============================================ WARNING: possible recursive locking detected 6.1.82-syzkaller #0 Not tainted -------------------------------------------- syz-executor.0/32593 is trying to acquire lock: ffff0001b437d758 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x108/0x214 kernel/time/timer.c:999 but task is already holding lock: ffff0001b435c758 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x108/0x214 kernel/time/timer.c:999 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&base->lock); lock(&base->lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz-executor.0/32593: #0: ffff0001a1a42e30 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1745 [inline] #0: ffff0001a1a42e30 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_sendmsg+0x8fc/0x2844 net/sctp/socket.c:1968 #1: ffff0001b435c758 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x108/0x214 kernel/time/timer.c:999 stack backtrace: CPU: 0 PID: 32593 Comm: syz-executor.0 Not tainted 6.1.82-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 __lock_acquire+0x6310/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x6c/0xb4 kernel/locking/spinlock.c:162 lock_timer_base+0x108/0x214 kernel/time/timer.c:999 __mod_timer+0x1b4/0xd30 kernel/time/timer.c:1072 add_timer+0x6c/0x88 kernel/time/timer.c:1197 __queue_delayed_work kernel/workqueue.c:1679 [inline] queue_delayed_work_on+0x1f0/0x320 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_work include/linux/workqueue.h:679 [inline] __debug_check_no_obj_freed lib/debugobjects.c:1001 [inline] debug_check_no_obj_freed+0xc8/0x478 lib/debugobjects.c:1008 free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0x450/0x1070 mm/page_alloc.c:3358 free_unref_page+0x80/0x420 mm/page_alloc.c:3453 free_the_page mm/page_alloc.c:750 [inline] __free_pages+0x1a0/0x1cc mm/page_alloc.c:5634 free_pages+0xa0/0xb8 mm/page_alloc.c:5645 __stack_depot_save+0x3a0/0x4dc lib/stackdepot.c:506 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x64/0x80 mm/kasan/common.c:52 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x458 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x230/0x37c mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] fill_pool lib/debugobjects.c:168 [inline] debug_objects_fill_pool+0x5e0/0x7d4 lib/debugobjects.c:606 debug_object_activate+0x48/0x4b4 lib/debugobjects.c:693 debug_timer_activate kernel/time/timer.c:782 [inline] __mod_timer+0x830/0xd30 kernel/time/timer.c:1103 mod_timer+0x2c/0x3c kernel/time/timer.c:1161 sctp_transport_reset_hb_timer+0xfc/0x158 net/sctp/transport.c:199 sctp_cmd_hb_timers_start net/sctp/sm_sideeffect.c:725 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1671 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x17c4/0x4e80 net/sctp/sm_sideeffect.c:1170 sctp_assoc_bh_rcv+0x380/0x710 net/sctp/associola.c:1053 sctp_inq_push+0x19c/0x1c0 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x150/0x354 net/sctp/input.c:346 sk_backlog_rcv include/net/sock.h:1117 [inline] __release_sock+0x1a8/0x408 net/core/sock.c:2935 release_sock+0x68/0x1cc net/core/sock.c:3499 sctp_wait_for_connect+0x2f0/0x564 net/sctp/socket.c:9336 sctp_sendmsg_to_asoc+0xff0/0x13b8 net/sctp/socket.c:1883 sctp_sendmsg+0x196c/0x2844 net/sctp/socket.c:2029 inet_sendmsg+0x15c/0x290 net/ipv4/af_inet.c:839 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x3b8/0x508 net/socket.c:2148 __do_sys_sendto net/socket.c:2160 [inline] __se_sys_sendto net/socket.c:2156 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2156 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585