============================================ WARNING: possible recursive locking detected 6.1.85-syzkaller #0 Not tainted -------------------------------------------- syz-executor.2/7205 is trying to acquire lock: ffff0000ccc8a218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff0000ccc8a218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3884 [inline] ffff0000ccc8a218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1e3c/0x38d8 net/core/dev.c:4259 but task is already holding lock: ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline] ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline] ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x10b4/0x38d8 net/core/dev.c:4259 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); *** DEADLOCK *** May be due to missing lock nesting notation 13 locks held by syz-executor.2/7205: #0: ffff0000c49f20e0 (&type->s_umount_key#62){+.+.}-{3:3}, at: deactivate_super+0xe8/0x110 fs/super.c:362 #1: ffff0000ed629140 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_issue_checkpoint+0x274/0x3b0 #2: ffff0000ed628318 (&sbi->cp_global_sem){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2176 [inline] #2: ffff0000ed628318 (&sbi->cp_global_sem){+.+.}-{3:3}, at: f2fs_write_checkpoint+0x3f0/0x17a0 fs/f2fs/checkpoint.c:1645 #3: ffff0000ed6283b0 (&sbi->cp_rwsem){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2176 [inline] #3: ffff0000ed6283b0 (&sbi->cp_rwsem){++++}-{3:3}, at: f2fs_lock_all fs/f2fs/f2fs.h:2228 [inline] #3: ffff0000ed6283b0 (&sbi->cp_rwsem){++++}-{3:3}, at: block_operations fs/f2fs/checkpoint.c:1224 [inline] #3: ffff0000ed6283b0 (&sbi->cp_rwsem){++++}-{3:3}, at: f2fs_write_checkpoint+0x5c0/0x17a0 fs/f2fs/checkpoint.c:1658 #4: ffff0000ed628448 (&sbi->node_write){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2176 [inline] #4: ffff0000ed628448 (&sbi->node_write){++++}-{3:3}, at: block_operations fs/f2fs/checkpoint.c:1272 [inline] #4: ffff0000ed628448 (&sbi->node_write){++++}-{3:3}, at: f2fs_write_checkpoint+0xadc/0x17a0 fs/f2fs/checkpoint.c:1658 #5: ffff800015a14ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349 #6: ffff800008007c80 ((&ndev->rs_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline] #6: ffff800008007c80 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd0/0xa1c kernel/time/timer.c:1494 #7: ffff800015a14ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 #8: ffff800015a14ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 #9: ffff800015a14d00 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:349 #10: ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] #10: ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline] #10: ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline] #10: ffff0000d84aa258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+.-.}-{2:2}, at: __dev_queue_xmit+0x10b4/0x38d8 net/core/dev.c:4259 #11: ffff800015a14ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 #12: ffff800015a14d00 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:349 stack backtrace: CPU: 0 PID: 7205 Comm: syz-executor.2 Not tainted 6.1.85-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 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/0x5c 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 include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x54/0x6c kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __dev_xmit_skb net/core/dev.c:3884 [inline] __dev_queue_xmit+0x1e3c/0x38d8 net/core/dev.c:4259 dev_queue_xmit include/linux/netdevice.h:3021 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0xc58/0x1198 net/ipv4/ip_output.c:228 __ip_finish_output+0x1b0/0x458 ip_finish_output+0x40/0x268 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_output+0x330/0x49c net/ipv4/ip_output.c:430 dst_output include/net/dst.h:444 [inline] ip_local_out+0x120/0x160 net/ipv4/ip_output.c:126 iptunnel_xmit+0x40c/0x8ec net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x19a0/0x28bc net/ipv4/ip_tunnel.c:840 __gre_xmit net/ipv4/ip_gre.c:474 [inline] gre_tap_xmit+0x400/0x5e0 net/ipv4/ip_gre.c:751 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x25c/0x9a4 net/core/dev.c:3643 sch_direct_xmit+0x234/0x548 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3854 [inline] __dev_queue_xmit+0x1658/0x38d8 net/core/dev.c:4259 dev_queue_xmit include/linux/netdevice.h:3021 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xd78/0x1a88 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:201 [inline] ip6_finish_output+0x5a4/0x940 net/ipv6/ip6_output.c:212 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x270/0x594 net/ipv6/ip6_output.c:233 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xc38/0x179c net/ipv6/ndisc.c:509 ndisc_send_rs+0x47c/0x5d4 net/ipv6/ndisc.c:719 addrconf_rs_timer+0x300/0x58c net/ipv6/addrconf.c:3961 call_timer_fn+0x1c0/0xa1c kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x554/0x718 kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 __do_softirq+0x314/0xe38 kernel/softirq.c:571 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x264/0x4d4 kernel/softirq.c:650 irq_exit_rcu+0x14/0x84 kernel/softirq.c:662 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] mod_lruvec_page_state include/linux/vmstat.h:563 [inline] lruvec_stat_mod_folio include/linux/vmstat.h:639 [inline] __folio_start_writeback+0x788/0xaf8 mm/page-writeback.c:3005 set_page_writeback+0x5c/0x7c mm/folio-compat.c:56 f2fs_do_write_meta_page+0x240/0x79c fs/f2fs/segment.c:3407 __f2fs_write_meta_page+0x37c/0x97c fs/f2fs/checkpoint.c:339 f2fs_sync_meta_pages+0x4b8/0x7b0 fs/f2fs/checkpoint.c:443 do_checkpoint+0x1e74/0x3830 fs/f2fs/checkpoint.c:1578 f2fs_write_checkpoint+0x10cc/0x17a0 fs/f2fs/checkpoint.c:1704 f2fs_issue_checkpoint+0x280/0x3b0 f2fs_sync_fs+0x1e4/0x580 fs/f2fs/super.c:1694 sync_filesystem+0x1a0/0x218 fs/sync.c:66 generic_shutdown_super+0x70/0x328 fs/super.c:474 kill_block_super+0x70/0xdc fs/super.c:1459 kill_f2fs_super+0x264/0x328 fs/f2fs/super.c:4652 deactivate_locked_super+0xac/0x124 fs/super.c:332 deactivate_super+0xf0/0x110 fs/super.c:363 cleanup_mnt+0x394/0x41c fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0x240/0x2f0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x2148/0x3474 arch/arm64/kernel/signal.c:1132 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585