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BUG: KASAN: slab-use-after-free in ocfs2_fault+0xdb/0x440 fs/ocfs2/mmap.c:41
Read of size 8 at addr ffff888012255418 by task syz.0.0/5315

CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 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:5355
 do_read_fault mm/memory.c:5790 [inline]
 do_fault mm/memory.c:5924 [inline]
 do_pte_missing+0x228f/0x3750 mm/memory.c:4469
 handle_pte_fault mm/memory.c:6308 [inline]
 __handle_mm_fault mm/memory.c:6446 [inline]
 handle_mm_fault+0x1bec/0x3310 mm/memory.c:6615
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x165b/0x29d0 mm/gup.c:1428
 populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
 __mm_populate+0x25f/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:3689 [inline]
 vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
 ksys_mmap_pgoff+0x51e/0x760 mm/mmap.c:604
 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: 0033:0x7f58b399bf79
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:00007f58b4772028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f58b3c16090 RCX: 00007f58b399bf79
RDX: 00000000027ffff7 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f58b3a327e0 R08: 000000000000000a R09: 0000000000004000
R10: 0000000004012011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f58b3c16128 R14: 00007f58b3c16090 R15: 00007ffc54d4d078
 </TASK>

Allocated by task 5315:
 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:4459 [inline]
 slab_alloc_node mm/slub.c:4788 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4795
 vm_area_alloc+0x24/0x140 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2510 [inline]
 __mmap_region mm/vma.c:2752 [inline]
 mmap_region+0xf90/0x1f50 mm/vma.c:2830
 do_mmap+0xc39/0x10c0 mm/mmap.c:558
 vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
 ksys_mmap_pgoff+0x51e/0x760 mm/mmap.c:604
 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 5288:
 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:2670 [inline]
 slab_free_after_rcu_debug+0x126/0x220 mm/slub.c:6147
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

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:2631 [inline]
 slab_free mm/slub.c:6082 [inline]
 kmem_cache_free+0x426/0x630 mm/slub.c:6212
 remove_vma mm/vma.c:467 [inline]
 vms_complete_munmap_vmas+0x625/0x890 mm/vma.c:1336
 __mmap_complete+0x7b/0x5e0 mm/vma.c:2581
 __mmap_region mm/vma.c:2761 [inline]
 mmap_region+0x1430/0x1f50 mm/vma.c:2830
 do_mmap+0xc39/0x10c0 mm/mmap.c:558
 vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
 ksys_mmap_pgoff+0x51e/0x760 mm/mmap.c:604
 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 ffff8880122553c0
 which belongs to the cache vm_area_struct of size 256
The buggy address is located 88 bytes inside of
 freed 256-byte region [ffff8880122553c0, ffff8880122554c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12255
memcg:ffff88801fd39281
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff888030411500 dead000000000100 dead000000000122
raw: 0000000000000000 00000008000c000c 00000000f5000000 ffff88801fd39281
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 4690, tgid 4690 (rcS), ts 32092047142, free_ts 31448758694
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1888
 prep_new_page mm/page_alloc.c:1896 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3961
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5249
 alloc_slab_page mm/slub.c:3238 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3411
 new_slab mm/slub.c:3469 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7091
 refill_sheaf mm/slub.c:2787 [inline]
 __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4536
 alloc_from_pcs mm/slub.c:4639 [inline]
 slab_alloc_node mm/slub.c:4773 [inline]
 kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4795
 vm_area_dup+0x2b/0x680 mm/vma_init.c:123
 dup_mmap+0x8b7/0x1b80 mm/mmap.c:1773
 dup_mm kernel/fork.c:1530 [inline]
 copy_mm+0x13b/0x4b0 kernel/fork.c:1582
 copy_process+0x18b6/0x3cf0 kernel/fork.c:2223
 kernel_clone+0x248/0x8e0 kernel/fork.c:2654
 __do_sys_clone kernel/fork.c:2795 [inline]
 __se_sys_clone kernel/fork.c:2779 [inline]
 __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2779
 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 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1432 [inline]
 __free_frozen_pages+0xc00/0xd90 mm/page_alloc.c:2977
 __free_pages mm/page_alloc.c:5368 [inline]
 free_reserved_page+0xce/0x120 mm/page_alloc.c:6277
 free_reserved_area+0x90/0x190 mm/page_alloc.c:6263
 free_init_pages arch/x86/mm/init.c:936 [inline]
 free_kernel_image_pages+0xa2/0x100 arch/x86/mm/init.c:952
 kernel_init+0x31/0x1d0 init/main.c:1591
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888012255300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888012255380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff888012255400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888012255480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888012255500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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