Extracting prog: 2m30.237623594s Minimizing prog: 8m40.277546334s Simplifying prog options: 0s Extracting C: 50.361815172s Simplifying C: 16m58.182609456s 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}}): socket$kcm-sendmsg$kcm detailed listing: executing program 0: r0 = socket$kcm(0x10, 0x2, 0x0) sendmsg$kcm(r0, &(0x7f0000000600)={0x0, 0x0, &(0x7f0000000300)=[{&(0x7f0000000000)="2e00000010008188e6b62aa73772cc9f1ba1f848430000005e140602000000000e000a0010000000028000001294", 0x2e}], 0x1}, 0x0) program crashed: possible deadlock in team_port_change_check single: successfully extracted reproducer found reproducer with 2 syscalls minimizing guilty program testing program (duration=53.272101472s, {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}}): socket$kcm detailed listing: executing program 0: socket$kcm(0x10, 0x2, 0x0) program did not crash testing program (duration=53.272101472s, {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}}): sendmsg$kcm detailed listing: executing program 0: sendmsg$kcm(0xffffffffffffffff, &(0x7f0000000600)={0x0, 0x0, &(0x7f0000000300)=[{&(0x7f0000000000)="2e00000010008188e6b62aa73772cc9f1ba1f848430000005e140602000000000e000a0010000000028000001294", 0x2e}], 0x1}, 0x0) program did not crash testing program (duration=53.272101472s, {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}}): socket$kcm-sendmsg$kcm detailed listing: executing program 0: r0 = socket$kcm(0x10, 0x2, 0x0) sendmsg$kcm(r0, 0x0, 0x0) program did not crash testing program (duration=53.272101472s, {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}}): socket$kcm-sendmsg$kcm detailed listing: executing program 0: r0 = socket$kcm(0x10, 0x2, 0x0) sendmsg$kcm(r0, &(0x7f0000000600)={0x0, 0x0, 0x0}, 0x0) program did not crash testing program (duration=53.272101472s, {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}}): socket$kcm-sendmsg$kcm detailed listing: executing program 0: r0 = socket$kcm(0x10, 0x2, 0x0) sendmsg$kcm(r0, &(0x7f0000000600)={0x0, 0x0, &(0x7f0000000300)=[{0x0}], 0x1}, 0x0) program did not crash testing program (duration=53.272101472s, {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}}): socket$kcm-sendmsg$kcm detailed listing: executing program 0: r0 = socket$kcm(0x10, 0x2, 0x0) sendmsg$kcm(r0, &(0x7f0000000600)={0x0, 0x0, &(0x7f0000000300)=[{}], 0x1}, 0x0) program did not crash extracting C reproducer testing compiled C program (duration=53.272101472s, {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}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check simplifying C reproducer testing compiled C program (duration=53.272101472s, {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}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false 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}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false 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 LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program did not crash testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:false 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}}): socket$kcm-sendmsg$kcm program did not crash testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:false 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}}): socket$kcm-sendmsg$kcm program did not crash testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:false 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}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false 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}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false 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}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true 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:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true 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:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true 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:true UseTmpDir:false HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true 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:true UseTmpDir:false HandleSegv:false Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true 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:true UseTmpDir:false HandleSegv:false Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check testing compiled C program (duration=53.272101472s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$kcm-sendmsg$kcm program crashed: possible deadlock in team_port_change_check reproducing took 28m59.059641333s repro crashed as (corrupted=false): ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc2-syzkaller-g82303a059aab #0 Not tainted ------------------------------------------------------ kworker/u8:3/54 is trying to acquire lock: ffff888034788e00 (team->team_lock_key){+.+.}-{4:4}, at: team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 but task is already holding lock: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: __linkwatch_run_queue+0x616/0x940 net/core/link_watch.c:243 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&dev_instance_lock_key#19){+.+.}-{4:4}: 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] netdev_lock_ops include/net/netdev_lock.h:42 [inline] dev_set_mtu+0x11c/0x270 net/core/dev_api.c:246 team_port_add drivers/net/team/team_core.c:1215 [inline] team_add_slave+0x83b/0x28b0 drivers/net/team/team_core.c:1989 do_set_master+0x579/0x730 net/core/rtnetlink.c:2946 do_setlink+0xf76/0x4390 net/core/rtnetlink.c:3159 rtnl_changelink net/core/rtnetlink.c:3772 [inline] __rtnl_newlink net/core/rtnetlink.c:3931 [inline] rtnl_newlink+0x17e2/0x1fe0 net/core/rtnetlink.c:4068 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (team->team_lock_key){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __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 team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 team_device_event+0x437/0x5b0 drivers/net/team/team_core.c:2996 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 netif_state_change+0x123/0x1a0 net/core/dev.c:1528 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x63b/0x940 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev_instance_lock_key#19); lock(team->team_lock_key); lock(&dev_instance_lock_key#19); lock(team->team_lock_key); *** DEADLOCK *** 4 locks held by kworker/u8:3/54: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fd488 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 #3: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #3: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #3: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: __linkwatch_run_queue+0x616/0x940 net/core/link_watch.c:243 stack backtrace: CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:3 Not tainted 6.15.0-rc2-syzkaller-g82303a059aab #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound linkwatch_event Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __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 team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 team_device_event+0x437/0x5b0 drivers/net/team/team_core.c:2996 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 netif_state_change+0x123/0x1a0 net/core/dev.c:1528 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x63b/0x940 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 final repro crashed as (corrupted=false): ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc2-syzkaller-g82303a059aab #0 Not tainted ------------------------------------------------------ kworker/u8:3/54 is trying to acquire lock: ffff888034788e00 (team->team_lock_key){+.+.}-{4:4}, at: team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 but task is already holding lock: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: __linkwatch_run_queue+0x616/0x940 net/core/link_watch.c:243 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&dev_instance_lock_key#19){+.+.}-{4:4}: 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] netdev_lock_ops include/net/netdev_lock.h:42 [inline] dev_set_mtu+0x11c/0x270 net/core/dev_api.c:246 team_port_add drivers/net/team/team_core.c:1215 [inline] team_add_slave+0x83b/0x28b0 drivers/net/team/team_core.c:1989 do_set_master+0x579/0x730 net/core/rtnetlink.c:2946 do_setlink+0xf76/0x4390 net/core/rtnetlink.c:3159 rtnl_changelink net/core/rtnetlink.c:3772 [inline] __rtnl_newlink net/core/rtnetlink.c:3931 [inline] rtnl_newlink+0x17e2/0x1fe0 net/core/rtnetlink.c:4068 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (team->team_lock_key){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __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 team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 team_device_event+0x437/0x5b0 drivers/net/team/team_core.c:2996 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 netif_state_change+0x123/0x1a0 net/core/dev.c:1528 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x63b/0x940 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev_instance_lock_key#19); lock(team->team_lock_key); lock(&dev_instance_lock_key#19); lock(team->team_lock_key); *** DEADLOCK *** 4 locks held by kworker/u8:3/54: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fd488 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 #3: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #3: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #3: ffff88807ac0cd30 (&dev_instance_lock_key#19){+.+.}-{4:4}, at: __linkwatch_run_queue+0x616/0x940 net/core/link_watch.c:243 stack backtrace: CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:3 Not tainted 6.15.0-rc2-syzkaller-g82303a059aab #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound linkwatch_event Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909 __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 team_port_change_check+0x51/0x1e0 drivers/net/team/team_core.c:2966 team_device_event+0x437/0x5b0 drivers/net/team/team_core.c:2996 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 netif_state_change+0x123/0x1a0 net/core/dev.c:1528 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:186 __linkwatch_run_queue+0x63b/0x940 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245