Extracting prog: 5m4.587123772s Minimizing prog: 30m46.815606838s Simplifying prog options: 16m40.226976553s Extracting C: 5m16.103304518s 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}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) program crashed: INFO: task hung in blk_trace_setup single: successfully extracted reproducer found reproducer with 3 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}}): syz_open_dev$sg-ioctl$BLKTRACESETUP detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) 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}}): syz_open_dev$sg-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) 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}}): ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: ioctl$BLKTRACESETUP(0xffffffffffffffff, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(0xffffffffffffffff, 0x1276, 0x20000000) 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}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(0x0, 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) 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}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, 0x0) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) 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}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN program crashed: no output from test machine a never seen crash title: no output from test machine, ignore simplifying guilty program options testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) program crashed: INFO: task hung in blk_trace_setup extracting C reproducer testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN 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$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) program crashed: INFO: task hung in blk_trace_remove 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$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) program crashed: INFO: task hung in blk_trace_setup 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$sg-ioctl$BLKTRACESETUP-ioctl$SG_BLKTRACETEARDOWN detailed listing: executing program 0: r0 = syz_open_dev$sg(&(0x7f0000000000), 0x0, 0x401) ioctl$BLKTRACESETUP(r0, 0xc0481273, &(0x7f0000000b40)={'\x00', 0x8, 0x8000530, 0xc, 0x8000000000000001, 0x59d}) ioctl$SG_BLKTRACETEARDOWN(r0, 0x1276, 0x20000000) program crashed: INFO: task hung in blk_trace_remove validation run: crashed=true reproducing took 1h14m37.640120931s repro crashed as (corrupted=false): INFO: task syz.7.24:6923 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.24 state:D stack:29096 pid:6923 ppid:6901 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 sg_ioctl_common drivers/scsi/sg.c:1123 [inline] sg_ioctl+0x45e/0x21a0 drivers/scsi/sg.c:1157 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f143219de59 RSP: 002b:00007f14330ee028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1432426090 RCX: 00007f143219de59 RDX: 0000000020000000 RSI: 0000000000001276 RDI: 0000000000000003 RBP: 00007f1432233e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1432426128 R14: 00007f1432426090 R15: 00007ffe3bdd7638 Showing all locks held in the system: 3 locks held by kworker/1:1/27: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90000a2fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90000a2fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/29: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:10/3445: #0: ffff88802c9ef938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88802c9ef938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc9000cbf7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000cbf7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4723 2 locks held by kworker/1:3/5162: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90003047d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003047d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 2 locks held by getty/5539: #0: ffff88802de070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 2 locks held by syz.7.24/6922: 1 lock held by syz.7.24/6923: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.8.25/7097: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.8.25/7098: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.9.26/7248: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.9.26/7249: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 5 locks held by kworker/u4:2/7287: #0: ffff88801a25c938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801a25c938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90003617d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003617d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3c8f90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606 #3: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xf2/0xa00 net/core/dev.c:11644 #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by syz.0.27/7450: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.0.27/7452: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.1.28/7816: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.1.28/7818: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.2.29/8204: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.2.29/8205: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.3.30/8497: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.3.30/8499: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.4.31/8898: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.4.31/8900: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz-executor/9165: #0: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473 2 locks held by rm/9180: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1089 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:write_comp_data kernel/kcov.c:244 [inline] RIP: 0010:__sanitizer_cov_trace_cmp4+0x8/0x90 kernel/kcov.c:287 Code: 08 02 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 15 60 d1 7c 7e 65 8b 0d 61 d1 7c 7e 81 e1 00 01 ff 00 74 RSP: 0000:ffffc9000464f5d0 EFLAGS: 00000206 RAX: ffffffff813b25e6 RBX: ffffffff81000000 RCX: ffff888023fd0000 RDX: 0000000000000000 RSI: 00000000000058b2 RDI: 000000000009c000 RBP: 000000000009c000 R08: ffffc9000464f770 R09: 0000000000000006 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000464fbc0 R13: 000000000009c001 R14: 00000000000058b2 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7e802f1f60 CR3: 000000006be62000 CR4: 00000000003506f0 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:211 [inline] unwind_next_frame+0x216/0x2990 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x290 mm/slub.c:3852 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x723/0xa90 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 final repro crashed as (corrupted=false): INFO: task syz.7.24:6923 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.24 state:D stack:29096 pid:6923 ppid:6901 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 sg_ioctl_common drivers/scsi/sg.c:1123 [inline] sg_ioctl+0x45e/0x21a0 drivers/scsi/sg.c:1157 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f143219de59 RSP: 002b:00007f14330ee028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1432426090 RCX: 00007f143219de59 RDX: 0000000020000000 RSI: 0000000000001276 RDI: 0000000000000003 RBP: 00007f1432233e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1432426128 R14: 00007f1432426090 R15: 00007ffe3bdd7638 Showing all locks held in the system: 3 locks held by kworker/1:1/27: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90000a2fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90000a2fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/29: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:10/3445: #0: ffff88802c9ef938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88802c9ef938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc9000cbf7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000cbf7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4723 2 locks held by kworker/1:3/5162: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90003047d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003047d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 2 locks held by getty/5539: #0: ffff88802de070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 2 locks held by syz.7.24/6922: 1 lock held by syz.7.24/6923: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.8.25/7097: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.8.25/7098: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.9.26/7248: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.9.26/7249: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 5 locks held by kworker/u4:2/7287: #0: ffff88801a25c938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801a25c938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90003617d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003617d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3c8f90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606 #3: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xf2/0xa00 net/core/dev.c:11644 #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #4: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by syz.0.27/7450: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.0.27/7452: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.1.28/7816: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.1.28/7818: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.2.29/8204: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.2.29/8205: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.3.30/8497: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.3.30/8499: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz.4.31/8898: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xb2/0x200 kernel/trace/blktrace.c:648 1 lock held by syz.4.31/8900: #0: ffff888022a4bbe8 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:406 1 lock held by syz-executor/9165: #0: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3d5f88 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ed/0xf90 net/core/rtnetlink.c:6473 2 locks held by rm/9180: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1089 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:write_comp_data kernel/kcov.c:244 [inline] RIP: 0010:__sanitizer_cov_trace_cmp4+0x8/0x90 kernel/kcov.c:287 Code: 08 02 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 15 60 d1 7c 7e 65 8b 0d 61 d1 7c 7e 81 e1 00 01 ff 00 74 RSP: 0000:ffffc9000464f5d0 EFLAGS: 00000206 RAX: ffffffff813b25e6 RBX: ffffffff81000000 RCX: ffff888023fd0000 RDX: 0000000000000000 RSI: 00000000000058b2 RDI: 000000000009c000 RBP: 000000000009c000 R08: ffffc9000464f770 R09: 0000000000000006 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000464fbc0 R13: 000000000009c001 R14: 00000000000058b2 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7e802f1f60 CR3: 000000006be62000 CR4: 00000000003506f0 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:211 [inline] unwind_next_frame+0x216/0x2990 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x290 mm/slub.c:3852 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x723/0xa90 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293