===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.15.122-syzkaller #0 Not tainted ----------------------------------------------------- syz-executor.0/24406 [HC0[0]:SC0[2]:HE1:SE0] is trying to acquire: ffffffff8c9df360 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:206 [inline] ffffffff8c9df360 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 and this task is already holding: ffff88801bc38108 (&sch->q.lock){+.-.}-{2:2}, at: netem_change+0x257/0x20c0 net/sched/sch_netem.c:972 which would create a new lock dependency: (&sch->q.lock){+.-.}-{2:2} -> (fs_reclaim){+.+.}-{0:0} but this new dependency connects a SOFTIRQ-irq-safe lock: (&sch->q.lock){+.-.}-{2:2} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] __dev_xmit_skb net/core/dev.c:3848 [inline] __dev_queue_xmit+0xad6/0x3230 net/core/dev.c:4190 neigh_hh_output include/net/neighbour.h:493 [inline] neigh_output include/net/neighbour.h:507 [inline] ip6_finish_output2+0xea9/0x14f0 net/ipv6/ip6_output.c:126 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0xf5a/0x1560 net/ipv6/ip6_output.c:324 inet6_csk_xmit+0x441/0x6b0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1f36/0x3820 net/ipv4/tcp_output.c:1403 tcp_delack_timer_handler+0x33c/0x790 net/ipv4/tcp_timer.c:318 tcp_delack_timer+0x187/0x2e0 net/ipv4/tcp_timer.c:345 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 preempt_count_sub+0x4b/0x160 kernel/sched/core.c:5518 delay_tsc+0x4b/0xd0 arch/x86/lib/delay.c:77 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:702 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline] process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 to a SOFTIRQ-irq-unsafe lock: (fs_reclaim){+.+.}-{0:0} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __fs_reclaim_acquire mm/page_alloc.c:4547 [inline] fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4561 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x49/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] alloc_workqueue_attrs kernel/workqueue.c:3406 [inline] wq_numa_init+0x122/0x49f kernel/workqueue.c:5997 workqueue_init+0x18/0x5e1 kernel/workqueue.c:6124 kernel_init_freeable+0x40a/0x5c5 init/main.c:1603 kernel_init+0x19/0x290 init/main.c:1510 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); local_irq_disable(); lock(&sch->q.lock); lock(fs_reclaim); lock(&sch->q.lock); *** DEADLOCK *** 2 locks held by syz-executor.0/24406: #0: ffffffff8d9e0588 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9e0588 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5596 #1: ffff88801bc38108 (&sch->q.lock){+.-.}-{2:2}, at: netem_change+0x257/0x20c0 net/sched/sch_netem.c:972 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&sch->q.lock){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] dev_reset_queue+0xc1/0x140 net/sched/sch_generic.c:1245 netdev_for_each_tx_queue include/linux/netdevice.h:2379 [inline] dev_deactivate_many+0x6ad/0xbf0 net/sched/sch_generic.c:1313 dev_deactivate+0x177/0x270 net/sched/sch_generic.c:1336 linkwatch_do_dev+0x104/0x160 net/core/link_watch.c:165 __linkwatch_run_queue+0x4ca/0x7f0 net/core/link_watch.c:213 linkwatch_event+0x48/0x50 net/core/link_watch.c:252 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 IN-SOFTIRQ-W at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] __dev_xmit_skb net/core/dev.c:3848 [inline] __dev_queue_xmit+0xad6/0x3230 net/core/dev.c:4190 neigh_hh_output include/net/neighbour.h:493 [inline] neigh_output include/net/neighbour.h:507 [inline] ip6_finish_output2+0xea9/0x14f0 net/ipv6/ip6_output.c:126 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ip6_xmit+0xf5a/0x1560 net/ipv6/ip6_output.c:324 inet6_csk_xmit+0x441/0x6b0 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1f36/0x3820 net/ipv4/tcp_output.c:1403 tcp_delack_timer_handler+0x33c/0x790 net/ipv4/tcp_timer.c:318 tcp_delack_timer+0x187/0x2e0 net/ipv4/tcp_timer.c:345 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 preempt_count_sub+0x4b/0x160 kernel/sched/core.c:5518 delay_tsc+0x4b/0xd0 arch/x86/lib/delay.c:77 try_check_zero+0x2f2/0x360 kernel/rcu/srcutree.c:702 srcu_advance_state kernel/rcu/srcutree.c:1227 [inline] process_srcu+0x1aa/0xc20 kernel/rcu/srcutree.c:1325 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 INITIAL USE at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] dev_reset_queue+0xc1/0x140 net/sched/sch_generic.c:1245 netdev_for_each_tx_queue include/linux/netdevice.h:2379 [inline] dev_deactivate_many+0x6ad/0xbf0 net/sched/sch_generic.c:1313 dev_deactivate+0x177/0x270 net/sched/sch_generic.c:1336 linkwatch_do_dev+0x104/0x160 net/core/link_watch.c:165 __linkwatch_run_queue+0x4ca/0x7f0 net/core/link_watch.c:213 linkwatch_event+0x48/0x50 net/core/link_watch.c:252 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 } ... key at: [] qdisc_alloc.__key+0x0/0x20 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (fs_reclaim){+.+.}-{0:0} { HARDIRQ-ON-W at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __fs_reclaim_acquire mm/page_alloc.c:4547 [inline] fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4561 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x49/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] alloc_workqueue_attrs kernel/workqueue.c:3406 [inline] wq_numa_init+0x122/0x49f kernel/workqueue.c:5997 workqueue_init+0x18/0x5e1 kernel/workqueue.c:6124 kernel_init_freeable+0x40a/0x5c5 init/main.c:1603 kernel_init+0x19/0x290 init/main.c:1510 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 SOFTIRQ-ON-W at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __fs_reclaim_acquire mm/page_alloc.c:4547 [inline] fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4561 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x49/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] alloc_workqueue_attrs kernel/workqueue.c:3406 [inline] wq_numa_init+0x122/0x49f kernel/workqueue.c:5997 workqueue_init+0x18/0x5e1 kernel/workqueue.c:6124 kernel_init_freeable+0x40a/0x5c5 init/main.c:1603 kernel_init+0x19/0x290 init/main.c:1510 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 INITIAL USE at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __fs_reclaim_acquire mm/page_alloc.c:4547 [inline] fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4561 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x49/0x290 mm/slub.c:3245 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] alloc_workqueue_attrs kernel/workqueue.c:3406 [inline] wq_numa_init+0x122/0x49f kernel/workqueue.c:5997 workqueue_init+0x18/0x5e1 kernel/workqueue.c:6124 kernel_init_freeable+0x40a/0x5c5 init/main.c:1603 kernel_init+0x19/0x290 init/main.c:1510 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 } ... key at: [] __fs_reclaim_map+0x0/0x160 ... acquired at: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __fs_reclaim_acquire mm/page_alloc.c:4547 [inline] fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4561 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] __kmalloc_node+0x71/0x390 mm/slub.c:4451 kmalloc_node include/linux/slab.h:614 [inline] kvmalloc_node+0x80/0x140 mm/util.c:619 kvmalloc include/linux/mm.h:805 [inline] get_dist_table+0x83/0x2c0 net/sched/sch_netem.c:788 netem_change+0xa05/0x20c0 net/sched/sch_netem.c:988 netem_init+0x58/0xb0 net/sched/sch_netem.c:1075 qdisc_create+0x8ae/0x1390 net/sched/sch_api.c:1264 tc_modify_qdisc+0xac5/0x1710 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5599 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2466 __sys_sendmsg net/socket.c:2495 [inline] __do_sys_sendmsg net/socket.c:2504 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2502 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb stack backtrace: CPU: 1 PID: 24406 Comm: syz-executor.0 Not tainted 5.15.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2567 [inline] check_irq_usage kernel/locking/lockdep.c:2806 [inline] check_prev_add kernel/locking/lockdep.c:3057 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x4cfe/0x58b0 kernel/locking/lockdep.c:3787 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __fs_reclaim_acquire mm/page_alloc.c:4547 [inline] fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4561 might_alloc include/linux/sched/mm.h:206 [inline] slab_pre_alloc_hook+0x22/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] __kmalloc_node+0x71/0x390 mm/slub.c:4451 kmalloc_node include/linux/slab.h:614 [inline] kvmalloc_node+0x80/0x140 mm/util.c:619 kvmalloc include/linux/mm.h:805 [inline] get_dist_table+0x83/0x2c0 net/sched/sch_netem.c:788 netem_change+0xa05/0x20c0 net/sched/sch_netem.c:988 netem_init+0x58/0xb0 net/sched/sch_netem.c:1075 qdisc_create+0x8ae/0x1390 net/sched/sch_api.c:1264 tc_modify_qdisc+0xac5/0x1710 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5599 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2466 __sys_sendmsg net/socket.c:2495 [inline] __do_sys_sendmsg net/socket.c:2504 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2502 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f5f0f4a6b29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5f0da070c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f5f0f5c6050 RCX: 00007f5f0f4a6b29 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 00007f5f0f4f247a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f5f0f5c6050 R15: 00007fffb2a3d5c8 BUG: sleeping function called from invalid context at include/linux/sched/mm.h:209 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 24406, name: syz-executor.0 INFO: lockdep is turned off. Preemption disabled at: [<0000000000000000>] 0x0 CPU: 1 PID: 24406 Comm: syz-executor.0 Not tainted 5.15.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 ___might_sleep+0x547/0x6a0 kernel/sched/core.c:9625 might_alloc include/linux/sched/mm.h:209 [inline] slab_pre_alloc_hook+0x44/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] __kmalloc_node+0x71/0x390 mm/slub.c:4451 kmalloc_node include/linux/slab.h:614 [inline] kvmalloc_node+0x80/0x140 mm/util.c:619 kvmalloc include/linux/mm.h:805 [inline] get_dist_table+0x83/0x2c0 net/sched/sch_netem.c:788 netem_change+0xa05/0x20c0 net/sched/sch_netem.c:988 netem_init+0x58/0xb0 net/sched/sch_netem.c:1075 qdisc_create+0x8ae/0x1390 net/sched/sch_api.c:1264 tc_modify_qdisc+0xac5/0x1710 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5599 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2412 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2466 __sys_sendmsg net/socket.c:2495 [inline] __do_sys_sendmsg net/socket.c:2504 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2502 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f5f0f4a6b29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5f0da070c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f5f0f5c6050 RCX: 00007f5f0f4a6b29 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 00007f5f0f4f247a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f5f0f5c6050 R15: 00007fffb2a3d5c8