Extracting prog: 5m16.231828893s Minimizing prog: 49m1.224670258s Simplifying prog options: 0s Extracting C: 3m10.249074828s Simplifying C: 23m54.367975656s 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$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program crashed: INFO: task hung in vfs_coredump single: successfully extracted reproducer found reproducer with 4 syscalls minimizing guilty program testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, 0x0) mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, 0x0, &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', 0x0, 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program did not crash testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:4 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, 0x0) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) 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$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump simplifying C reproducer testing compiled C 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$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON 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: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$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON program crashed: INFO: task hung in vfs_coredump testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program crashed: INFO: task hung in vfs_coredump validation run: crashed=true testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program crashed: INFO: task hung in vfs_coredump validation run: crashed=true testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 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 CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$tty1-syz_open_procfs-mount$9p_fd-prctl$PR_SET_SYSCALL_USER_DISPATCH_ON detailed listing: executing program 0: syz_open_dev$tty1(0xc, 0x4, 0x2) r0 = syz_open_procfs(0x0, &(0x7f00000000c0)='fd/3\x00') mount$9p_fd(0x0, &(0x7f0000000300)='.\x00', &(0x7f0000000080), 0x40, &(0x7f0000000180)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r0}}) prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x8, 0x8, 0x0) program crashed: INFO: task hung in vfs_coredump validation run: crashed=true reproducing took 1h31m2.906630832s repro crashed as (corrupted=false): INFO: task syz.0.17:6035 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:25288 pid:6035 tgid:6030 ppid:5953 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1539/0x5080 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3c0/0x690 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x9c7/0x4280 fs/coredump.c:1197 get_signal+0x1107/0x1330 kernel/signal.c:3019 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb10b9aeb9 RSP: 002b:00007feb119e60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007feb10e16098 RCX: 00007feb10b9aeb9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007feb10e1609c RBP: 00007feb10e16090 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb10e16128 R14: 00007fff989bce00 R15: 00007fff989bcee8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e9601a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e9601a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e9601a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5578: #0: ffff88803738c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by syz-executor/6277: ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 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: 6277 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:lookup_object lib/debugobjects.c:-1 [inline] RIP: 0010:debug_object_deactivate+0x8b/0x3a0 lib/debugobjects.c:875 Code: 9a 48 89 7c 24 18 e8 74 66 f4 06 48 89 44 24 10 4c 89 e8 48 c1 e8 03 42 80 3c 30 00 74 08 4c 89 ef e8 89 07 75 fd 4d 8b 6d 00 44 24 0c 00 00 00 00 41 bc 00 00 00 00 4d 85 ed 74 49 45 31 e4 RSP: 0018:ffffc90000007d00 EFLAGS: 00000046 RAX: 1ffffffff34eb767 RBX: ffff8880b8426140 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007c60 RBP: ffffc90000007f10 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f8c R12: dffffc0000000000 R13: ffff88803130d310 R14: dffffc0000000000 R15: ffffffff9a829040 FS: 000055557777e500(0000) GS:ffff888125052000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f090dbe5ba0 CR3: 000000007bf3e000 CR4: 00000000003526f0 Call Trace: debug_timer_deactivate kernel/time/timer.c:798 [inline] debug_deactivate kernel/time/timer.c:842 [inline] detach_timer+0x33/0x2b0 kernel/time/timer.c:889 expire_timers kernel/time/timer.c:1782 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x5d3/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2427 Code: 0f 84 44 ff ff ff e8 f2 f3 20 00 fb eb 44 e8 ea f3 20 00 e8 55 1a 07 0a 4d 85 f6 74 94 e8 db f3 20 00 fb 48 c7 c7 a0 25 95 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 2b 1b RSP: 0018:ffffc900039ae9e0 EFLAGS: 00000293 RAX: ffffffff81a445a5 RBX: ffffffff81a4441f RCX: ffff8880314ebc80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e9525a0 RBP: ffffc900039aea90 R08: ffffffff903284b7 R09: 1ffffffff2065096 R10: dffffc0000000000 R11: fffffbfff2065097 R12: 0000000000000000 R13: 0000000000000029 R14: 0000000000000200 R15: 1ffff92000735d40 _printk+0xdd/0x130 kernel/printk/printk.c:2453 netdev_info+0x11e/0x180 net/core/dev.c:12992 netif_set_allmulti+0x1a8/0x360 net/core/dev.c:9628 dev_set_allmulti+0x12b/0x260 net/core/dev_api.c:313 br_add_if+0x308/0xeb0 net/bridge/br_if.c:592 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 do_setlink+0x1018/0x4590 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ff/0x590 net/socket.c:2221 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f090db5b78e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffea08f97e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055557777e500 RCX: 00007f090db5b78e RDX: 0000000000000028 RSI: 00007f090e944670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffea08f9864 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f090e944670 R15: 0000000000000000 final repro crashed as (corrupted=false): INFO: task syz.0.17:6035 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:25288 pid:6035 tgid:6030 ppid:5953 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1539/0x5080 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3c0/0x690 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x9c7/0x4280 fs/coredump.c:1197 get_signal+0x1107/0x1330 kernel/signal.c:3019 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb10b9aeb9 RSP: 002b:00007feb119e60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007feb10e16098 RCX: 00007feb10b9aeb9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007feb10e1609c RBP: 00007feb10e16090 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb10e16128 R14: 00007fff989bce00 R15: 00007fff989bcee8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e9601a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e9601a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e9601a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5578: #0: ffff88803738c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by syz-executor/6277: ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51b/0xa40 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: 6277 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:lookup_object lib/debugobjects.c:-1 [inline] RIP: 0010:debug_object_deactivate+0x8b/0x3a0 lib/debugobjects.c:875 Code: 9a 48 89 7c 24 18 e8 74 66 f4 06 48 89 44 24 10 4c 89 e8 48 c1 e8 03 42 80 3c 30 00 74 08 4c 89 ef e8 89 07 75 fd 4d 8b 6d 00 44 24 0c 00 00 00 00 41 bc 00 00 00 00 4d 85 ed 74 49 45 31 e4 RSP: 0018:ffffc90000007d00 EFLAGS: 00000046 RAX: 1ffffffff34eb767 RBX: ffff8880b8426140 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007c60 RBP: ffffc90000007f10 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f8c R12: dffffc0000000000 R13: ffff88803130d310 R14: dffffc0000000000 R15: ffffffff9a829040 FS: 000055557777e500(0000) GS:ffff888125052000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f090dbe5ba0 CR3: 000000007bf3e000 CR4: 00000000003526f0 Call Trace: debug_timer_deactivate kernel/time/timer.c:798 [inline] debug_deactivate kernel/time/timer.c:842 [inline] detach_timer+0x33/0x2b0 kernel/time/timer.c:889 expire_timers kernel/time/timer.c:1782 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x5d3/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2427 Code: 0f 84 44 ff ff ff e8 f2 f3 20 00 fb eb 44 e8 ea f3 20 00 e8 55 1a 07 0a 4d 85 f6 74 94 e8 db f3 20 00 fb 48 c7 c7 a0 25 95 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 2b 1b RSP: 0018:ffffc900039ae9e0 EFLAGS: 00000293 RAX: ffffffff81a445a5 RBX: ffffffff81a4441f RCX: ffff8880314ebc80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e9525a0 RBP: ffffc900039aea90 R08: ffffffff903284b7 R09: 1ffffffff2065096 R10: dffffc0000000000 R11: fffffbfff2065097 R12: 0000000000000000 R13: 0000000000000029 R14: 0000000000000200 R15: 1ffff92000735d40 _printk+0xdd/0x130 kernel/printk/printk.c:2453 netdev_info+0x11e/0x180 net/core/dev.c:12992 netif_set_allmulti+0x1a8/0x360 net/core/dev.c:9628 dev_set_allmulti+0x12b/0x260 net/core/dev_api.c:313 br_add_if+0x308/0xeb0 net/bridge/br_if.c:592 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 do_setlink+0x1018/0x4590 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ff/0x590 net/socket.c:2221 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f090db5b78e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffea08f97e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055557777e500 RCX: 00007f090db5b78e RDX: 0000000000000028 RSI: 00007f090e944670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffea08f9864 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f090e944670 R15: 0000000000000000