Extracting prog: 1m11.331119454s Minimizing prog: 8m11.581781073s Simplifying prog options: 3m37.800868649s Extracting C: 1m6.672881391s Simplifying C: 0s extracting reproducer from 1 programs testing a last program of every proc single: executing 1 programs separately with timeout 30s testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_TASK_FD_QUERY-openat$cgroup_root-bpf$PROG_LOAD-bpf$BPF_PROG_DETACH detailed listing: executing program 0: bpf$BPF_TASK_FD_QUERY(0x14, &(0x7f0000000240)={0x0, 0xffffffffffffffff, 0x0, 0x7, &(0x7f0000000000)='cgroup\x00'}, 0x30) r0 = openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0) r1 = bpf$PROG_LOAD(0x5, &(0x7f0000000080)={0x9, 0x4, 0x0, &(0x7f0000000100)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @cgroup_sock, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0, 0x0, 0x0, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94) bpf$BPF_PROG_DETACH(0x8, &(0x7f0000000180)=ANY=[@ANYRES32=r0, @ANYRES32=r1, @ANYBLOB="0200"], 0x10) program crashed: possible deadlock in lapbeth_device_event single: successfully extracted reproducer found reproducer with 4 syscalls minimizing guilty program testing program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_TASK_FD_QUERY-openat$cgroup_root-bpf$PROG_LOAD detailed listing: executing program 0: bpf$BPF_TASK_FD_QUERY(0x14, &(0x7f0000000240)={0x0, 0xffffffffffffffff, 0x0, 0x7, &(0x7f0000000000)='cgroup\x00'}, 0x30) openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0) bpf$PROG_LOAD(0x5, &(0x7f0000000080)={0x9, 0x4, 0x0, &(0x7f0000000100)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @cgroup_sock, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0, 0x0, 0x0, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94) program crashed: possible deadlock in lapbeth_device_event testing program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_TASK_FD_QUERY-openat$cgroup_root detailed listing: executing program 0: bpf$BPF_TASK_FD_QUERY(0x14, &(0x7f0000000240)={0x0, 0xffffffffffffffff, 0x0, 0x7, &(0x7f0000000000)='cgroup\x00'}, 0x30) openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0) program did not crash testing program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_TASK_FD_QUERY-bpf$PROG_LOAD detailed listing: executing program 0: bpf$BPF_TASK_FD_QUERY(0x14, &(0x7f0000000240)={0x0, 0xffffffffffffffff, 0x0, 0x7, &(0x7f0000000000)='cgroup\x00'}, 0x30) bpf$PROG_LOAD(0x5, &(0x7f0000000080)={0x9, 0x4, 0x0, &(0x7f0000000100)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @cgroup_sock, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0, 0x0, 0x0, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94) program did not crash testing program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD detailed listing: executing program 0: openat$cgroup_root(0xffffffffffffff9c, &(0x7f0000000000), 0x200002, 0x0) bpf$PROG_LOAD(0x5, &(0x7f0000000080)={0x9, 0x4, 0x0, &(0x7f0000000100)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @cgroup_sock, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0, 0x0, 0x0, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94) program crashed: possible deadlock in lapbeth_device_event testing program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD detailed listing: executing program 0: openat$cgroup_root(0xffffffffffffff9c, 0x0, 0x200002, 0x0) bpf$PROG_LOAD(0x5, &(0x7f0000000080)={0x9, 0x4, 0x0, &(0x7f0000000100)='GPL\x00', 0x0, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @cgroup_sock, 0xffffffffffffffff, 0x8, 0x0, 0x0, 0x10, 0x0, 0x0, 0x0, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94) program crashed: possible deadlock in lapbeth_device_event testing program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD detailed listing: executing program 0: openat$cgroup_root(0xffffffffffffff9c, 0x0, 0x200002, 0x0) bpf$PROG_LOAD(0x5, 0x0, 0x0) program crashed: possible deadlock in lapbeth_device_event extracting C reproducer testing compiled C program (duration=53.214715447s, {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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD program did not crash simplifying guilty program options testing program (duration=53.214715447s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD detailed listing: executing program 0: openat$cgroup_root(0xffffffffffffff9c, 0x0, 0x200002, 0x0) bpf$PROG_LOAD(0x5, 0x0, 0x0) program did not crash testing program (duration=53.214715447s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD detailed listing: executing program 0: openat$cgroup_root(0xffffffffffffff9c, 0x0, 0x200002, 0x0) bpf$PROG_LOAD(0x5, 0x0, 0x0) program crashed: possible deadlock in lapbeth_device_event extracting C reproducer testing compiled C program (duration=53.214715447s, {Threaded:true Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): openat$cgroup_root-bpf$PROG_LOAD program did not crash reproducing took 14m48.277298208s repro crashed as (corrupted=false): ============================================ WARNING: possible recursive locking detected 6.14.0-syzkaller-g25601e85441d #0 Not tainted -------------------------------------------- dhcpcd/5504 is trying to acquire lock: ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: netif_napi_add_weight include/linux/netdevice.h:2783 [inline] ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: lapbeth_new_device drivers/net/wan/lapbether.c:415 [inline] ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: lapbeth_device_event+0x766/0xa20 drivers/net/wan/lapbether.c:460 but task is already holding lock: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: dev_change_flags+0x120/0x270 net/core/dev_api.c:67 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev->lock); lock(&dev->lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by dhcpcd/5504: #0: ffffffff900fb888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fb888 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x34e/0x1d80 net/ipv4/devinet.c:1121 #1: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #1: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: dev_change_flags+0x120/0x270 net/core/dev_api.c:67 stack backtrace: CPU: 1 UID: 0 PID: 5504 Comm: dhcpcd Not tainted 6.14.0-syzkaller-g25601e85441d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x2be/0x2d0 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain+0x928/0x24e0 kernel/locking/lockdep.c:3896 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 netdev_lock include/linux/netdevice.h:2751 [inline] netif_napi_add_weight include/linux/netdevice.h:2783 [inline] lapbeth_new_device drivers/net/wan/lapbether.c:415 [inline] lapbeth_device_event+0x766/0xa20 drivers/net/wan/lapbether.c:460 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 __dev_notify_flags+0x209/0x410 net/core/dev.c:-1 netif_change_flags+0xf0/0x1a0 net/core/dev.c:9438 dev_change_flags+0x146/0x270 net/core/dev_api.c:68 devinet_ioctl+0xea4/0x1d80 net/ipv4/devinet.c:1200 inet_ioctl+0x3d9/0x4f0 net/ipv4/af_inet.c:1001 sock_do_ioctl+0x15a/0x490 net/socket.c:1190 sock_ioctl+0x644/0x900 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f54b0c59d49 Code: 5c c3 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 76 10 48 8b 15 ae 60 0d 00 f7 d8 41 83 c8 RSP: 002b:00007fff772bd8f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f54b0b8b6c0 RCX: 00007f54b0c59d49 RDX: 00007fff772cdae8 RSI: 0000000000008914 RDI: 0000000000000008 RBP: 00007fff772ddca8 R08: 00007fff772cdaa8 R09: 00007fff772cda58 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff772cdae8 R14: 0000000000000028 R15: 0000000000008914 final repro crashed as (corrupted=false): ============================================ WARNING: possible recursive locking detected 6.14.0-syzkaller-g25601e85441d #0 Not tainted -------------------------------------------- dhcpcd/5504 is trying to acquire lock: ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: netif_napi_add_weight include/linux/netdevice.h:2783 [inline] ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: lapbeth_new_device drivers/net/wan/lapbether.c:415 [inline] ffff888065764d30 (&dev->lock){+.+.}-{4:4}, at: lapbeth_device_event+0x766/0xa20 drivers/net/wan/lapbether.c:460 but task is already holding lock: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: dev_change_flags+0x120/0x270 net/core/dev_api.c:67 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev->lock); lock(&dev->lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by dhcpcd/5504: #0: ffffffff900fb888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fb888 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x34e/0x1d80 net/ipv4/devinet.c:1121 #1: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #1: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888028d38d30 (&dev->lock){+.+.}-{4:4}, at: dev_change_flags+0x120/0x270 net/core/dev_api.c:67 stack backtrace: CPU: 1 UID: 0 PID: 5504 Comm: dhcpcd Not tainted 6.14.0-syzkaller-g25601e85441d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x2be/0x2d0 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain+0x928/0x24e0 kernel/locking/lockdep.c:3896 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746 netdev_lock include/linux/netdevice.h:2751 [inline] netif_napi_add_weight include/linux/netdevice.h:2783 [inline] lapbeth_new_device drivers/net/wan/lapbether.c:415 [inline] lapbeth_device_event+0x766/0xa20 drivers/net/wan/lapbether.c:460 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 __dev_notify_flags+0x209/0x410 net/core/dev.c:-1 netif_change_flags+0xf0/0x1a0 net/core/dev.c:9438 dev_change_flags+0x146/0x270 net/core/dev_api.c:68 devinet_ioctl+0xea4/0x1d80 net/ipv4/devinet.c:1200 inet_ioctl+0x3d9/0x4f0 net/ipv4/af_inet.c:1001 sock_do_ioctl+0x15a/0x490 net/socket.c:1190 sock_ioctl+0x644/0x900 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f54b0c59d49 Code: 5c c3 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 76 10 48 8b 15 ae 60 0d 00 f7 d8 41 83 c8 RSP: 002b:00007fff772bd8f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f54b0b8b6c0 RCX: 00007f54b0c59d49 RDX: 00007fff772cdae8 RSI: 0000000000008914 RDI: 0000000000000008 RBP: 00007fff772ddca8 R08: 00007fff772cdaa8 R09: 00007fff772cda58 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff772cdae8 R14: 0000000000000028 R15: 0000000000008914