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BUG: KASAN: use-after-free in mas_safe_min lib/maple_tree.c:721 [inline]
BUG: KASAN: use-after-free in mas_next_nentry+0x9e4/0xab0 lib/maple_tree.c:4662
Read of size 8 at addr ffff88801c036c20 by task syz-executor.3/28940

CPU: 2 PID: 28940 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-12255-g2df76606db9d #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
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:284 [inline]
 print_report+0x15e/0x461 mm/kasan/report.c:395
 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495
 mas_safe_min lib/maple_tree.c:721 [inline]
 mas_next_nentry+0x9e4/0xab0 lib/maple_tree.c:4662
 mas_next_entry lib/maple_tree.c:4757 [inline]
 mas_next+0x1fb/0xc90 lib/maple_tree.c:5868
 userfaultfd_unregister fs/userfaultfd.c:1657 [inline]
 userfaultfd_ioctl+0x33c3/0x4200 fs/userfaultfd.c:2005
 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+0x63/0xcd
RIP: 0033:0x7f0cf368b5a9
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:00007f0cf4733168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0cf37abf80 RCX: 00007f0cf368b5a9
RDX: 0000000020000140 RSI: 000000008010aa01 RDI: 0000000000000003
RBP: 00007f0cf36e6580 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff3ebe9b8f R14: 00007f0cf4733300 R15: 0000000000022000
 </TASK>

Allocated by task 3690:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45
 kasan_set_track+0x21/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x7b/0x80 mm/kasan/common.c:325
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slab.h:737 [inline]
 kmem_cache_alloc_bulk+0x2fb/0x480 mm/slab.c:3509
 mt_alloc_bulk lib/maple_tree.c:157 [inline]
 mas_alloc_nodes+0x309/0x810 lib/maple_tree.c:1256
 mas_node_count_gfp+0x106/0x140 lib/maple_tree.c:1316
 mas_node_count lib/maple_tree.c:1330 [inline]
 mas_expected_entries+0x113/0x200 lib/maple_tree.c:5822
 dup_mmap+0x4ca/0x10b0 kernel/fork.c:613
 dup_mm+0x91/0x370 kernel/fork.c:1526
 copy_mm kernel/fork.c:1575 [inline]
 copy_process+0x3bc6/0x7190 kernel/fork.c:2253
 kernel_clone+0xe7/0x980 kernel/fork.c:2671
 __do_sys_clone+0xba/0x100 kernel/fork.c:2812
 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+0x63/0xcd

Freed by task 28940:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45
 kasan_set_track+0x21/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:177 [inline]
 __cache_free mm/slab.c:3389 [inline]
 kmem_cache_free_bulk+0xf3/0x460 mm/slab.c:3644
 mt_free_bulk lib/maple_tree.c:163 [inline]
 mas_destroy+0x394/0x5c0 lib/maple_tree.c:5769
 mas_store_prealloc+0xec/0x150 lib/maple_tree.c:5704
 __vma_adjust+0xc47/0x1a70 mm/mmap.c:783
 vma_adjust include/linux/mm.h:2663 [inline]
 __split_vma+0x4b0/0x5c0 mm/mmap.c:2236
 split_vma+0x9f/0xe0 mm/mmap.c:2272
 userfaultfd_unregister fs/userfaultfd.c:1636 [inline]
 userfaultfd_ioctl+0x3855/0x4200 fs/userfaultfd.c:2005
 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+0x63/0xcd

The buggy address belongs to the object at ffff88801c036c00
 which belongs to the cache maple_node of size 256
The buggy address is located 32 bytes inside of
 256-byte region [ffff88801c036c00, ffff88801c036d00)

The buggy address belongs to the physical page:
page:ffffea0000700d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c036
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00008e8948 ffffea000074fec8 ffff88801186f100
raw: 0000000000000000 ffff88801c036000 0000000100000008 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 3457, tgid 3457 (dhcpcd-run-hook), ts 39811106408, free_ts 39477524815
 prep_new_page mm/page_alloc.c:2538 [inline]
 get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287
 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5554
 __alloc_pages_node include/linux/gfp.h:223 [inline]
 kmem_getpages mm/slab.c:1363 [inline]
 cache_grow_begin+0x75/0x360 mm/slab.c:2570
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943
 ____cache_alloc mm/slab.c:3019 [inline]
 ____cache_alloc mm/slab.c:3002 [inline]
 __do_cache_alloc mm/slab.c:3202 [inline]
 kmem_cache_alloc_bulk+0x34b/0x480 mm/slab.c:3495
 mt_alloc_bulk lib/maple_tree.c:157 [inline]
 mas_alloc_nodes+0x309/0x810 lib/maple_tree.c:1256
 mas_node_count_gfp lib/maple_tree.c:1316 [inline]
 mas_preallocate+0x1b7/0x360 lib/maple_tree.c:5719
 __vma_adjust+0x181/0x1a70 mm/mmap.c:715
 vma_adjust include/linux/mm.h:2663 [inline]
 __split_vma+0x295/0x5c0 mm/mmap.c:2239
 split_vma+0x9f/0xe0 mm/mmap.c:2272
 mprotect_fixup+0x746/0x960 mm/mprotect.c:623
 do_mprotect_pkey+0x6fd/0xa70 mm/mprotect.c:792
 __do_sys_mprotect mm/mprotect.c:819 [inline]
 __se_sys_mprotect mm/mprotect.c:816 [inline]
 __x64_sys_mprotect+0x74/0xb0 mm/mprotect.c:816
 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+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1458 [inline]
 free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1508
 free_unref_page_prepare mm/page_alloc.c:3386 [inline]
 free_unref_page+0x19/0x4d0 mm/page_alloc.c:3482
 __folio_put_small mm/swap.c:105 [inline]
 __folio_put+0xc1/0x130 mm/swap.c:128
 folio_put include/linux/mm.h:1159 [inline]
 put_page include/linux/mm.h:1211 [inline]
 free_page_and_swap_cache+0x253/0x2c0 mm/swap_state.c:299
 __tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline]
 __tlb_remove_table_free mm/mmu_gather.c:115 [inline]
 tlb_remove_table_rcu+0x85/0xe0 mm/mmu_gather.c:170
 rcu_do_batch kernel/rcu/tree.c:2248 [inline]
 rcu_core+0x81f/0x1980 kernel/rcu/tree.c:2508
 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571

Memory state around the buggy address:
 ffff88801c036b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801c036b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801c036c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88801c036c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801c036d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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