====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/27365 is trying to acquire lock: ffffffff8c7d6b20 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x30 mm/page_alloc.c:4210 but task is already holding lock: ffff8880b9d4d0c8 (lock#2){-.-.}-{2:2}, at: local_lock_acquire+0x7/0x130 include/linux/local_lock_internal.h:41 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (lock#2){-.-.}-{2:2}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 local_lock_acquire+0x23/0x130 include/linux/local_lock_internal.h:42 free_unref_page+0x242/0x550 mm/page_alloc.c:3427 mm_free_pgd kernel/fork.c:636 [inline] __mmdrop+0xae/0x3f0 kernel/fork.c:687 mmdrop include/linux/sched/mm.h:49 [inline] finish_task_switch+0x221/0x630 kernel/sched/core.c:4582 context_switch kernel/sched/core.c:4686 [inline] __schedule+0xc0f/0x11f0 kernel/sched/core.c:5940 preempt_schedule_notrace+0x12c/0x170 kernel/sched/core.c:6179 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:36 rcu_read_unlock_sched_notrace include/linux/rcupdate.h:809 [inline] trace_lock_release+0xa1/0x150 include/trace/events/lock.h:58 lock_release+0x81/0x7b0 kernel/locking/lockdep.c:5636 might_alloc include/linux/sched/mm.h:199 [inline] slab_pre_alloc_hook mm/slab.h:485 [inline] slab_alloc_node mm/slub.c:2902 [inline] __kmalloc_node_track_caller+0x64/0x410 mm/slub.c:4681 kmalloc_reserve net/core/skbuff.c:355 [inline] __alloc_skb+0x127/0x580 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1112 [inline] nlmsg_new include/net/netlink.h:953 [inline] rtmsg_fib+0x11d/0x580 net/ipv4/fib_semantics.c:512 fib_table_insert+0x110b/0x2460 net/ipv4/fib_trie.c:1389 fib_magic+0x447/0x610 net/ipv4/fib_frontend.c:1087 fib_netdev_event+0x718/0x860 net/ipv4/fib_frontend.c:1466 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xe7/0x170 kernel/notifier.c:410 __dev_notify_flags+0x306/0x5d0 net/core/dev.c:2122 dev_change_flags+0xe3/0x190 net/core/dev.c:8870 do_setlink+0xcbd/0x3f70 net/core/rtnetlink.c:2721 __rtnl_newlink net/core/rtnetlink.c:3393 [inline] rtnl_newlink+0x16e4/0x1cd0 net/core/rtnetlink.c:3508 rtnetlink_rcv_msg+0x91c/0xe50 net/core/rtnetlink.c:5574 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2504 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x9e7/0xe00 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:702 [inline] sock_sendmsg net/socket.c:722 [inline] __sys_sendto+0x541/0x720 net/socket.c:2012 __do_sys_sendto net/socket.c:2024 [inline] __se_sys_sendto net/socket.c:2020 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2020 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+0x44/0xae -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add+0x4f9/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4552 fs_reclaim_acquire+0x59/0xf0 mm/page_alloc.c:4566 prepare_alloc_pages+0x151/0x5a0 mm/page_alloc.c:5164 __alloc_pages+0x14d/0x5f0 mm/page_alloc.c:5363 stack_depot_save+0x361/0x490 lib/stackdepot.c:303 save_stack+0xf9/0x1f0 mm/page_owner.c:120 __set_page_owner+0x42/0x2f0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x9f2/0x1090 mm/page_alloc.c:5301 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x3ad/0x7f0 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vmalloc+0x75/0x80 mm/vmalloc.c:3048 htable_create net/netfilter/xt_hashlimit.c:298 [inline] hashlimit_mt_check_common+0x897/0x1300 net/netfilter/xt_hashlimit.c:898 hashlimit_mt_check_v1+0x2d2/0x4e0 net/netfilter/xt_hashlimit.c:924 xt_check_match+0x336/0xcf0 net/netfilter/x_tables.c:509 check_match net/ipv6/netfilter/ip6_tables.c:489 [inline] find_check_match net/ipv6/netfilter/ip6_tables.c:506 [inline] find_check_entry net/ipv6/netfilter/ip6_tables.c:557 [inline] translate_table+0x16cd/0x2410 net/ipv6/netfilter/ip6_tables.c:734 do_replace net/ipv6/netfilter/ip6_tables.c:1152 [inline] do_ip6t_set_ctl+0x2c31/0x3d90 net/ipv6/netfilter/ip6_tables.c:1638 nf_setsockopt+0x29f/0x2d0 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0x4685/0x5770 net/ipv6/ipv6_sockglue.c:1008 rawv6_setsockopt+0x2b9/0x6e0 net/ipv6/raw.c:1081 __sys_setsockopt+0x552/0x980 net/socket.c:2152 __do_sys_setsockopt net/socket.c:2163 [inline] __se_sys_setsockopt net/socket.c:2160 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2160 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+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#2); lock(fs_reclaim); lock(lock#2); lock(fs_reclaim); *** DEADLOCK *** 2 locks held by syz-executor.0/27365: #0: ffffffff8d7db388 (hashlimit_mutex){+.+.}-{3:3}, at: hashlimit_mt_check_common+0x656/0x1300 net/netfilter/xt_hashlimit.c:895 #1: ffff8880b9d4d0c8 (lock#2){-.-.}-{2:2}, at: local_lock_acquire+0x7/0x130 include/linux/local_lock_internal.h:41 stack backtrace: CPU: 1 PID: 27365 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 print_circular_bug+0xb17/0xdc0 kernel/locking/lockdep.c:2009 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add+0x4f9/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4552 fs_reclaim_acquire+0x59/0xf0 mm/page_alloc.c:4566 prepare_alloc_pages+0x151/0x5a0 mm/page_alloc.c:5164 __alloc_pages+0x14d/0x5f0 mm/page_alloc.c:5363 stack_depot_save+0x361/0x490 lib/stackdepot.c:303 save_stack+0xf9/0x1f0 mm/page_owner.c:120 __set_page_owner+0x42/0x2f0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x9f2/0x1090 mm/page_alloc.c:5301 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x3ad/0x7f0 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vmalloc+0x75/0x80 mm/vmalloc.c:3048 htable_create net/netfilter/xt_hashlimit.c:298 [inline] hashlimit_mt_check_common+0x897/0x1300 net/netfilter/xt_hashlimit.c:898 hashlimit_mt_check_v1+0x2d2/0x4e0 net/netfilter/xt_hashlimit.c:924 xt_check_match+0x336/0xcf0 net/netfilter/x_tables.c:509 check_match net/ipv6/netfilter/ip6_tables.c:489 [inline] find_check_match net/ipv6/netfilter/ip6_tables.c:506 [inline] find_check_entry net/ipv6/netfilter/ip6_tables.c:557 [inline] translate_table+0x16cd/0x2410 net/ipv6/netfilter/ip6_tables.c:734 do_replace net/ipv6/netfilter/ip6_tables.c:1152 [inline] do_ip6t_set_ctl+0x2c31/0x3d90 net/ipv6/netfilter/ip6_tables.c:1638 nf_setsockopt+0x29f/0x2d0 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0x4685/0x5770 net/ipv6/ipv6_sockglue.c:1008 rawv6_setsockopt+0x2b9/0x6e0 net/ipv6/raw.c:1081 __sys_setsockopt+0x552/0x980 net/socket.c:2152 __do_sys_setsockopt net/socket.c:2163 [inline] __se_sys_setsockopt net/socket.c:2160 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2160 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+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2063526188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000e00 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcc846248f R14: 00007f2063526300 R15: 0000000000022000 BUG: sleeping function called from invalid context at mm/page_alloc.c:5167 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 27365, name: syz-executor.0 INFO: lockdep is turned off. irq event stamp: 426 hardirqs last enabled at (425): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (425): [] _raw_spin_unlock_irqrestore+0x8b/0x120 kernel/locking/spinlock.c:191 hardirqs last disabled at (426): [] __alloc_pages_bulk+0x801/0x1090 mm/page_alloc.c:5279 softirqs last enabled at (384): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last enabled at (384): [] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 softirqs last disabled at (365): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last disabled at (365): [] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 CPU: 1 PID: 27365 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 ___might_sleep+0x4e5/0x6b0 kernel/sched/core.c:9154 prepare_alloc_pages+0x1c0/0x5a0 mm/page_alloc.c:5167 __alloc_pages+0x14d/0x5f0 mm/page_alloc.c:5363 stack_depot_save+0x361/0x490 lib/stackdepot.c:303 save_stack+0xf9/0x1f0 mm/page_owner.c:120 __set_page_owner+0x42/0x2f0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x9f2/0x1090 mm/page_alloc.c:5301 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x3ad/0x7f0 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vmalloc+0x75/0x80 mm/vmalloc.c:3048 htable_create net/netfilter/xt_hashlimit.c:298 [inline] hashlimit_mt_check_common+0x897/0x1300 net/netfilter/xt_hashlimit.c:898 hashlimit_mt_check_v1+0x2d2/0x4e0 net/netfilter/xt_hashlimit.c:924 xt_check_match+0x336/0xcf0 net/netfilter/x_tables.c:509 check_match net/ipv6/netfilter/ip6_tables.c:489 [inline] find_check_match net/ipv6/netfilter/ip6_tables.c:506 [inline] find_check_entry net/ipv6/netfilter/ip6_tables.c:557 [inline] translate_table+0x16cd/0x2410 net/ipv6/netfilter/ip6_tables.c:734 do_replace net/ipv6/netfilter/ip6_tables.c:1152 [inline] do_ip6t_set_ctl+0x2c31/0x3d90 net/ipv6/netfilter/ip6_tables.c:1638 nf_setsockopt+0x29f/0x2d0 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0x4685/0x5770 net/ipv6/ipv6_sockglue.c:1008 rawv6_setsockopt+0x2b9/0x6e0 net/ipv6/raw.c:1081 __sys_setsockopt+0x552/0x980 net/socket.c:2152 __do_sys_setsockopt net/socket.c:2163 [inline] __se_sys_setsockopt net/socket.c:2160 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2160 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+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2063526188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000e00 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcc846248f R14: 00007f2063526300 R15: 0000000000022000 x_tables: ip6_tables: CLASSIFY target: used from hooks PREROUTING, but only usable from FORWARD/OUTPUT/POSTROUTING