.c:5276
 filename_mkdirat+0x285/0x510 fs/namei.c:5309
 __do_sys_mkdirat fs/namei.c:5330 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1613b9de59
RSP: 002b:00007f16131fe028 EFLAGS: 00000246
 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f1613e26090 RCX: 00007f1613b9de59
RDX: 00000000000001c0 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f1613c33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1613e26128 R14: 00007f1613e26090 R15: 00007ffd7ee97478
 </TASK>
INFO: task syz.2.19:6076 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:26920 pid:6076  tgid:6073  ppid:5797   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
 rwsem_down_read_slowpath+0x6ba/0x920 kernel/locking/rwsem.c:1114
 __down_read_common kernel/locking/rwsem.c:1291 [inline]
 __down_read kernel/locking/rwsem.c:1304 [inline]
 down_read+0x9c/0x330 kernel/locking/rwsem.c:1576
 nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
 nilfs_mkdir+0xd6/0x390 fs/nilfs2/namei.c:228
 vfs_mkdir+0x406/0x620 fs/namei.c:5276
 filename_mkdirat+0x285/0x510 fs/namei.c:5309
 __do_sys_mkdirat fs/namei.c:5330 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb9c39de59
RSP: 002b:00007feb9d17e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007feb9c626090 RCX: 00007feb9c39de59
RDX: 00000000000001c0 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007feb9c433e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feb9c626128 R14: 00007feb9c626090 R15: 00007fff8cce9fb8
 </TASK>
INFO: task syz.0.17:6080 blocked for more than 149 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D
 stack:25640 pid:6080  tgid:6077  ppid:5784   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
 rwsem_down_read_slowpath+0x6ba/0x920 kernel/locking/rwsem.c:1114
 __down_read_common kernel/locking/rwsem.c:1291 [inline]
 __down_read kernel/locking/rwsem.c:1304 [inline]
 down_read+0x9c/0x330 kernel/locking/rwsem.c:1576
 nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
 nilfs_mkdir+0xd6/0x390 fs/nilfs2/namei.c:228
 vfs_mkdir+0x406/0x620 fs/namei.c:5276
 filename_mkdirat+0x285/0x510 fs/namei.c:5309
 __do_sys_mkdirat fs/namei.c:5330 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f172919de59
RSP: 002b:00007f172a11e028 EFLAGS: 00000246
 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f1729426090 RCX: 00007f172919de59
RDX: 00000000000001c0 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f1729233e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1729426128 R14: 00007f1729426090 R15: 00007ffcc8738ab8
 </TASK>
INFO: task syz.5.22:6086 blocked for more than 153 seconds.
      Not tainted syzkaller #0



	

	



	Crashes (2):
		
		

			Time
			Kernel
			Commit
			Syzkaller
			Config
			Log
			Report
			Syz repro
			C repro
			VM info
			Assets (help?)
			Manager
			Title
		

		
		
		
		

			2026/07/15 21:18
			upstream
			58717b2a1365
			209f0369
			.config
			console log
			report
			syz / log
			C
			
			
				[disk image]
			
				[vmlinux]
			
				[kernel image]
			
				[mounted in repro]
			
			ci-upstream-kasan-gce-root
			INFO: task hung in nilfs_transaction_begin
		

		
		

			2026/07/15 17:06
			upstream
			58717b2a1365
			209f0369
			.config
			console log
			report
			
			
			info
			
				[disk image]
			
				[vmlinux]
			
				[kernel image]
			
			ci-upstream-kasan-gce-root
			INFO: task hung in nilfs_transaction_begin
		

		
		


* Struck through repros no longer work on HEAD.