INFO: task hung in scsi_scan_host_selected

Status: premoderation: reported syz repro on 2026/10/12 06:04
Reported-by: syzbot+5a10267f8fae34be9f64@syzkaller.appspotmail.com
First crash: 1d08h, last: 1d08h
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in scsi_scan_host_selected prio:low scsi 1 syz, C error 16 4d12h 39d 0/29 upstream: reported C repro on 2026/09/03 15:13

Sample crash report:
INFO: task syz.1.31:468 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.31        state:D stack:0     pid:468   tgid:468   ppid:456    flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x16fe/0x23d0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8032
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 scsi_scan_host_selected+0x15f/0x610 drivers/scsi/scsi_scan.c:1863
 scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
 store_scan+0x4ba/0x550 drivers/scsi/scsi_sysfs.c:191
 dev_attr_store+0x73/0xa0 drivers/base/core.c:2440
 sysfs_kf_write+0x141/0x160 fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x75f/0xfd0 fs/read_write.c:684
 ksys_write+0x145/0x260 fs/read_write.c:737
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x7f/0x90 fs/read_write.c:746
 x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f438bf9e1d9
RSP: 002b:00007ffec84ff5a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f438c225fa0 RCX: 00007f438bf9e1d9
RDX: 0000000000000005 RSI: 0000200000000380 RDI: 0000000000000003
RBP: 00007f438c035888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f438c225fac R14: 00007f438c225fa0 R15: 00007f438c225fa0
 </TASK>
INFO: task syz.6.32:469 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.32        state:D stack:0     pid:469   tgid:469   ppid:457    flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x16fe/0x23d0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8032
 __mutex_lock_common kernel/locking/mutex.c:707 [inline]
 __mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
 scsi_scan_host_selected+0x15f/0x610 drivers/scsi/scsi_scan.c:1863
 scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline]
 store_scan+0x4ba/0x550 drivers/scsi/scsi_sysfs.c:191
 dev_attr_store+0x73/0xa0 drivers/base/core.c:2440
 sysfs_kf_write+0x141/0x160 fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x316/0x510 fs/kernfs/file.c:352
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x75f/0xfd0 fs/read_write.c:684
 ksys_write+0x145/0x260 fs/read_write.c:737
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x7f/0x90 fs/read_write.c:746
 x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fb42a19e1d9
RSP: 002b:00007ffcc293f5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb42a425fa0 RCX: 00007fb42a19e1d9
RDX: 0000000000000005 RSI: 0000200000000380 RDI: 0000000000000003
RBP: 00007fb42a235888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb42a425fac R14: 00007fb42a425fa0 R15: 00007fb42a425fa0
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 9109b4058d136ef0ac9398910d6f8e272823abe4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:114
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:63
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 cpumask_backtrace+0x1f/0x30 lib/nmi_backtrace.c:127
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xe45/0xf90 kernel/hung_task.c:423
 kthread+0x2c7/0x360 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 9109b4058d136ef0ac9398910d6f8e272823abe4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:116
Code: cc cc cc cc cc cc cc b8 a4 14 4a 50 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 39 3f 00 55 48 89 e5 fb f4 <5d> c3 cc cc cc cc cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90
RSP: 0018:ffffffff87c07da0 EFLAGS: 000002c2
RAX: ffff8881f6c00000 RBX: ffffffff87c156c0 RCX: ffffffff85a8253d
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 00000000000c5c9c
RBP: ffffffff87c07da0 R08: ffff8881f6c396fb R09: 1ffff1103ed872df
R10: dffffc0000000000 R11: ffffed103ed872e0 R12: 0000000000000000
R13: 1ffffffff0f82ad8 R14: dffffc0000000000 R15: ffffffff886d5868
FS:  0000000000000000(0000) GS:ffff8881f6c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555570fac4e8 CR3: 000000010d3f2000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:-1 [inline]
 default_idle+0x17/0x30 arch/x86/kernel/process.c:754
 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:791
 default_idle_call+0x3e/0x80 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:193 [inline]
 do_idle+0x1df/0x570 kernel/sched/idle.c:346
 cpu_startup_entry+0x47/0x60 kernel/sched/idle.c:445
 rest_init+0x10b/0x130 init/main.c:760
 start_kernel+0x462/0x4bb init/main.c:1242
 x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:507
 x86_64_start_kernel+0x6a/0x7b arch/x86/kernel/head64.c:488
 common_startup_64+0x13b/0x157
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/12 06:03 android16-6.12 c82b35cb007f 4f92358f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in scsi_scan_host_selected
* Struck through repros no longer work on HEAD.