================================================================== BUG: KFENCE: use-after-free read in __lock_acquire+0xd87/0x54a0 kernel/locking/lockdep.c:4885 Use-after-free read at 0xffff88823bc7a7a0 (in kfence-#60): __lock_acquire+0xd87/0x54a0 kernel/locking/lockdep.c:4885 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:368 [inline] aio_poll_cancel+0x3e/0x290 fs/aio.c:1661 free_ioctx_users+0xa4/0x230 fs/aio.c:622 percpu_ref_put_many.constprop.0+0x22b/0x260 include/linux/percpu-refcount.h:322 rcu_do_batch kernel/rcu/tree.c:2506 [inline] rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] folio_memcg_lock+0x3a/0x3e0 mm/memcontrol.c:1984 page_remove_rmap+0x25/0x1480 mm/rmap.c:1348 zap_pte_range mm/memory.c:1362 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xed5/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x620 mm/mmap.c:3194 __mmput+0x122/0x470 kernel/fork.c:1154 mmput+0x58/0x60 kernel/fork.c:1175 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae kfence-#60: 0xffff88823bc7a740-0xffff88823bc7afd7, size=2200, cache=sighand_cache allocated by task 8798 on cpu 0 at 2851.561024s: copy_sighand kernel/fork.c:1573 [inline] copy_process+0x2354/0x7580 kernel/fork.c:2165 kernel_clone+0xe7/0xac0 kernel/fork.c:2561 __do_sys_clone+0xc8/0x110 kernel/fork.c:2678 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae freed by task 8802 on cpu 0 at 2851.627381s: rcu_do_batch kernel/rcu/tree.c:2506 [inline] rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] folio_memcg_lock+0x3a/0x3e0 mm/memcontrol.c:1984 page_remove_rmap+0x25/0x1480 mm/rmap.c:1348 zap_pte_range mm/memory.c:1362 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xed5/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x620 mm/mmap.c:3194 __mmput+0x122/0x470 kernel/fork.c:1154 mmput+0x58/0x60 kernel/fork.c:1175 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae CPU: 0 PID: 8802 Comm: syz-executor.4 Not tainted 5.14.0-next-20210901-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xd87/0x54a0 kernel/locking/lockdep.c:4885 Code: c8 00 00 00 89 05 69 fd e9 0d e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 0f 85 f3 2f 00 00 <48> 81 3b 40 44 f0 8e 0f 84 52 f3 ff ff 41 83 fa 01 0f 87 5a f3 ff RSP: 0018:ffffc90000007b60 EFLAGS: 00010046 RAX: dffffc0000000000 RBX: ffff88823bc7a7a0 RCX: 0000000000000000 RDX: 1ffff1104778f4f4 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880799e8000 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823bc7a7a0 CR3: 00000000782f2000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:368 [inline] aio_poll_cancel+0x3e/0x290 fs/aio.c:1661 free_ioctx_users+0xa4/0x230 fs/aio.c:622 percpu_ref_put_many.constprop.0+0x22b/0x260 include/linux/percpu-refcount.h:322 rcu_do_batch kernel/rcu/tree.c:2506 [inline] rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 Code: 95 a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90019d2f618 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920033a5ec5 RCX: 42f1125c69a15e59 RDX: 1ffff1100f33d13f RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fd00927 R10: fffffbfff1fa0124 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8b97fbe0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] folio_memcg_lock+0x3a/0x3e0 mm/memcontrol.c:1984 page_remove_rmap+0x25/0x1480 mm/rmap.c:1348 zap_pte_range mm/memory.c:1362 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xed5/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x620 mm/mmap.c:3194 __mmput+0x122/0x470 kernel/fork.c:1154 mmput+0x58/0x60 kernel/fork.c:1175 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007f612d70a218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 000000000056bf88 RCX: 00000000004665f9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000056bf8c RBP: 000000000056bf80 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c R13: 00007ffc3ac4f64f R14: 00007f612d70a300 R15: 0000000000022000 ================================================================== ---------------- Code disassembly (best guess): 0: c8 00 00 00 enterq $0x0,$0x0 4: 89 05 69 fd e9 0d mov %eax,0xde9fd69(%rip) # 0xde9fd73 a: e9 bd 00 00 00 jmpq 0xcc f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 16: fc ff df 19: 48 89 da mov %rbx,%rdx 1c: 48 c1 ea 03 shr $0x3,%rdx 20: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 24: 0f 85 f3 2f 00 00 jne 0x301d * 2a: 48 81 3b 40 44 f0 8e cmpq $0xffffffff8ef04440,(%rbx) <-- trapping instruction 31: 0f 84 52 f3 ff ff je 0xfffff389 37: 41 83 fa 01 cmp $0x1,%r10d 3b: 0f .byte 0xf 3c: 87 5a f3 xchg %ebx,-0xd(%rdx) 3f: ff .byte 0xff