------------[ cut here ]------------ kernfs_put: syz3/memory.events.local: released with incorrect active_ref 0 WARNING: CPU: 1 PID: 84 at fs/kernfs/dir.c:531 kernfs_put.part.0+0x433/0x540 ------------[ cut here ]------------ Modules linked in: WARNING: CPU: 0 PID: 4323 at fs/kernfs/dir.c:504 kernfs_get.part.0+0x69/0x80 CPU: 1 PID: 84 Comm: kworker/1:3 Not tainted 5.19.0-rc4-next-20220701 #1 Modules linked in: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 CPU: 0 PID: 4323 Comm: syz-executor.4 Not tainted 5.19.0-rc4-next-20220701 #1 Workqueue: events kernfs_notify_workfn Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 RIP: 0010:kernfs_get.part.0+0x69/0x80 Code: 31 ff 89 ee e8 a8 43 a7 ff 85 ed 74 18 e8 cf 46 a7 ff be 04 00 00 00 48 89 df e8 52 be d9 ff f0 ff 03 5b 5d c3 e8 b7 46 a7 ff <0f> 0b eb df 48 89 df e8 fb ba d9 ff eb c6 66 0f 1f 84 00 00 00 00 RSP: 0018:ffff88806ce09c80 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88801b62f828 RCX: 0000000000000100 RIP: 0010:kernfs_put.part.0+0x433/0x540 RDX: ffff8880451e1ac0 RSI: ffffffff819d2579 RDI: 0000000000000005 Code: 03 80 3c 18 00 0f 85 ea 00 00 00 4d 8b 7d 38 e8 53 42 a7 ff 48 8b 14 24 44 89 f1 4c 89 fe 48 c7 c7 a0 58 72 84 e8 97 1c 6c 02 <0f> 0b e9 b9 fc ff ff 48 89 ef e8 8e b6 d9 ff e9 c1 fd ff ff e8 84 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 RSP: 0018:ffff88800fa4fbd8 EFLAGS: 00010286 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: 1ffffffff0a01e40 R14: ffff88801b62f828 R15: ffff888045ea04f0 FS: 00007f82e5737700(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d735000 CR3: 0000000008610000 CR4: 0000000000350ef0 Call Trace: kernfs_get+0x1b/0x30 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 kernfs_notify+0x180/0x350 cgroup_file_notify+0xf5/0x1a0 RDX: ffff88800fb1b580 RSI: ffffffff812b6848 RDI: ffffed1001f49f6d RBP: ffff88801b62f860 R08: 0000000000000005 R09: 0000000000000000 call_timer_fn+0x17d/0x5f0 R10: 0000000080000000 R11: 0000000000000001 R12: ffff88801b62f828 R13: ffff88800dc4de80 R14: 0000000000000000 R15: ffff88800ec125a0 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2dd2b000 CR3: 0000000008610000 CR4: 0000000000350ee0 __run_timers.part.0+0x65e/0xa50 Call Trace: run_timer_softirq+0xae/0x1a0 kernfs_put+0x42/0x50 __do_softirq+0x1c8/0x8cc __irq_exit_rcu+0x113/0x170 kernfs_notify_workfn+0x417/0x560 irq_exit_rcu+0x5/0x20 sysvec_apic_timer_interrupt+0x8e/0xc0 asm_sysvec_apic_timer_interrupt+0x1b/0x20 RIP: 0010:kvm_flush_tlb_multi+0x2/0x310 process_one_work+0xa0f/0x1690 Code: a4 c6 7d 04 72 d8 5b 5d 41 5c 41 5d c3 48 c7 c7 40 94 8e 85 e8 cf 12 66 00 eb e3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 <41> 56 41 55 49 bd 00 00 00 00 00 fc ff df 41 54 55 48 c7 c5 c0 72 RSP: 0018:ffff888046c77870 EFLAGS: 00000297 RAX: 0000000000000003 RBX: ffff888016f1d400 RCX: 1ffffffff0b1d288 RDX: 0000000000000000 RSI: ffff88806ce37480 RDI: ffff888016f1da78 RBP: ffff88806ce37480 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888016f1da78 R14: ffffffffffffffff R15: 0000000000000000 worker_thread+0x637/0x1250 flush_tlb_mm_range+0x297/0x3a0 tlb_finish_mmu+0x33c/0x7f0 kthread+0x2ed/0x3a0 unmap_region+0x261/0x2f0 do_mas_align_munmap.constprop.0+0x924/0xff0 ret_from_fork+0x22/0x30 irq event stamp: 389937 hardirqs last enabled at (389945): [] console_emit_next_record.constprop.0+0x648/0x800 do_mas_munmap+0x1e8/0x2b0 mmap_region+0x21c/0x19f0 hardirqs last disabled at (389954): [] console_emit_next_record.constprop.0+0x667/0x800 softirqs last enabled at (389488): [] __irq_exit_rcu+0x113/0x170 softirqs last disabled at (389467): [] __irq_exit_rcu+0x113/0x170 do_mmap+0x824/0xf40 vm_mmap_pgoff+0x1ab/0x270 ---[ end trace 0000000000000000 ]--- ksys_mmap_pgoff+0x3cc/0x4f0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f82e81c1b62 Code: 00 00 00 00 00 0f 1f 00 41 f7 c1 ff 0f 00 00 75 27 55 48 89 fd 53 89 cb 48 85 ff 74 3b 41 89 da 48 89 ef b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 5b 5d c3 0f 1f 00 48 c7 c0 bc ff ff ff 64 RSP: 002b:00007f82e57370f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000008011 RCX: 00007f82e81c1b62 RDX: 0000000000000003 RSI: 0000000000200000 RDI: 0000000020ffc000 RBP: 0000000020ffc000 R08: 0000000000000008 R09: 0000000010000000 R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020000300 R13: 0000000020ffc000 R14: 0000000020000200 R15: 0000000020ffe000 irq event stamp: 8099 hardirqs last enabled at (8098): [] _raw_spin_unlock_irq+0x1f/0x40 hardirqs last disabled at (8099): [] _raw_spin_lock_irqsave+0x4e/0x50 softirqs last enabled at (7884): [] __irq_exit_rcu+0x113/0x170 softirqs last disabled at (8073): [] __irq_exit_rcu+0x113/0x170 ---[ end trace 0000000000000000 ]--- ================================================================== BUG: KASAN: use-after-free in kernfs_get.part.0+0x5e/0x80 Write of size 4 at addr ffff88801b62f828 by task syz-executor.4/4323 CPU: 0 PID: 4323 Comm: syz-executor.4 Tainted: G W 5.19.0-rc4-next-20220701 #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_lvl+0x8b/0xb3 print_report.cold+0x5e/0x5e1 kasan_report+0xb1/0x1b0 kasan_check_range+0x35/0x1b0 kernfs_get.part.0+0x5e/0x80 kernfs_get+0x1b/0x30 kernfs_notify+0x180/0x350 cgroup_file_notify+0xf5/0x1a0 call_timer_fn+0x17d/0x5f0 __run_timers.part.0+0x65e/0xa50 run_timer_softirq+0xae/0x1a0 __do_softirq+0x1c8/0x8cc __irq_exit_rcu+0x113/0x170 irq_exit_rcu+0x5/0x20 sysvec_apic_timer_interrupt+0x8e/0xc0 asm_sysvec_apic_timer_interrupt+0x1b/0x20 RIP: 0010:kvm_flush_tlb_multi+0x2/0x310 Code: a4 c6 7d 04 72 d8 5b 5d 41 5c 41 5d c3 48 c7 c7 40 94 8e 85 e8 cf 12 66 00 eb e3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 <41> 56 41 55 49 bd 00 00 00 00 00 fc ff df 41 54 55 48 c7 c5 c0 72 RSP: 0018:ffff888046c77870 EFLAGS: 00000297 RAX: 0000000000000003 RBX: ffff888016f1d400 RCX: 1ffffffff0b1d288 RDX: 0000000000000000 RSI: ffff88806ce37480 RDI: ffff888016f1da78 RBP: ffff88806ce37480 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888016f1da78 R14: ffffffffffffffff R15: 0000000000000000 flush_tlb_mm_range+0x297/0x3a0 tlb_finish_mmu+0x33c/0x7f0 unmap_region+0x261/0x2f0 do_mas_align_munmap.constprop.0+0x924/0xff0 do_mas_munmap+0x1e8/0x2b0 mmap_region+0x21c/0x19f0 do_mmap+0x824/0xf40 vm_mmap_pgoff+0x1ab/0x270 ksys_mmap_pgoff+0x3cc/0x4f0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f82e81c1b62 Code: 00 00 00 00 00 0f 1f 00 41 f7 c1 ff 0f 00 00 75 27 55 48 89 fd 53 89 cb 48 85 ff 74 3b 41 89 da 48 89 ef b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 5b 5d c3 0f 1f 00 48 c7 c0 bc ff ff ff 64 RSP: 002b:00007f82e57370f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000008011 RCX: 00007f82e81c1b62 RDX: 0000000000000003 RSI: 0000000000200000 RDI: 0000000020ffc000 RBP: 0000000020ffc000 R08: 0000000000000008 R09: 0000000010000000 R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020000300 R13: 0000000020ffc000 R14: 0000000020000200 R15: 0000000020ffe000 Allocated by task 297: kasan_save_stack+0x1e/0x40 __kasan_slab_alloc+0x66/0x80 kmem_cache_alloc+0x1b1/0x490 __kernfs_new_node+0xd4/0x8b0 kernfs_new_node+0x93/0x120 __kernfs_create_file+0x51/0x350 cgroup_addrm_files+0x3e2/0x9d0 css_populate_dir+0x19b/0x450 cgroup_apply_control_enable+0x3ae/0xa40 cgroup_mkdir+0x824/0x11f0 kernfs_iop_mkdir+0x149/0x1d0 vfs_mkdir+0x417/0x6a0 do_mkdirat+0x17b/0x2e0 __x64_sys_mkdir+0xf2/0x140 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 84: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x108/0x190 kmem_cache_free+0xfb/0x600 kernfs_put.part.0+0x2c7/0x540 kernfs_put+0x42/0x50 kernfs_notify_workfn+0x417/0x560 process_one_work+0xa0f/0x1690 worker_thread+0x637/0x1250 kthread+0x2ed/0x3a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff88801b62f828 which belongs to the cache kernfs_node_cache of size 168 The buggy address is located 0 bytes inside of 168-byte region [ffff88801b62f828, ffff88801b62f8d0) The buggy address belongs to the physical page: page:0000000087ea8829 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b62f flags: 0x100000000000200(slab|node=0|zone=1) raw: 0100000000000200 0000000000000000 dead000000000122 ffff8880080718c0 raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801b62f700: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88801b62f780: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc >ffff88801b62f800: fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb ^ ffff88801b62f880: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff88801b62f900: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 7d 04 jge 0x6 2: 72 d8 jb 0xffffffdc 4: 5b pop %rbx 5: 5d pop %rbp 6: 41 5c pop %r12 8: 41 5d pop %r13 a: c3 retq b: 48 c7 c7 40 94 8e 85 mov $0xffffffff858e9440,%rdi 12: e8 cf 12 66 00 callq 0x6612e6 17: eb e3 jmp 0xfffffffc 19: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 20: 00 00 00 00 24: 66 90 xchg %ax,%ax 26: 41 57 push %r15 * 28: 41 56 push %r14 <-- trapping instruction 2a: 41 55 push %r13 2c: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 33: fc ff df 36: 41 54 push %r12 38: 55 push %rbp 39: 48 rex.W 3a: c7 .byte 0xc7 3b: c5 .byte 0xc5 3c: c0 .byte 0xc0 3d: 72 .byte 0x72