Hello,

syzbot found the following issue on:

HEAD commit: bbed346d5a96 Merge branch 'for-next/core' into for-kernelci git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=14c82f39880000 kernel config: https://syzkaller.appspot.com/x/.config?x=3a4a45d2d827c1e dashboard link: https://syzkaller.appspot.com/bug?extid=6d6c13e35721fb4393fd compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/e8e91bc79312/disk-bbed346d.raw.... vmlinux: https://storage.googleapis.com/syzbot-assets/c1cb3fb3b77e/vmlinux-bbed346d.x...

IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6d6c13e35721fb4393fd@syzkaller.appspotmail.com

================================ WARNING: inconsistent lock state 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor.4/21937 [HC0[0]:SC0[0]:HE0:SE1] takes: ffff80000d6384c8 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] ffff80000d6384c8 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x54/0x2dc drivers/dma-buf/sync_debug.c:147 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x6c/0xb4 kernel/locking/spinlock.c:162 sync_timeline_debug_remove+0x24/0x80 drivers/dma-buf/sync_debug.c:31 sync_timeline_free drivers/dma-buf/sw_sync.c:104 [inline] kref_put include/linux/kref.h:65 [inline] sync_timeline_put drivers/dma-buf/sw_sync.c:116 [inline] timeline_fence_release+0xe0/0x15c drivers/dma-buf/sw_sync.c:144 dma_fence_release+0x70/0x11c drivers/dma-buf/dma-fence.c:549 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] dma_fence_array_release+0xac/0x154 drivers/dma-buf/dma-fence-array.c:120 dma_fence_release+0x70/0x11c drivers/dma-buf/dma-fence.c:549 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] irq_dma_fence_array_work+0x84/0x11c drivers/dma-buf/dma-fence-array.c:52 irq_work_single kernel/irq_work.c:211 [inline] irq_work_run_list kernel/irq_work.c:242 [inline] irq_work_run+0xc4/0x29c kernel/irq_work.c:251 do_handle_IPI arch/arm64/kernel/smp.c:899 [inline] ipi_handler+0x120/0x1a8 arch/arm64/kernel/smp.c:922 handle_percpu_devid_irq+0xb0/0x1c8 kernel/irq/chip.c:930 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq_desc kernel/irq/irqdesc.c:648 [inline] generic_handle_domain_irq+0x4c/0x6c kernel/irq/irqdesc.c:704 __gic_handle_irq drivers/irqchip/irq-gic-v3.c:695 [inline] __gic_handle_irq_from_irqson drivers/irqchip/irq-gic-v3.c:746 [inline] gic_handle_irq+0x78/0x1b4 drivers/irqchip/irq-gic-v3.c:790 call_on_irq_stack+0x2c/0x54 arch/arm64/kernel/entry.S:889 do_interrupt_handler+0x7c/0xc0 arch/arm64/kernel/entry-common.c:274 __el1_irq arch/arm64/kernel/entry-common.c:470 [inline] el1_interrupt+0x34/0x68 arch/arm64/kernel/entry-common.c:485 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:490 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:577 arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x44/0x70 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:399 [inline] sw_sync_debugfs_release+0xa8/0x158 drivers/dma-buf/sw_sync.c:321 __fput+0x198/0x3dc fs/file_table.c:320 ____fput+0x20/0x30 fs/file_table.c:353 task_work_run+0xc4/0x14c kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x26c/0xbe0 kernel/exit.c:795 __arm64_sys_exit_group+0x0/0x18 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __wake_up_parent+0x0/0x40 kernel/exit.c:934 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 irq event stamp: 872 hardirqs last enabled at (871): [<ffff8000085633bc>] mod_objcg_state+0x19c/0x204 mm/memcontrol.c:3158 hardirqs last disabled at (872): [<ffff80000bfc8834>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] hardirqs last disabled at (872): [<ffff80000bfc8834>] _raw_spin_lock_irq+0x34/0x9c kernel/locking/spinlock.c:170 softirqs last enabled at (856): [<ffff80000801c33c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (854): [<ffff80000801c308>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19

other info that might help us debug this: Possible unsafe locking scenario:

CPU0 ---- lock(sync_timeline_list_lock); <Interrupt> lock(sync_timeline_list_lock);

*** DEADLOCK ***

3 locks held by syz-executor.4/21937: #0: ffff000128868ee8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x12c/0x154 fs/file.c:1036 #1: ffff000126e66d50 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x5c/0x5e0 fs/seq_file.c:182 #2: ffff80000d6384c8 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] #2: ffff80000d6384c8 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x54/0x2dc drivers/dma-buf/sync_debug.c:147

stack backtrace: CPU: 0 PID: 21937 Comm: syz-executor.4 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_usage_bug+0x39c/0x3cc kernel/locking/lockdep.c:3961 mark_lock_irq+0x4a8/0x4b4 mark_lock+0x154/0x1b4 kernel/locking/lockdep.c:4632 mark_held_locks kernel/locking/lockdep.c:4234 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:4252 [inline] lockdep_hardirqs_on_prepare+0x158/0x2b0 kernel/locking/lockdep.c:4319 trace_hardirqs_on+0xc4/0x108 kernel/trace/trace_preemptirq.c:49 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x3c/0x70 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:399 [inline] sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline] sync_info_debugfs_show+0xd8/0x2dc drivers/dma-buf/sync_debug.c:153 seq_read_iter+0x220/0x5e0 fs/seq_file.c:230 seq_read+0x98/0xd0 fs/seq_file.c:162 vfs_read+0x19c/0x448 fs/read_write.c:468 ksys_read+0xb4/0x160 fs/read_write.c:607 __do_sys_read fs/read_write.c:617 [inline] __se_sys_read fs/read_write.c:615 [inline] __arm64_sys_read+0x24/0x34 fs/read_write.c:615 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

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