------------[ cut here ]------------ kernfs_put: syz2/pids.events: released with incorrect active_ref 0 WARNING: CPU: 1 PID: 158 at fs/kernfs/dir.c:531 kernfs_put.part.0+0x433/0x540 Modules linked in: CPU: 1 PID: 158 Comm: kworker/1:3 Not tainted 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 Workqueue: events kernfs_notify_workfn RIP: 0010:kernfs_put.part.0+0x433/0x540 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 ------------[ cut here ]------------ RSP: 0018:ffff88801897fbd8 EFLAGS: 00010286 WARNING: CPU: 0 PID: 5328 at fs/kernfs/dir.c:504 kernfs_get.part.0+0x69/0x80 Modules linked in: RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 CPU: 0 PID: 5328 Comm: syz-executor.3 Not tainted 5.19.0-rc4-next-20220701 #1 RDX: ffff88800fab8000 RSI: ffffffff812b6848 RDI: ffffed100312ff6d 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 RBP: ffff88800fdcba30 R08: 0000000000000005 R09: 0000000000000000 RSP: 0018:ffff88806ce09c80 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88800fdcb9f8 RCX: 0000000000000100 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800fdcb9f8 RDX: ffff88800ef41ac0 RSI: ffffffff819d2579 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888016c60658 R14: 0000000000000000 R15: ffff888016d938e8 R13: 1ffffffff0a01e40 R14: ffff88800fdcb9f8 R15: ffff888043187130 FS: 00007f0825a65700(0000) GS:ffff88806ce00000(0000) knlGS:0000000000000000 FS: 0000000000000000(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fec408fb000 CR3: 00000000431cc000 CR4: 0000000000350ef0 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Call Trace: CR2: 00005555568f3098 CR3: 00000000443a2000 CR4: 0000000000350ee0 kernfs_get+0x1b/0x30 kernfs_notify+0x180/0x350 Call Trace: cgroup_file_notify+0xf5/0x1a0 kernfs_put+0x42/0x50 call_timer_fn+0x17d/0x5f0 kernfs_notify_workfn+0x417/0x560 process_one_work+0xa0f/0x1690 __run_timers.part.0+0x65e/0xa50 worker_thread+0x637/0x1250 run_timer_softirq+0xae/0x1a0 __do_softirq+0x1c8/0x8cc kthread+0x2ed/0x3a0 __irq_exit_rcu+0x113/0x170 irq_exit_rcu+0x5/0x20 ret_from_fork+0x22/0x30 sysvec_apic_timer_interrupt+0x8e/0xc0 irq event stamp: 359175 asm_sysvec_apic_timer_interrupt+0x1b/0x20 hardirqs last enabled at (359185): [] asm_sysvec_apic_timer_interrupt+0x1b/0x20 RIP: 0010:unlock_page+0x2f/0x130 hardirqs last disabled at (359194): [] sysvec_apic_timer_interrupt+0xb/0xc0 Code: fd 53 e8 14 03 e8 ff 48 8d 7d 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e4 00 00 00 4c 8b 65 08 <31> ff 4c 89 e3 83 e3 01 48 89 de e8 d1 ff e7 ff 48 85 db 0f 85 b8 softirqs last enabled at (358822): [] __irq_exit_rcu+0x113/0x170 RSP: 0018:ffff888048eb7868 EFLAGS: 00000246 softirqs last disabled at (358791): [] __irq_exit_rcu+0x113/0x170 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc900053b9000 ---[ end trace 0000000000000000 ]--- RDX: 1ffffd400019e211 RSI: ffffffff815c691c RDI: ffffea0000cf1088 RBP: ffffea0000cf1080 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffea0000c6e288 ================================================================== R13: ffff88801ab622b8 R14: ffff88801ab622b8 R15: 0000000000000000 BUG: KASAN: use-after-free in llist_del_first+0x89/0xa0 Read of size 8 at addr ffff88800fdcba78 by task kworker/1:3/158 CPU: 1 PID: 158 Comm: kworker/1:3 Tainted: G W 5.19.0-rc4-next-20220701 #1 __block_write_full_page+0x7b3/0x1190 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 Call Trace: block_write_full_page+0x14d/0x190 dump_stack_lvl+0x8b/0xb3 __writepage+0x67/0x180 print_report.cold+0x5e/0x5e1 write_cache_pages+0x48c/0x1190 kasan_report+0xb1/0x1b0 llist_del_first+0x89/0xa0 kernfs_notify_workfn+0x78/0x560 generic_writepages+0xe2/0x150 process_one_work+0xa0f/0x1690 do_writepages+0x1b0/0x690 worker_thread+0x637/0x1250 kthread+0x2ed/0x3a0 ret_from_fork+0x22/0x30 Allocated by task 293: kasan_save_stack+0x1e/0x40 filemap_fdatawrite_wbc+0x143/0x1b0 __kasan_slab_alloc+0x66/0x80 __filemap_fdatawrite_range+0xb6/0xf0 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 sync_blockdev_nowait+0x5b/0x80 css_populate_dir+0x19b/0x450 sync_filesystem.part.0+0xbb/0x1e0 cgroup_apply_control_enable+0x3ae/0xa40 __x64_sys_syncfs+0x19d/0x250 cgroup_mkdir+0x824/0x11f0 do_syscall_64+0x3b/0x90 kernfs_iop_mkdir+0x149/0x1d0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 vfs_mkdir+0x417/0x6a0 RIP: 0033:0x7f08284efb19 do_mkdirat+0x17b/0x2e0 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 __x64_sys_mkdir+0xf2/0x140 RSP: 002b:00007f0825a65188 EFLAGS: 00000246 do_syscall_64+0x3b/0x90 ORIG_RAX: 0000000000000132 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RAX: ffffffffffffffda RBX: 00007f0828602f60 RCX: 00007f08284efb19 Freed by task 158: RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 kasan_save_stack+0x1e/0x40 RBP: 00007f0828549f6d R08: 0000000000000000 R09: 0000000000000000 kasan_set_track+0x21/0x30 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 kasan_set_free_info+0x20/0x30 R13: 00007ffc6bd7965f R14: 00007f0825a65300 R15: 0000000000022000 __kasan_slab_free+0x108/0x190 kmem_cache_free+0xfb/0x600 irq event stamp: 45391 kernfs_put.part.0+0x2c7/0x540 hardirqs last enabled at (45390): [] asm_sysvec_apic_timer_interrupt+0x1b/0x20 kernfs_put+0x42/0x50 hardirqs last disabled at (45391): [] _raw_spin_lock_irqsave+0x4e/0x50 kernfs_notify_workfn+0x417/0x560 softirqs last enabled at (45060): [] __irq_exit_rcu+0x113/0x170 process_one_work+0xa0f/0x1690 softirqs last disabled at (45355): [] __irq_exit_rcu+0x113/0x170 worker_thread+0x637/0x1250 ---[ end trace 0000000000000000 ]--- kthread+0x2ed/0x3a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff88800fdcb9f8 which belongs to the cache kernfs_node_cache of size 168 The buggy address is located 128 bytes inside of 168-byte region [ffff88800fdcb9f8, ffff88800fdcbaa0) The buggy address belongs to the physical page: page:00000000f38bda74 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xfdcb 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: ffff88800fdcb900: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88800fdcb980: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa >ffff88800fdcba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88800fdcba80: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00 ffff88800fdcbb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. ---------------- Code disassembly (best guess): 0: fd std 1: 53 push %rbx 2: e8 14 03 e8 ff callq 0xffe8031b 7: 48 8d 7d 08 lea 0x8(%rbp),%rdi b: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 12: fc ff df 15: 48 89 fa mov %rdi,%rdx 18: 48 c1 ea 03 shr $0x3,%rdx 1c: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 20: 0f 85 e4 00 00 00 jne 0x10a 26: 4c 8b 65 08 mov 0x8(%rbp),%r12 * 2a: 31 ff xor %edi,%edi <-- trapping instruction 2c: 4c 89 e3 mov %r12,%rbx 2f: 83 e3 01 and $0x1,%ebx 32: 48 89 de mov %rbx,%rsi 35: e8 d1 ff e7 ff callq 0xffe8000b 3a: 48 85 db test %rbx,%rbx 3d: 0f .byte 0xf 3e: 85 .byte 0x85 3f: b8 .byte 0xb8