Extracting prog: 8m13.324218096s
Minimizing prog: 1h1m23.23259853s
Simplifying prog options: 6m48.168895036s
Extracting C: 3m13.884178809s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program crashed: INFO: task hung in do_get_write_access
program crashed: INFO: task hung in __rq_qos_throttle
single: successfully extracted reproducer
found reproducer with 4 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
pwrite64(0xffffffffffffffff, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mount-openat-pwrite64
detailed listing:
executing program 0:
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, 0x0, 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, 0x0, &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', 0x0, 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, 0x0, 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, 0x0, 0x0, 0x4)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0), 0x0, 0x4)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
program crashed: INFO: task hung in do_get_write_access
a never seen crash title: INFO: task hung in do_get_write_access, ignore
simplifying guilty program options
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program crashed: INFO: task hung in do_get_write_access
a never seen crash title: INFO: task hung in do_get_write_access, ignore
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program crashed: INFO: task hung in do_get_write_access
a never seen crash title: INFO: task hung in do_get_write_access, ignore
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program crashed: INFO: task hung in do_get_write_access
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program crashed: INFO: task hung in __rq_qos_throttle
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): mkdirat-mount-openat-pwrite64
detailed listing:
executing program 0:
mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./sys\x00', 0x1ff)
mount(0x0, &(0x7f0000000000)='./sys\x00', &(0x7f0000000040)='sysfs\x00', 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='./sys/bus/pci/devices/0000:00:03.0/config\x00', 0x2, 0x0)
pwrite64(r0, &(0x7f00000000c0)="02", 0x500, 0x4)

program crashed: INFO: task hung in __rq_qos_throttle
validation run: crashed=true
reproducing took 1h29m44.518472848s
repro crashed as (corrupted=false):
INFO: task kworker/u8:2:40 blocked in I/O wait for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:21480 pid:40    tgid:40    ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5584 [inline]
 __schedule+0x1b47/0x5b40 kernel/sched/core.c:7387
 __schedule_loop kernel/sched/core.c:7464 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7479
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8151
 rq_qos_wait+0x266/0x360 block/blk-rq-qos.c:307
 __wbt_wait block/blk-wbt.c:598 [inline]
 wbt_wait+0x326/0x550 block/blk-wbt.c:658
 __rq_qos_throttle+0x6b/0xb0 block/blk-rq-qos.c:66
 rq_qos_throttle block/blk-rq-qos.h:164 [inline]
 blk_mq_get_new_requests block/blk-mq.c:3046 [inline]
 blk_mq_submit_bio+0x165d/0x2bb0 block/blk-mq.c:3182
 __submit_bio_noacct_mq block/blk-core.c:757 [inline]
 submit_bio_noacct_nocheck+0x34e/0xa40 block/blk-core.c:791
 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline]
 ext4_io_submit fs/ext4/page-io.c:396 [inline]
 io_submit_add_bh fs/ext4/page-io.c:452 [inline]
 ext4_bio_write_folio+0x101a/0x18c0 fs/ext4/page-io.c:547
 mpage_map_and_submit_buffers fs/ext4/inode.c:2331 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2515 [inline]
 ext4_do_writepages+0x203d/0x4770 fs/ext4/inode.c:2938
 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3032
 do_writepages+0x338/0x560 mm/page-writeback.c:2560
 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1800
 writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2111
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2187
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2298
 wb_check_old_data_flush fs/fs-writeback.c:2402 [inline]
 wb_do_writeback fs/fs-writeback.c:2481 [inline]
 wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2509
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/34: 1, last CPU#1:
 #0: ffffffff8f15a2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8f15a2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8f15a2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:2/40: 5, on CPU#1:
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #2: ffff888034f920e8 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:670
 #3: ffff888034f90c98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3031
 #4: ffff888035146938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
locks held by getty/5367: 2, on CPU#0:
 #0: ffff8880286610a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5647: 2, on CPU#1:
 #0: ffff888074847308 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.3.176/6280: 2, on CPU#0:
 #0: ffff888077514808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.2.177/6281: 2, on CPU#0:
 #0: ffff88802c906e48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.1.178/6282: 2, on CPU#1:
 #0: ffff88802c554bc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.0.179/6283: 2, on CPU#0:
 #0: ffff8880753f1588 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
 watchdog+0x1073/0x10f0 kernel/hung_task.c:598
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: db a4 02 e9 03 18 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 09 2a 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8ee07ca0 EFLAGS: 00000242
RAX: 000000000012dd5b RBX: ffffffff819c5e9c RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e772168 RDI: ffffffff8c8f4880
RBP: ffffffff8ee07d78 R08: ffff8880b8433e5b R09: 1ffff110170867cb
R10: dffffc0000000000 R11: ffffed10170867cc R12: 0000000000000000
R13: 1ffffffff1dd1df8 R14: 1ffffffff1dc0f9c R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888124632000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005596780ec660 CR3: 000000000ef48000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/kernel/process.c:767 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:768
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x1cc/0x540 kernel/sched/idle.c:355
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
 rest_init+0x378/0x3a0 init/main.c:729
 start_kernel+0x397/0x3e0 init/main.c:1188
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x157
 </TASK>

final repro crashed as (corrupted=false):
INFO: task kworker/u8:2:40 blocked in I/O wait for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:21480 pid:40    tgid:40    ppid:2      task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5584 [inline]
 __schedule+0x1b47/0x5b40 kernel/sched/core.c:7387
 __schedule_loop kernel/sched/core.c:7464 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7479
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8151
 rq_qos_wait+0x266/0x360 block/blk-rq-qos.c:307
 __wbt_wait block/blk-wbt.c:598 [inline]
 wbt_wait+0x326/0x550 block/blk-wbt.c:658
 __rq_qos_throttle+0x6b/0xb0 block/blk-rq-qos.c:66
 rq_qos_throttle block/blk-rq-qos.h:164 [inline]
 blk_mq_get_new_requests block/blk-mq.c:3046 [inline]
 blk_mq_submit_bio+0x165d/0x2bb0 block/blk-mq.c:3182
 __submit_bio_noacct_mq block/blk-core.c:757 [inline]
 submit_bio_noacct_nocheck+0x34e/0xa40 block/blk-core.c:791
 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline]
 ext4_io_submit fs/ext4/page-io.c:396 [inline]
 io_submit_add_bh fs/ext4/page-io.c:452 [inline]
 ext4_bio_write_folio+0x101a/0x18c0 fs/ext4/page-io.c:547
 mpage_map_and_submit_buffers fs/ext4/inode.c:2331 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2515 [inline]
 ext4_do_writepages+0x203d/0x4770 fs/ext4/inode.c:2938
 ext4_writepages+0x1fe/0x4e0 fs/ext4/inode.c:3032
 do_writepages+0x338/0x560 mm/page-writeback.c:2560
 __writeback_single_inode+0x136/0x1220 fs/fs-writeback.c:1800
 writeback_sb_inodes+0x9de/0x1af0 fs/fs-writeback.c:2111
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2187
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2298
 wb_check_old_data_flush fs/fs-writeback.c:2402 [inline]
 wb_do_writeback fs/fs-writeback.c:2481 [inline]
 wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2509
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/34: 1, last CPU#1:
 #0: ffffffff8f15a2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8f15a2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8f15a2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/u8:2/40: 5, on CPU#1:
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #0: ffff888020a8d948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
 #1: ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
 #2: ffff888034f920e8 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:670
 #3: ffff888034f90c98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3031
 #4: ffff888035146938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444
locks held by getty/5367: 2, on CPU#0:
 #0: ffff8880286610a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5647: 2, on CPU#1:
 #0: ffff888074847308 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.3.176/6280: 2, on CPU#0:
 #0: ffff888077514808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.2.177/6281: 2, on CPU#0:
 #0: ffff88802c906e48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.1.178/6282: 2, on CPU#1:
 #0: ffff88802c554bc8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898
locks held by syz.0.179/6283: 2, on CPU#0:
 #0: ffff8880753f1588 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
 #1: ffff888034f92558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
 watchdog+0x1073/0x10f0 kernel/hung_task.c:598
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: db a4 02 e9 03 18 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 09 2a 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8ee07ca0 EFLAGS: 00000242
RAX: 000000000012dd5b RBX: ffffffff819c5e9c RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e772168 RDI: ffffffff8c8f4880
RBP: ffffffff8ee07d78 R08: ffff8880b8433e5b R09: 1ffff110170867cb
R10: dffffc0000000000 R11: ffffed10170867cc R12: 0000000000000000
R13: 1ffffffff1dd1df8 R14: 1ffffffff1dc0f9c R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888124632000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005596780ec660 CR3: 000000000ef48000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/kernel/process.c:767 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:768
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x1cc/0x540 kernel/sched/idle.c:355
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
 rest_init+0x378/0x3a0 init/main.c:729
 start_kernel+0x397/0x3e0 init/main.c:1188
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x157
 </TASK>