Extracting prog: 7m52.498267323s
Minimizing prog: 24m30.202139545s
Simplifying prog options: 0s
Extracting C: 3m12.271859815s
Simplifying C: 27m21.057562355s
extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000080), 0x162e02, 0x0)
r1 = dup(r0)
fallocate(r1, 0x10, 0x0, 0x2000000400)
program did not crash
single: failed to extract reproducer
single: executing 1 programs separately with timeout 1m40s
testing program (duration=1m40s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000080), 0x162e02, 0x0)
r1 = dup(r0)
fallocate(r1, 0x10, 0x0, 0x2000000400)
program crashed: lost connection to test machine
suppressed program crash: lost connection to test machine
single: failed to extract reproducer
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000080), 0x162e02, 0x0)
r1 = dup(r0)
fallocate(r1, 0x10, 0x0, 0x2000000400)
program crashed: INFO: task hung in blkdev_fallocate
single: successfully extracted reproducer
found reproducer with 3 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000080), 0x162e02, 0x0)
dup(r0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-fallocate
detailed listing:
executing program 0:
openat$nullb(0xffffffffffffff9c, &(0x7f0000000080), 0x162e02, 0x0)
fallocate(0xffffffffffffffff, 0x10, 0x0, 0x2000000400)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): dup-fallocate
detailed listing:
executing program 0:
r0 = dup(0xffffffffffffffff)
fallocate(r0, 0x10, 0x0, 0x2000000400)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
detailed listing:
executing program 0:
r0 = openat$nullb(0xffffffffffffff9c, 0x0, 0x162e02, 0x0)
r1 = dup(r0)
fallocate(r1, 0x10, 0x0, 0x2000000400)
program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
simplifying C reproducer
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:namespace SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:namespace 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:true Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:false Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
testing compiled C program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$nullb-dup-fallocate
program crashed: INFO: task hung in blkdev_fallocate
reproducing took 1h2m56.029869043s
repro crashed as (corrupted=false):
INFO: task syz-executor194:5852 blocked for more than 143 seconds.
Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor194 state:D stack:28008 pid:5852 tgid:5852 ppid:5851 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
INFO: task syz-executor194:5854 blocked for more than 143 seconds.
Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor194 state:D stack:27288 pid:5854 tgid:5854 ppid:5853 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
INFO: task syz-executor194:5856 blocked for more than 144 seconds.
Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor194 state:D stack:27240 pid:5856 tgid:5856 ppid:5855 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
1 lock held by klogd/5195:
2 locks held by getty/5597:
#0: ffff8880308b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by syz-executor194/5850:
1 lock held by syz-executor194/5852:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
1 lock held by syz-executor194/5854:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
1 lock held by syz-executor194/5856:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
1 lock held by syz-executor194/5872:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5850 Comm: syz-executor194 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:745
Code: e8 db 89 bd 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 60 5c b9 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 ec b1 7c 00 48 c7 c3 58 3f 9d 92 49 03 1e 48 89
RSP: 0018:ffffc9000445ee70 EFLAGS: 00000246
RAX: 1ffffffff1b72b8c RBX: 0000000000000000 RCX: 77d61a1ddf9e8a00
RDX: ffffc9000445f001 RSI: ffffffff8be27520 RDI: ffffffff8be274e0
RBP: dffffc0000000000 R08: ffffc9000445f3e8 R09: 0000000000000000
R10: ffffc9000445f018 R11: fffff5200088be05 R12: ffffc9000445f3f8
R13: ffffffff81729e15 R14: ffffffff8db95c60 R15: dffffc0000000000
FS: 0000555570cc1380(0000) GS:ffff888125c5f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd129eb0700 CR3: 0000000074078000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5882
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2341 [inline]
slab_free mm/slub.c:4642 [inline]
kmem_cache_free+0x2f6/0x400 mm/slub.c:4744
__bio_chain_endio block/bio.c:319 [inline]
bio_endio+0x3f/0x870 block/bio.c:1628
blk_update_request+0x5eb/0xe70 block/blk-mq.c:987
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1149
nullb_complete_cmd drivers/block/null_blk/main.c:1402 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1454 [inline]
null_queue_rq+0xbfe/0xe30 drivers/block/null_blk/main.c:1693
null_queue_rqs+0x123/0x270 drivers/block/null_blk/main.c:1707
__blk_mq_flush_list block/blk-mq.c:2826 [inline]
blk_mq_dispatch_queue_requests+0x414/0x800 block/blk-mq.c:2871
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2959
blk_add_rq_to_plug+0x175/0x450 block/blk-mq.c:1388
blk_mq_submit_bio+0xbd3/0x22d0 block/blk-mq.c:3208
__submit_bio+0x207/0x5a0 block/blk-core.c:635
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x505/0xb50 block/blk-core.c:751
bio_chain_and_submit+0xeb/0x130 block/bio.c:362
__blkdev_issue_zero_pages+0x24f/0x2c0 block/blk-lib.c:222
blkdev_issue_zero_pages block/blk-lib.c:238 [inline]
blkdev_issue_zeroout+0x56c/0x7c0 block/blk-lib.c:325
blkdev_fallocate+0x3e6/0x4b0 block/fops.c:-1
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.857 msecs
final repro crashed as (corrupted=false):
INFO: task syz-executor194:5852 blocked for more than 143 seconds.
Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor194 state:D stack:28008 pid:5852 tgid:5852 ppid:5851 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
INFO: task syz-executor194:5854 blocked for more than 143 seconds.
Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor194 state:D stack:27288 pid:5854 tgid:5854 ppid:5853 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
INFO: task syz-executor194:5856 blocked for more than 144 seconds.
Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor194 state:D stack:27240 pid:5856 tgid:5856 ppid:5855 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
1 lock held by klogd/5195:
2 locks held by getty/5597:
#0: ffff8880308b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by syz-executor194/5850:
1 lock held by syz-executor194/5852:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
1 lock held by syz-executor194/5854:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
1 lock held by syz-executor194/5856:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
1 lock held by syz-executor194/5872:
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022d12a20 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_fallocate+0x1d8/0x4b0 block/fops.c:877
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5850 Comm: syz-executor194 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:745
Code: e8 db 89 bd 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 60 5c b9 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 ec b1 7c 00 48 c7 c3 58 3f 9d 92 49 03 1e 48 89
RSP: 0018:ffffc9000445ee70 EFLAGS: 00000246
RAX: 1ffffffff1b72b8c RBX: 0000000000000000 RCX: 77d61a1ddf9e8a00
RDX: ffffc9000445f001 RSI: ffffffff8be27520 RDI: ffffffff8be274e0
RBP: dffffc0000000000 R08: ffffc9000445f3e8 R09: 0000000000000000
R10: ffffc9000445f018 R11: fffff5200088be05 R12: ffffc9000445f3f8
R13: ffffffff81729e15 R14: ffffffff8db95c60 R15: dffffc0000000000
FS: 0000555570cc1380(0000) GS:ffff888125c5f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd129eb0700 CR3: 0000000074078000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5882
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2341 [inline]
slab_free mm/slub.c:4642 [inline]
kmem_cache_free+0x2f6/0x400 mm/slub.c:4744
__bio_chain_endio block/bio.c:319 [inline]
bio_endio+0x3f/0x870 block/bio.c:1628
blk_update_request+0x5eb/0xe70 block/blk-mq.c:987
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1149
nullb_complete_cmd drivers/block/null_blk/main.c:1402 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1454 [inline]
null_queue_rq+0xbfe/0xe30 drivers/block/null_blk/main.c:1693
null_queue_rqs+0x123/0x270 drivers/block/null_blk/main.c:1707
__blk_mq_flush_list block/blk-mq.c:2826 [inline]
blk_mq_dispatch_queue_requests+0x414/0x800 block/blk-mq.c:2871
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2959
blk_add_rq_to_plug+0x175/0x450 block/blk-mq.c:1388
blk_mq_submit_bio+0xbd3/0x22d0 block/blk-mq.c:3208
__submit_bio+0x207/0x5a0 block/blk-core.c:635
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x505/0xb50 block/blk-core.c:751
bio_chain_and_submit+0xeb/0x130 block/bio.c:362
__blkdev_issue_zero_pages+0x24f/0x2c0 block/blk-lib.c:222
blkdev_issue_zero_pages block/blk-lib.c:238 [inline]
blkdev_issue_zeroout+0x56c/0x7c0 block/blk-lib.c:325
blkdev_fallocate+0x3e6/0x4b0 block/fops.c:-1
vfs_fallocate+0x6a0/0x830 fs/open.c:341
ksys_fallocate fs/open.c:365 [inline]
__do_sys_fallocate fs/open.c:370 [inline]
__se_sys_fallocate fs/open.c:368 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cd70feb29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffee02889b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6cd70feb29
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffee0288bd8 R14: 00007ffee02889e0 R15: 00007ffee02889d0
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.857 msecs