syzbot


INFO: task hung in del_device_store

Status: upstream: reported C repro on 2025/11/21 00:14
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+9e1ed60c6f288bc7b286@syzkaller.appspotmail.com
First crash: 62d, last: 8d03h
Bug presence (2)
Date Name Commit Repro Result
2025/11/25 upstream (ToT) 30f09200cc4a C [report] INFO: task hung in corrupted
2026/01/09 upstream (ToT) 372800cb95a3 C Failed due to an error; will retry later
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in del_device_store (2) origin:upstream 1 syz 3 8d18h 17d 0/3 upstream: reported syz repro on 2026/01/05 21:06
linux-5.15 INFO: task hung in del_device_store 1 42 188d 560d 0/3 auto-obsoleted due to no activity on 2025/10/26 20:35
linux-5.15 INFO: task hung in del_device_store (2) 1 5 3d02h 63d 0/3 upstream: reported on 2025/11/20 15:49
linux-6.1 INFO: task hung in del_device_store 1 31 155d 566d 0/3 auto-obsoleted due to no activity on 2025/11/28 01:25
upstream INFO: task hung in del_device_store net 1 C error 1959 2d17h 1054d 0/29 upstream: reported C repro on 2023/03/05 17:44
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/12/25 17:29 2h16m bisect fix linux-6.6.y OK (0) job log log

Sample crash report:
INFO: task syz-executor:5898 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22184 pid:5898  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209
 kernfs_fop_write_iter+0x3b6/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x43b/0x940 fs/read_write.c:584
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f87dd78e1ff
RSP: 002b:00007fffacbb0190 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f87dd78e1ff
RDX: 0000000000000001 RSI: 00007fffacbb01e0 RDI: 0000000000000005
RBP: 00007f87dd8152cb R08: 0000000000000000 R09: 00007fffacbaffe7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fffacbb01e0 R14: 00007f87de514620 R15: 0000000000000003
 </TASK>
INFO: task syz-executor:5903 blocked for more than 150 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22280 pid:5903  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675
 device_remove drivers/base/dd.c:567 [inline]
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x468/0x7a0 drivers/base/dd.c:1295
 bus_remove_device+0x342/0x400 drivers/base/bus.c:576
 device_del+0x50b/0x900 drivers/base/core.c:3872
 device_unregister+0x20/0xc0 drivers/base/core.c:3913
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline]
 del_device_store+0x2ab/0x360 drivers/net/netdevsim/bus.c:219
 kernfs_fop_write_iter+0x3b6/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x43b/0x940 fs/read_write.c:584
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcfaed8e1ff
RSP: 002b:00007fff39715930 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fcfaed8e1ff
RDX: 0000000000000001 RSI: 00007fff39715980 RDI: 0000000000000005
RBP: 00007fcfaee152cb R08: 0000000000000000 R09: 00007fff39715787
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fff39715980 R14: 00007fcfafb14620 R15: 0000000000000003
 </TASK>
INFO: task syz-executor:5905 blocked for more than 150 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22280 pid:5905  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 del_device_store+0xd2/0x360 drivers/net/netdevsim/bus.c:209
 kernfs_fop_write_iter+0x3b6/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x43b/0x940 fs/read_write.c:584
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/14 20:26 linux-6.6.y c596736dadab d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in del_device_store
2025/11/21 16:29 linux-6.6.y 0a805b6ea8cd 280ea308 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in del_device_store
2025/11/21 00:13 linux-6.6.y 0a805b6ea8cd 2cc4c24a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in del_device_store
* Struck through repros no longer work on HEAD.