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BUG: KASAN: slab-use-after-free in ocfs2_fault+0xd3/0x3e0 fs/ocfs2/mmap.c:41
Read of size 8 at addr ffff888043ac7a58 by task syz.0.0/5345

CPU: 0 UID: 0 PID: 5345 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~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 ocfs2_fault+0xd3/0x3e0 fs/ocfs2/mmap.c:41
 __do_fault+0x138/0x390 mm/memory.c:5320
 do_read_fault mm/memory.c:5755 [inline]
 do_fault mm/memory.c:5889 [inline]
 do_pte_missing+0x2206/0x3330 mm/memory.c:4401
 handle_pte_fault mm/memory.c:6273 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1650/0x29f0 mm/gup.c:1428
 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860
 __mm_populate+0x24c/0x380 mm/gup.c:1963
 mm_populate include/linux/mm.h:3701 [inline]
 vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586
 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0dcc98f7c9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0dcd809038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f0dccbe6180 RCX: 00007f0dcc98f7c9
RDX: 00000000027ffff7 RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f0dcca13f91 R08: 0000000000000004 R09: 0000000000004000
R10: 0000000004012011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0dccbe6218 R14: 00007f0dccbe6180 R15: 00007fff5f3a7258
 </TASK>

Allocated by task 5345:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4948 [inline]
 slab_alloc_node mm/slub.c:5258 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5265
 vm_area_alloc+0x24/0x140 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2469 [inline]
 __mmap_region mm/vma.c:2708 [inline]
 mmap_region+0xdea/0x1d10 mm/vma.c:2786
 do_mmap+0xc45/0x10d0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581
 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 15:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free_after_rcu_debug+0x125/0x260 mm/slub.c:6722
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 slab_free_hook mm/slub.c:2501 [inline]
 slab_free mm/slub.c:6663 [inline]
 kmem_cache_free+0x475/0x620 mm/slub.c:6774
 remove_vma mm/vma.c:462 [inline]
 vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1296
 __mmap_complete+0x7b/0x610 mm/vma.c:2540
 __mmap_region mm/vma.c:2717 [inline]
 mmap_region+0x11e3/0x1d10 mm/vma.c:2786
 do_mmap+0xc45/0x10d0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581
 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888043ac7a00
 which belongs to the cache vm_area_struct of size 256
The buggy address is located 88 bytes inside of
 freed 256-byte region [ffff888043ac7a00, ffff888043ac7b00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43ac7
memcg:ffff88804326e001
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff888030412b40 ffffea0000ff3bc0 dead000000000004
raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88804326e001
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 4730, tgid 4730 (udevd), ts 42470586155, free_ts 42451044856
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xf2b/0x1960 mm/slub.c:4651
 __kmem_cache_alloc_bulk+0x1d9/0x550 mm/slub.c:7424
 refill_sheaf mm/slub.c:2650 [inline]
 __pcs_replace_empty_main+0x298/0x560 mm/slub.c:5018
 alloc_from_pcs mm/slub.c:5116 [inline]
 slab_alloc_node mm/slub.c:5243 [inline]
 kmem_cache_alloc_noprof+0x469/0x710 mm/slub.c:5265
 vm_area_dup+0x2b/0x680 mm/vma_init.c:123
 dup_mmap+0x870/0x1b80 mm/mmap.c:1773
 dup_mm kernel/fork.c:1529 [inline]
 copy_mm+0x13c/0x4b0 kernel/fork.c:1581
 copy_process+0x165d/0x3950 kernel/fork.c:2221
 kernel_clone+0x21e/0x820 kernel/fork.c:2651
 __do_sys_clone kernel/fork.c:2792 [inline]
 __se_sys_clone kernel/fork.c:2776 [inline]
 __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
page last free pid 15 tgid 15 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Memory state around the buggy address:
 ffff888043ac7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888043ac7980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888043ac7a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff888043ac7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888043ac7b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
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