------------[ cut here ]------------ kernfs_put: syz4/memory.events.local: released with incorrect active_ref 0 WARNING: CPU: 1 PID: 48 at fs/kernfs/dir.c:531 kernfs_put.part.0+0x433/0x540 Modules linked in: CPU: 1 PID: 48 Comm: kworker/1:2 Not tainted 5.19.0-rc5-next-20220706 #1 ------------[ cut here ]------------ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Workqueue: events kernfs_notify_workfn WARNING: CPU: 0 PID: 4185 at fs/kernfs/dir.c:504 kernfs_get.part.0+0x69/0x80 Modules linked in: CPU: 0 PID: 4185 Comm: syz-executor.0 Not tainted 5.19.0-rc5-next-20220706 #1 RIP: 0010:kernfs_put.part.0+0x433/0x540 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: 03 80 3c 18 00 0f 85 ea 00 00 00 4d 8b 7d 38 e8 53 fc a6 ff 48 8b 14 24 44 89 f1 4c 89 fe 48 c7 c7 e0 5b 72 84 e8 13 aa 6c 02 <0f> 0b e9 b9 fc ff ff 48 89 ef e8 0e b3 d9 ff e9 c1 fd ff ff e8 04 Code: 31 ff 89 ee e8 a8 fd a6 ff 85 ed 74 18 e8 cf 00 a7 ff be 04 00 00 00 48 89 df e8 d2 ba d9 ff f0 ff 03 5b 5d c3 e8 b7 00 a7 ff <0f> 0b eb df 48 89 df e8 7b b7 d9 ff eb c6 66 0f 1f 84 00 00 00 00 RSP: 0018:ffff88800f2f7bd8 EFLAGS: 00010286 RSP: 0018:ffff88806ce09c80 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88801828e570 RCX: 0000000000000100 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff888033281ac0 RSI: ffffffff819df849 RDI: 0000000000000005 RDX: ffff88800f2e8000 RSI: ffffffff812bd348 RDI: ffffed1001e5ef6d RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 RBP: ffff88801828e5a8 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: 1ffffffff0a01e40 R14: ffff88801828e570 R15: ffff888044c904f0 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801828e570 FS: 0000000000000000(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000 R13: ffff88800d4b4bc8 R14: 0000000000000000 R15: ffff888010ed36b8 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e025000 CR3: 000000001879e000 CR4: 0000000000350ef0 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 Call Trace: kernfs_get+0x1b/0x30 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernfs_notify+0x180/0x350 cgroup_file_notify+0xf5/0x1a0 CR2: 00005555565b0098 CR3: 00000000414a2000 CR4: 0000000000350ee0 Call Trace: 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:lock_acquire+0x1db/0x530 Code: 02 b8 ff ff ff ff 65 0f c1 05 f9 ff d8 7e 83 f8 01 0f 85 c4 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:ffff8880181174f0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff11003022ea0 RCX: 0000000051897313 RDX: 1ffff11006650486 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff86a607c7 R10: fffffbfff0d4c0f8 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff852049e0 R15: 0000000000000000 folio_memcg_lock+0x3a/0x3c0 page_remove_rmap+0x1e/0x490 unmap_page_range+0xe8f/0x2720 kernfs_put+0x42/0x50 kernfs_notify_workfn+0x417/0x560 unmap_single_vma+0x190/0x350 unmap_vmas+0x21e/0x370 process_one_work+0xa0f/0x1690 exit_mmap+0x154/0x680 worker_thread+0x637/0x1250 mmput+0xd1/0x390 do_exit+0xa01/0x27d0 kthread+0x2ed/0x3a0 ret_from_fork+0x22/0x30 irq event stamp: 200203 do_group_exit+0xd2/0x2f0 hardirqs last enabled at (200215): [] asm_sysvec_apic_timer_interrupt+0x1b/0x20 get_signal+0x2201/0x24b0 hardirqs last disabled at (200224): [] sysvec_apic_timer_interrupt+0xb/0xc0 softirqs last enabled at (200032): [] __irq_exit_rcu+0x113/0x170 softirqs last disabled at (199899): [] __irq_exit_rcu+0x113/0x170 ---[ end trace 0000000000000000 ]--- arch_do_signal_or_restart+0x89/0x1be0 exit_to_user_mode_prepare+0x131/0x1a0 syscall_exit_to_user_mode+0x19/0x40 do_syscall_64+0x48/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f6793382b19 Code: Unable to access opcode bytes at RIP 0x7f6793382aef. RSP: 002b:00007f67908f8218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f6793495f68 RCX: 00007f6793382b19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6793495f6c RBP: 00007f6793495f60 R08: 0000000000000009 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f6793495f6c R13: 00007ffc21c1ba9f R14: 00007f67908f8300 R15: 0000000000022000 irq event stamp: 1877 hardirqs last enabled at (1876): [] _raw_spin_unlock_irq+0x1f/0x40 hardirqs last disabled at (1877): [] _raw_spin_lock_irqsave+0x4e/0x50 softirqs last enabled at (1854): [] __irq_exit_rcu+0x113/0x170 softirqs last disabled at (1869): [] __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 ffff88801828e570 by task syz-executor.0/4185 CPU: 0 PID: 4185 Comm: syz-executor.0 Tainted: G W 5.19.0-rc5-next-20220706 #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:lock_acquire+0x1db/0x530 Code: 02 b8 ff ff ff ff 65 0f c1 05 f9 ff d8 7e 83 f8 01 0f 85 c4 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:ffff8880181174f0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff11003022ea0 RCX: 0000000051897313 RDX: 1ffff11006650486 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff86a607c7 R10: fffffbfff0d4c0f8 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff852049e0 R15: 0000000000000000 folio_memcg_lock+0x3a/0x3c0 page_remove_rmap+0x1e/0x490 unmap_page_range+0xe8f/0x2720 unmap_single_vma+0x190/0x350 unmap_vmas+0x21e/0x370 exit_mmap+0x154/0x680 mmput+0xd1/0x390 do_exit+0xa01/0x27d0 do_group_exit+0xd2/0x2f0 get_signal+0x2201/0x24b0 arch_do_signal_or_restart+0x89/0x1be0 exit_to_user_mode_prepare+0x131/0x1a0 syscall_exit_to_user_mode+0x19/0x40 do_syscall_64+0x48/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f6793382b19 Code: Unable to access opcode bytes at RIP 0x7f6793382aef. RSP: 002b:00007f67908f8218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f6793495f68 RCX: 00007f6793382b19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6793495f6c RBP: 00007f6793495f60 R08: 0000000000000009 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f6793495f6c R13: 00007ffc21c1ba9f R14: 00007f67908f8300 R15: 0000000000022000 Allocated by task 294: 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 48: 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 ffff88801828e570 which belongs to the cache kernfs_node_cache of size 168 The buggy address is located 0 bytes inside of 168-byte region [ffff88801828e570, ffff88801828e618) The buggy address belongs to the physical page: page:0000000013a77b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1828e flags: 0x100000000000200(slab|node=0|zone=1) raw: 0100000000000200 0000000000000000 dead000000000122 ffff8880080358c0 raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801828e400: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff88801828e480: fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88801828e500: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa fb ^ ffff88801828e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801828e600: fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 ================================================================== EXT4-fs (loop3): mounted filesystem without journal. Quota mode: none. EXT4-fs (loop3): unmounting filesystem. ---------------- Code disassembly (best guess): 0: 02 b8 ff ff ff ff add -0x1(%rax),%bh 6: 65 0f c1 05 f9 ff d8 xadd %eax,%gs:0x7ed8fff9(%rip) # 0x7ed90007 d: 7e e: 83 f8 01 cmp $0x1,%eax 11: 0f 85 c4 02 00 00 jne 0x2db 17: 48 83 7c 24 08 00 cmpq $0x0,0x8(%rsp) 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c3 add %rax,%rbx <-- trapping instruction 2d: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 34: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 3b: 00 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24