===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 5.10.45 #1 Not tainted ----------------------------------------------------- syz-executor.5/7712 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff88800fb796a8 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1004 [inline] ffff88800fb796a8 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync fs/fcntl.c:1025 [inline] ffff88800fb796a8 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync+0x14d/0x470 fs/fcntl.c:1018 and this task is already holding: ffff88806ce31340 (batched_entropy_u64.lock){-.-.}-{2:2}, at: get_random_u64+0x46/0x1d0 drivers/char/random.c:2200 which would create a new lock dependency: (batched_entropy_u64.lock){-.-.}-{2:2} -> (&new->fa_lock){.+.+}-{2:2} but this new dependency connects a HARDIRQ-irq-safe lock: (batched_entropy_u64.lock){-.-.}-{2:2} ... which became HARDIRQ-irq-safe at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x27/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] invalidate_batched_entropy+0xdf/0x1c0 drivers/char/random.c:2253 crng_fast_load+0x243/0x260 drivers/char/random.c:896 add_interrupt_randomness+0x523/0x650 drivers/char/random.c:1283 handle_irq_event_percpu kernel/irq/handle.c:198 [inline] handle_irq_event+0x13f/0x290 kernel/irq/handle.c:213 handle_edge_irq+0x249/0xd00 kernel/irq/chip.c:819 asm_call_irq_on_stack+0x12/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:230 [inline] __common_interrupt arch/x86/kernel/irq.c:249 [inline] common_interrupt+0xe6/0x190 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:635 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] default_idle+0xe/0x10 arch/x86/kernel/process.c:688 default_idle_call+0x87/0xd0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x3a9/0x520 kernel/sched/idle.c:300 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 start_kernel+0x481/0x4a2 init/main.c:1061 secondary_startup_64_no_verify+0xc2/0xcb to a HARDIRQ-irq-unsafe lock: (&new->fa_lock){.+.+}-{2:2} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3de/0x15f0 fs/locks.c:1657 break_lease include/linux/fs.h:2432 [inline] break_lease include/linux/fs.h:2422 [inline] do_dentry_open+0x43f/0x1090 fs/open.c:808 do_open fs/namei.c:3243 [inline] path_openat+0x1933/0x26f0 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16d/0x420 fs/open.c:1172 do_sys_open fs/open.c:1188 [inline] __do_sys_openat fs/open.c:1204 [inline] __se_sys_openat fs/open.c:1199 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1199 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&new->fa_lock); local_irq_disable(); lock(batched_entropy_u64.lock); lock(&new->fa_lock); lock(batched_entropy_u64.lock); *** DEADLOCK *** 2 locks held by syz-executor.5/7712: #0: ffff88806ce31340 (batched_entropy_u64.lock){-.-.}-{2:2}, at: get_random_u64+0x46/0x1d0 drivers/char/random.c:2200 #1: ffffffff84df64a0 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x3d/0x470 fs/fcntl.c:1023 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (batched_entropy_u64.lock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x27/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] invalidate_batched_entropy+0xdf/0x1c0 drivers/char/random.c:2253 crng_fast_load+0x243/0x260 drivers/char/random.c:896 add_interrupt_randomness+0x523/0x650 drivers/char/random.c:1283 handle_irq_event_percpu kernel/irq/handle.c:198 [inline] handle_irq_event+0x13f/0x290 kernel/irq/handle.c:213 handle_edge_irq+0x249/0xd00 kernel/irq/chip.c:819 asm_call_irq_on_stack+0x12/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:230 [inline] __common_interrupt arch/x86/kernel/irq.c:249 [inline] common_interrupt+0xe6/0x190 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:635 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] default_idle+0xe/0x10 arch/x86/kernel/process.c:688 default_idle_call+0x87/0xd0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x3a9/0x520 kernel/sched/idle.c:300 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 start_kernel+0x481/0x4a2 init/main.c:1061 secondary_startup_64_no_verify+0xc2/0xcb IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159 get_random_u64+0x46/0x1d0 drivers/char/random.c:2200 get_random_long include/linux/random.h:61 [inline] prandom_reseed+0x18c/0x430 lib/random32.c:509 call_timer_fn+0x182/0x580 kernel/time/timer.c:1410 expire_timers kernel/time/timer.c:1455 [inline] __run_timers.part.0+0x666/0x9e0 kernel/time/timer.c:1747 __run_timers kernel/time/timer.c:1728 [inline] run_timer_softirq+0x80/0x120 kernel/time/timer.c:1760 __do_softirq+0x1b8/0x85f kernel/softirq.c:298 asm_call_irq_on_stack+0x12/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x80/0xa0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x110/0x1a0 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x43/0xa0 arch/x86/kernel/apic/apic.c:1095 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:644 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] lock_release+0x3b4/0x6b0 kernel/locking/lockdep.c:5467 slab_pre_alloc_hook mm/slab.h:512 [inline] slab_alloc_node mm/slub.c:2813 [inline] slab_alloc mm/slub.c:2896 [inline] kmem_cache_alloc+0x43/0x350 mm/slub.c:2901 vm_area_alloc+0x1c/0x110 kernel/fork.c:348 mmap_region+0x815/0x15c0 mm/mmap.c:1777 do_mmap+0xcee/0x11f0 mm/mmap.c:1583 vm_mmap_pgoff+0x194/0x1f0 mm/util.c:507 ksys_mmap_pgoff+0x43e/0x570 mm/mmap.c:1634 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159 get_random_u64+0x46/0x1d0 drivers/char/random.c:2200 get_random_long include/linux/random.h:61 [inline] get_random_canary include/linux/random.h:83 [inline] dup_task_struct kernel/fork.c:911 [inline] copy_process+0x7f4/0x6640 kernel/fork.c:1947 kernel_clone+0xe7/0xa20 kernel/fork.c:2465 kernel_thread+0xb5/0xf0 kernel/fork.c:2517 rest_init+0x23/0x371 init/main.c:687 start_kernel+0x481/0x4a2 init/main.c:1061 secondary_startup_64_no_verify+0xc2/0xcb } ... key at: [] 0xffff88806ce31340 ... acquired at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 account drivers/char/random.c:1381 [inline] extract_entropy drivers/char/random.c:1508 [inline] crng_reseed+0xb12/0xcf0 drivers/char/random.c:958 _extract_crng+0x1e6/0x250 drivers/char/random.c:1006 crng_reseed+0x776/0xcf0 drivers/char/random.c:962 _extract_crng+0x1e6/0x250 drivers/char/random.c:1006 extract_crng drivers/char/random.c:1026 [inline] get_random_u64+0x159/0x1d0 drivers/char/random.c:2202 get_random_long include/linux/random.h:61 [inline] get_random_canary include/linux/random.h:83 [inline] dup_task_struct kernel/fork.c:911 [inline] copy_process+0x7f4/0x6640 kernel/fork.c:1947 kernel_clone+0xe7/0xa20 kernel/fork.c:2465 __do_sys_clone+0xc8/0x110 kernel/fork.c:2582 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (&new->fa_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3de/0x15f0 fs/locks.c:1657 break_lease include/linux/fs.h:2432 [inline] break_lease include/linux/fs.h:2422 [inline] do_dentry_open+0x43f/0x1090 fs/open.c:808 do_open fs/namei.c:3243 [inline] path_openat+0x1933/0x26f0 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16d/0x420 fs/open.c:1172 do_sys_open fs/open.c:1188 [inline] __do_sys_openat fs/open.c:1204 [inline] __se_sys_openat fs/open.c:1199 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1199 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3de/0x15f0 fs/locks.c:1657 break_lease include/linux/fs.h:2432 [inline] break_lease include/linux/fs.h:2422 [inline] do_dentry_open+0x43f/0x1090 fs/open.c:808 do_open fs/namei.c:3243 [inline] path_openat+0x1933/0x26f0 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16d/0x420 fs/open.c:1172 do_sys_open fs/open.c:1188 [inline] __do_sys_openat fs/open.c:1204 [inline] __se_sys_openat fs/open.c:1199 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1199 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0x2f/0x40 kernel/locking/spinlock.c:311 fasync_remove_entry+0xb6/0x1f0 fs/fcntl.c:882 fasync_helper+0x9e/0xb0 fs/fcntl.c:985 __fput+0x743/0x980 fs/file_table.c:278 task_work_run+0xe2/0x1a0 kernel/task_work.c:151 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:164 [inline] exit_to_user_mode_prepare+0x155/0x160 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x230 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3de/0x15f0 fs/locks.c:1657 break_lease include/linux/fs.h:2432 [inline] break_lease include/linux/fs.h:2422 [inline] do_dentry_open+0x43f/0x1090 fs/open.c:808 do_open fs/namei.c:3243 [inline] path_openat+0x1933/0x26f0 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16d/0x420 fs/open.c:1172 do_sys_open fs/open.c:1188 [inline] __do_sys_openat fs/open.c:1204 [inline] __se_sys_openat fs/open.c:1199 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1199 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 } ... key at: [] __key.0+0x0/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 account drivers/char/random.c:1381 [inline] extract_entropy drivers/char/random.c:1508 [inline] crng_reseed+0xb12/0xcf0 drivers/char/random.c:958 _extract_crng+0x1e6/0x250 drivers/char/random.c:1006 crng_reseed+0x776/0xcf0 drivers/char/random.c:962 _extract_crng+0x1e6/0x250 drivers/char/random.c:1006 extract_crng drivers/char/random.c:1026 [inline] get_random_u64+0x159/0x1d0 drivers/char/random.c:2202 get_random_long include/linux/random.h:61 [inline] get_random_canary include/linux/random.h:83 [inline] dup_task_struct kernel/fork.c:911 [inline] copy_process+0x7f4/0x6640 kernel/fork.c:1947 kernel_clone+0xe7/0xa20 kernel/fork.c:2465 __do_sys_clone+0xc8/0x110 kernel/fork.c:2582 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 stack backtrace: CPU: 0 PID: 7712 Comm: syz-executor.5 Not tainted 5.10.45 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 print_bad_irq_dependency kernel/locking/lockdep.c:2453 [inline] check_irq_usage.cold+0x481/0x58d kernel/locking/lockdep.c:2682 check_prev_add kernel/locking/lockdep.c:2873 [inline] check_prevs_add kernel/locking/lockdep.c:2994 [inline] validate_chain kernel/locking/lockdep.c:3609 [inline] __lock_acquire+0x2a60/0x5a80 kernel/locking/lockdep.c:4834 lock_acquire kernel/locking/lockdep.c:5444 [inline] lock_acquire+0x197/0x6c0 kernel/locking/lockdep.c:5409 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x58/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1004 [inline] kill_fasync fs/fcntl.c:1025 [inline] kill_fasync+0x14d/0x470 fs/fcntl.c:1018 account drivers/char/random.c:1381 [inline] extract_entropy drivers/char/random.c:1508 [inline] crng_reseed+0xb12/0xcf0 drivers/char/random.c:958 _extract_crng+0x1e6/0x250 drivers/char/random.c:1006 crng_reseed+0x776/0xcf0 drivers/char/random.c:962 _extract_crng+0x1e6/0x250 drivers/char/random.c:1006 extract_crng drivers/char/random.c:1026 [inline] get_random_u64+0x159/0x1d0 drivers/char/random.c:2202 get_random_long include/linux/random.h:61 [inline] get_random_canary include/linux/random.h:83 [inline] dup_task_struct kernel/fork.c:911 [inline] copy_process+0x7f4/0x6640 kernel/fork.c:1947 kernel_clone+0xe7/0xa20 kernel/fork.c:2465 __do_sys_clone+0xc8/0x110 kernel/fork.c:2582 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x464bfb Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffd376911e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464bfb RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000002057400 R10: 00000000020576d0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffd376912d0