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BUG: KASAN: use-after-free in mas_safe_min lib/maple_tree.c:715 [inline]
BUG: KASAN: use-after-free in mas_next_nentry+0x9e4/0xab0 lib/maple_tree.c:4612
Read of size 8 at addr ffff88807f999820 by task syz-executor.0/3629

CPU: 1 PID: 3629 Comm: syz-executor.0 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:317 [inline]
 print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
 kasan_report+0xbe/0x1f0 mm/kasan/report.c:495
 mas_safe_min lib/maple_tree.c:715 [inline]
 mas_next_nentry+0x9e4/0xab0 lib/maple_tree.c:4612
 mas_next_entry lib/maple_tree.c:4707 [inline]
 mas_next+0x1fb/0xc90 lib/maple_tree.c:5805
 userfaultfd_unregister fs/userfaultfd.c:1651 [inline]
 userfaultfd_ioctl+0x33de/0x41d0 fs/userfaultfd.c:2001
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f444fa89279
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf2ca6bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f444fb9bf80 RCX: 00007f444fa89279
RDX: 0000000020000180 RSI: 000000008010aa01 RDI: 0000000000000003
RBP: 00007f444fae3189 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f444fba0350 R14: 00007f444fb9bf80 R15: 0000000000000000
 </TASK>

Allocated by task 3612:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:736 [inline]
 kmem_cache_alloc_bulk+0x383/0x730 mm/slub.c:3735
 mt_alloc_bulk lib/maple_tree.c:151 [inline]
 mas_alloc_nodes+0x2b0/0x6b0 lib/maple_tree.c:1244
 mas_node_count+0x101/0x130 lib/maple_tree.c:1303
 mas_expected_entries+0x10b/0x1b0 lib/maple_tree.c:5719
 dup_mmap+0x4c4/0x1070 kernel/fork.c:613
 dup_mm+0x91/0x370 kernel/fork.c:1520
 copy_mm kernel/fork.c:1569 [inline]
 copy_process+0x3ca8/0x7080 kernel/fork.c:2237
 kernel_clone+0xe7/0xab0 kernel/fork.c:2652
 __do_sys_clone+0xba/0x100 kernel/fork.c:2786
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Freed by task 3629:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1754 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
 slab_free mm/slub.c:3534 [inline]
 kmem_cache_free_bulk mm/slub.c:3660 [inline]
 kmem_cache_free_bulk+0x20e/0x780 mm/slub.c:3648
 mt_free_bulk lib/maple_tree.c:157 [inline]
 mas_destroy+0x394/0x5c0 lib/maple_tree.c:5767
 mas_store_prealloc+0xec/0x150 lib/maple_tree.c:5646
 __vma_adjust+0x6d7/0x1900 mm/mmap.c:835
 vma_adjust include/linux/mm.h:2678 [inline]
 __split_vma+0x443/0x530 mm/mmap.c:2302
 split_vma+0x9f/0xe0 mm/mmap.c:2335
 userfaultfd_unregister fs/userfaultfd.c:1630 [inline]
 userfaultfd_ioctl+0x38ba/0x41d0 fs/userfaultfd.c:2001
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

The buggy address belongs to the object at ffff88807f999800
 which belongs to the cache maple_node of size 256
The buggy address is located 32 bytes inside of
 256-byte region [ffff88807f999800, ffff88807f999900)

The buggy address belongs to the physical page:
page:ffffea0001fe6600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f998
head:ffffea0001fe6600 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001ddc980 dead000000000006 ffff88801184fdc0
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3409, tgid 3409 (sed), ts 38597772442, free_ts 25415055592
 prep_new_page mm/page_alloc.c:2535 [inline]
 get_page_from_freelist+0x210d/0x3a30 mm/page_alloc.c:4282
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5506
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2280
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x27e/0x3d0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x89d/0xef0 mm/slub.c:3031
 kmem_cache_alloc_bulk+0x21c/0x730 mm/slub.c:3711
 mt_alloc_bulk lib/maple_tree.c:151 [inline]
 mas_alloc_nodes+0x2b0/0x6b0 lib/maple_tree.c:1244
 mas_preallocate+0xff/0x2d0 lib/maple_tree.c:5662
 do_mas_align_munmap+0x11c/0xee0 mm/mmap.c:2376
 do_mas_munmap+0x202/0x2c0 mm/mmap.c:2564
 mmap_region+0x219/0x1bf0 mm/mmap.c:2612
 do_mmap+0x825/0xf50 mm/mmap.c:1483
 vm_mmap_pgoff+0x1ab/0x270 mm/util.c:520
 ksys_mmap_pgoff+0x79/0x5a0 mm/mmap.c:1529
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1453 [inline]
 free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1503
 free_unref_page_prepare mm/page_alloc.c:3383 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3479
 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:736 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3258 [inline]
 kmem_cache_alloc+0x2d6/0x4c0 mm/slub.c:3268
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139
 getname_flags+0x9a/0xe0 include/linux/audit.h:321
 user_path_at_empty+0x2b/0x60 fs/namei.c:2894
 do_readlinkat+0xcd/0x2f0 fs/stat.c:456
 __do_sys_readlink fs/stat.c:489 [inline]
 __se_sys_readlink fs/stat.c:486 [inline]
 __x64_sys_readlink+0x74/0xb0 fs/stat.c:486
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Memory state around the buggy address:
 ffff88807f999700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807f999780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807f999800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88807f999880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807f999900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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