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BUG: KASAN: slab-use-after-free in ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41
Read of size 8 at addr ffff888012951d18 by task syz.0.0/5323

CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.14.0-rc5-syzkaller-00218-g2a520073e74f #0
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 lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 ocfs2_fault+0xe9/0x3d0 fs/ocfs2/mmap.c:41
 __do_fault+0x135/0x390 mm/memory.c:4988
 do_read_fault mm/memory.c:5403 [inline]
 do_fault mm/memory.c:5537 [inline]
 do_pte_missing mm/memory.c:4058 [inline]
 handle_pte_fault mm/memory.c:5900 [inline]
 __handle_mm_fault+0x4c44/0x70f0 mm/memory.c:6043
 handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6212
 faultin_page mm/gup.c:1196 [inline]
 __get_user_pages+0x1a92/0x4140 mm/gup.c:1491
 populate_vma_page_range+0x264/0x330 mm/gup.c:1929
 __mm_populate+0x27a/0x460 mm/gup.c:2032
 mm_populate include/linux/mm.h:3386 [inline]
 vm_mmap_pgoff+0x303/0x430 mm/util.c:580
 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa6b578d169
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:00007fa6b1bf5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fa6b59a6080 RCX: 00007fa6b578d169
RDX: 000000000100000f RSI: 0000000000b36000 RDI: 0000400000000000
RBP: 00007fa6b580e2a0 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000000028011 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa6b59a6080 R15: 00007ffcda6eb758
 </TASK>

Allocated by task 5323:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171
 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472
 __mmap_new_vma mm/vma.c:2341 [inline]
 __mmap_region mm/vma.c:2457 [inline]
 mmap_region+0x1b04/0x2fa0 mm/vma.c:2535
 do_mmap+0xecc/0x13a0 mm/mmap.c:561
 vm_mmap_pgoff+0x214/0x430 mm/util.c:575
 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 47:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kmem_cache_free+0x195/0x410 mm/slub.c:4711
 rcu_do_batch kernel/rcu/tree.c:2546 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2802
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x312/0x3b0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xaa/0xc0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3065 [inline]
 call_rcu+0x168/0xac0 kernel/rcu/tree.c:3172
 remove_vma mm/vma.c:419 [inline]
 vms_complete_munmap_vmas+0x65b/0x8f0 mm/vma.c:1202
 __mmap_complete mm/vma.c:2407 [inline]
 __mmap_region mm/vma.c:2473 [inline]
 mmap_region+0x1998/0x2fa0 mm/vma.c:2535
 do_mmap+0xecc/0x13a0 mm/mmap.c:561
 vm_mmap_pgoff+0x214/0x430 mm/util.c:575
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888012951c98
 which belongs to the cache vm_area_struct of size 184
The buggy address is located 128 bytes inside of
 freed 184-byte region [ffff888012951c98, ffff888012951d50)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12951
memcg:ffff88801e5f0501
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801c280b40 ffffea0000489200 dead000000000005
raw: 0000000000000000 0000000080100010 00000000f5000000 ffff88801e5f0501
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4693, tgid 4693 (mount), ts 22128045603, free_ts 21909036948
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4171
 vm_area_dup+0x27/0x290 kernel/fork.c:487
 __split_vma+0x1bf/0xbf0 mm/vma.c:466
 vms_gather_munmap_vmas+0x2e6/0x1600 mm/vma.c:1268
 __mmap_prepare mm/vma.c:2242 [inline]
 __mmap_region mm/vma.c:2444 [inline]
 mmap_region+0xa50/0x2fa0 mm/vma.c:2535
 do_mmap+0xecc/0x13a0 mm/mmap.c:561
 vm_mmap_pgoff+0x214/0x430 mm/util.c:575
 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:607
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
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:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 free_reserved_page+0xcc/0x120 mm/page_alloc.c:5737
 free_reserved_area+0x51/0xf0 mm/page_alloc.c:5723
 free_init_pages arch/x86/mm/init.c:932 [inline]
 free_kernel_image_pages arch/x86/mm/init.c:948 [inline]
 free_initmem+0x9a/0x110 arch/x86/mm/init.c:975
 kernel_init+0x31/0x2b0 init/main.c:1466
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888012951c00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
 ffff888012951c80: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888012951d00: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
                            ^
 ffff888012951d80: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888012951e00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
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