(syz.4.85,6442,1):ocfs2_test_inode_bit:3231 ERROR: get alloc slot and bit failed -12 (syz.4.85,6442,1):ocfs2_test_inode_bit:3276 ERROR: status = -12 (syz.4.85,6442,1):ocfs2_get_dentry:78 ERROR: test inode bit failed -12 ================================================================== BUG: KASAN: slab-use-afte[ 135.647292][ T6442] BUG: KASAN: slab-use-after-free in ocfs2_fault+0xdb/0x440 fs/ocfs2/mmap.c:41 Read of size 8 at addr ffff888036b5bb98 by task syz.4.85/6442 CPU: 1 UID: 0 PID: 6442 Comm: syz.4.85 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 ocfs2_fault+0xdb/0x440 fs/ocfs2/mmap.c:41 __do_fault+0x138/0x390 mm/memory.c:5364 do_read_fault mm/memory.c:5799 [inline] do_fault mm/memory.c:5933 [inline] do_pte_missing+0x1825/0x29e0 mm/memory.c:4477 handle_pte_fault mm/memory.c:6317 [inline] __handle_mm_fault mm/memory.c:6455 [inline] handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6624 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0xb7/0x2b0 lib/strncpy_from_user.c:130 Code: 00 00 4c 89 f6 e8 b9 47 ea fc 49 83 fe 07 0f 86 9d 00 00 00 48 89 1c 24 4c 89 74 24 08 48 c7 c5 f8 ff ff ff 45 31 ff 4c 89 e3 <4f> 8b 34 3c 48 b8 ff fe fe fe fe fe fe fe 4d 8d 24 06 4d 89 f5 49 RSP: 0018:ffffc90006dafe30 EFLAGS: 00050246 RAX: ffffffff84da4417 RBX: 0000200000001040 RCX: ffff88802dce1e80 RDX: 0000000000000002 RSI: 00000000000000a8 RDI: 0000000000000007 RBP: fffffffffffffff8 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1006ec4a38 R12: 0000200000001040 R13: 0000200000001040 R14: 00000000000000a8 R15: 0000000000000000 do_getname+0x77/0x250 fs/namei.c:193 getname_flags fs/namei.c:225 [inline] getname include/linux/fs.h:2512 [inline] class_filename_constructor include/linux/fs.h:2539 [inline] __do_sys_mknod fs/namei.c:5184 [inline] __se_sys_mknod+0x24/0x150 fs/namei.c:5182 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2bed1ec819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2beb43e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f2bed465fa0 RCX: 00007f2bed1ec819 RDX: 0000000000000d02 RSI: 0000000000000020 RDI: 0000200000001040 RBP: 00007f2bed282c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2bed466038 R14: 00007f2bed465fa0 R15: 00007ffc7033d448 Allocated by task 6442: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4873 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 __mmap_new_vma mm/vma.c:2517 [inline] __mmap_region mm/vma.c:2759 [inline] mmap_region+0x112c/0x2230 mm/vma.c:2837 do_mmap+0xc2f/0x10c0 mm/mmap.c:559 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581 ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:605 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 20: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free_after_rcu_debug+0x126/0x220 mm/slub.c:6230 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core kernel/rcu/tree.c:2869 [inline] rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 slab_free_hook mm/slub.c:2646 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x4fb/0x6b0 mm/slub.c:6295 remove_vma mm/vma.c:470 [inline] vms_complete_munmap_vmas+0x929/0xc60 mm/vma.c:1342 __mmap_complete+0x7b/0x5e0 mm/vma.c:2588 __mmap_region mm/vma.c:2768 [inline] mmap_region+0x15ed/0x2230 mm/vma.c:2837 do_mmap+0xc2f/0x10c0 mm/mmap.c:559 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581 ksys_mmap_pgoff+0x550/0x720 mm/mmap.c:605 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888036b5bb40 which belongs to the cache vm_area_struct of size 256 The buggy address is located 88 bytes inside of freed 256-byte region [ffff888036b5bb40, ffff888036b5bc40) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x36b5b memcg:ffff888036b5bf01 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801b29fb40 dead000000000122 0000000000000000 raw: 0000000000000000 00000008000c000c 00000000f5000000 ffff888036b5bf01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5854, tgid 5854 (udevd), ts 135350264343, free_ts 135344096354 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x77/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x35c/0x710 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4873 vm_area_dup+0x2b/0x670 mm/vma_init.c:123 __split_vma+0x1e4/0xa30 mm/vma.c:513 vms_gather_munmap_vmas+0x4fa/0x1370 mm/vma.c:1429 do_vmi_align_munmap+0x2c7/0x4d0 mm/vma.c:1576 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1633 __vm_munmap+0x22c/0x3d0 mm/vma.c:3254 __do_sys_munmap mm/mmap.c:1078 [inline] __se_sys_munmap mm/mmap.c:1075 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1075 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 6452 tgid 6452 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978 tlb_batch_list_free mm/mmu_gather.c:161 [inline] tlb_finish_mmu+0x144/0x230 mm/mmu_gather.c:533 exit_mmap+0x498/0xa10 mm/mmap.c:1315 __mmput+0xcb/0x3d0 kernel/fork.c:1175 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x6a2/0x23c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 __do_sys_exit_group kernel/exit.c:1129 [inline] __se_sys_exit_group kernel/exit.c:1127 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1127 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888036b5ba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888036b5bb00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888036b5bb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888036b5bc00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888036b5bc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 4c 89 f6 mov %r14,%rsi 5: e8 b9 47 ea fc call 0xfcea47c3 a: 49 83 fe 07 cmp $0x7,%r14 e: 0f 86 9d 00 00 00 jbe 0xb1 14: 48 89 1c 24 mov %rbx,(%rsp) 18: 4c 89 74 24 08 mov %r14,0x8(%rsp) 1d: 48 c7 c5 f8 ff ff ff mov $0xfffffffffffffff8,%rbp 24: 45 31 ff xor %r15d,%r15d 27: 4c 89 e3 mov %r12,%rbx * 2a: 4f 8b 34 3c mov (%r12,%r15,1),%r14 <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 4d 8d 24 06 lea (%r14,%rax,1),%r12 3c: 4d 89 f5 mov %r14,%r13 3f: 49 rex.WB