Extracting prog: 6m47.256278515s Minimizing prog: 54m49.744320232s Simplifying prog options: 14m25.038551981s Extracting C: 5m11.487620379s 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: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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program crashed: INFO: task hung in bdev_release program crashed: INFO: task hung in bdev_release single: successfully extracted reproducer found reproducer with 6 syscalls minimizing guilty program testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)) ioctl$NBD_DO_IT(r1, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) ioctl$NBD_SET_SOCK(r1, 0xab00, 0xffffffffffffffff) ioctl$NBD_DO_IT(r1, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(0xffffffffffffffff, 0xab00, r1) ioctl$NBD_DO_IT(0xffffffffffffffff, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) r0 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r0, 0xab00, r1) ioctl$NBD_DO_IT(r0, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: ioctl$NBD_SET_SIZE_BLOCKS(0xffffffffffffffff, 0xab07, 0xb) r0 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r0, 0xab00, r1) ioctl$NBD_DO_IT(r0, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(0x0, 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(0x0, 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program did not crash testing program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, 0x0) ioctl$NBD_SET_SOCK(r1, 0xab00, 0xffffffffffffffff) ioctl$NBD_DO_IT(r1, 0xab03) program did not crash extracting C reproducer testing compiled C program (duration=6m0s, {Threaded:true 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT program crashed: no output from test machine a never seen crash title: no output from test machine, ignore simplifying guilty program options testing 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program did not crash 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}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program crashed: INFO: task hung in bdev_release extracting C reproducer testing compiled C 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}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT program crashed: no output from test machine a never seen crash title: no output from test machine, 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}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program crashed: INFO: task hung in bdev_release validation run: crashed=true 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}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program crashed: INFO: task hung in bdev_release validation run: crashed=true 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}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT detailed listing: executing program 0: r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0) ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xb) r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0) socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={0xffffffffffffffff}) ioctl$NBD_SET_SOCK(r1, 0xab00, r2) ioctl$NBD_DO_IT(r1, 0xab03) program crashed: INFO: task hung in bdev_release validation run: crashed=true reproducing took 1h30m43.15410072s repro crashed as (corrupted=false): INFO: task syz.0.17:5863 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27368 pid:5863 tgid:5863 ppid:5761 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 bdev_release+0x15a/0x6d0 block/bdev.c:1131 blkdev_release+0x15/0x20 block/fops.c:680 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5952b9de59 RSP: 002b:00007fffe32ce8d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f5952e27da0 RCX: 00007f5952b9de59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f5952e27da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f5952e27cb0 R11: 0000000000000246 R12: 000000000002455f R13: 00007f5952e25fac R14: 000000000002427a R15: 00007fffe32ce9e0 INFO: task syz.0.17:5864 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:26872 pid:5864 tgid:5863 ppid:5761 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 bdev_release+0x15a/0x6d0 block/bdev.c:1131 blkdev_release+0x15/0x20 block/fops.c:680 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5952b9de59 RSP: 002b:00007f5953a79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f5952e25fa0 RCX: 00007f5952b9de59 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 00007f5952c33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5952e26038 R14: 00007f5952e25fa0 R15: 00007fffe32ce778 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5376: #0: ffff8880376570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5644: #0: ffff888027f95350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5646: #0: ffff888027fe1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5647: #0: ffff888027f91350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5648: #0: ffff888027edd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.0.17/5863: #0: ffff888027edd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.0.17/5864: #0: ffff888027edd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.1.18/5899: #0: ffff888027f91350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.1.18/5901: #0: ffff888027f91350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.2.19/5943: #0: ffff888027f95350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.2.19/5944: #0: ffff888027f95350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.3.20/5979: #0: ffff888027fe1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.3.20/5980: #0: ffff888027fe1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/5984: #0: ffff8880285f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5986: #0: ffff888027fe5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.4.21/6023: #0: ffff888027fe5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.4.21/6024: #0: ffff888027fe5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6029: #0: ffff8880284f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.5.22/6066: #0: ffff8880284f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.5.22/6067: #0: ffff8880284f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6078: #0: ffff8880284f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.6.23/6116: #0: ffff8880284f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.6.23/6118: #0: ffff8880284f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.7.24/6159: #0: ffff8880285f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.7.24/6160: #0: ffff8880285f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6161: #0: ffff8880285f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.8.25/6202: #0: ffff8880285f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.8.25/6203: #0: ffff8880285f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6204: #0: ffff888028681350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.9.26/6246: #0: ffff888028681350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.9.26/6247: #0: ffff888028681350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 76 8d 02 c3 cc cc cc cc 0f 1f 00 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 c3 39 12 00 fb f4 bc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e807e10 EFLAGS: 00000246 RAX: 00000000001d908d RBX: ffffffff8e891480 RCX: ffffffff8bb962d5 RDX: 0000000000000000 RSI: ffffffff8e1a3c59 RDI: ffffffff8c400f80 RBP: fffffbfff1d12290 R08: 0000000000000001 R09: ffffed101708678d R10: ffff8880b8433c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1d00fc6 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123de8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056419761f168 CR3: 000000007310b000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158 final repro crashed as (corrupted=false): INFO: task syz.0.17:5863 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27368 pid:5863 tgid:5863 ppid:5761 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 bdev_release+0x15a/0x6d0 block/bdev.c:1131 blkdev_release+0x15/0x20 block/fops.c:680 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5952b9de59 RSP: 002b:00007fffe32ce8d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f5952e27da0 RCX: 00007f5952b9de59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f5952e27da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f5952e27cb0 R11: 0000000000000246 R12: 000000000002455f R13: 00007f5952e25fac R14: 000000000002427a R15: 00007fffe32ce9e0 INFO: task syz.0.17:5864 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:26872 pid:5864 tgid:5863 ppid:5761 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 bdev_release+0x15a/0x6d0 block/bdev.c:1131 blkdev_release+0x15/0x20 block/fops.c:680 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5952b9de59 RSP: 002b:00007f5953a79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f5952e25fa0 RCX: 00007f5952b9de59 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 00007f5952c33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5952e26038 R14: 00007f5952e25fa0 R15: 00007fffe32ce778 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5376: #0: ffff8880376570a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5644: #0: ffff888027f95350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5646: #0: ffff888027fe1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5647: #0: ffff888027f91350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5648: #0: ffff888027edd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.0.17/5863: #0: ffff888027edd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.0.17/5864: #0: ffff888027edd350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.1.18/5899: #0: ffff888027f91350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.1.18/5901: #0: ffff888027f91350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.2.19/5943: #0: ffff888027f95350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.2.19/5944: #0: ffff888027f95350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.3.20/5979: #0: ffff888027fe1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.3.20/5980: #0: ffff888027fe1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/5984: #0: ffff8880285f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by udevd/5986: #0: ffff888027fe5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.4.21/6023: #0: ffff888027fe5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.4.21/6024: #0: ffff888027fe5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6029: #0: ffff8880284f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.5.22/6066: #0: ffff8880284f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.5.22/6067: #0: ffff8880284f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6078: #0: ffff8880284f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.6.23/6116: #0: ffff8880284f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.6.23/6118: #0: ffff8880284f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.7.24/6159: #0: ffff8880285f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.7.24/6160: #0: ffff8880285f1350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6161: #0: ffff8880285f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.8.25/6202: #0: ffff8880285f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.8.25/6203: #0: ffff8880285f5350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by udevd/6204: #0: ffff888028681350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:948 1 lock held by syz.9.26/6246: #0: ffff888028681350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 1 lock held by syz.9.26/6247: #0: ffff888028681350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1131 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 76 8d 02 c3 cc cc cc cc 0f 1f 00 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 c3 39 12 00 fb f4 bc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e807e10 EFLAGS: 00000246 RAX: 00000000001d908d RBX: ffffffff8e891480 RCX: ffffffff8bb962d5 RDX: 0000000000000000 RSI: ffffffff8e1a3c59 RDI: ffffffff8c400f80 RBP: fffffbfff1d12290 R08: 0000000000000001 R09: ffffed101708678d R10: ffff8880b8433c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1d00fc6 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123de8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056419761f168 CR3: 000000007310b000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158