================================================================== ================================================================== BUG: KASAN: use-after-free in mas_safe_min lib/maple_tree.c:715 [inline] BUG: KASAN: use-after-free in mas_next_nentry+0x997/0xaa0 lib/maple_tree.c:4546 Read of size 8 at addr ffff888073eeae18 by task syz-executor854/3593 CPU: 0 PID: 3593 Comm: syz-executor854 Not tainted 5.18.0-rc4-next-20220427-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 mas_safe_min lib/maple_tree.c:715 [inline] mas_next_nentry+0x997/0xaa0 lib/maple_tree.c:4546 mas_next_entry lib/maple_tree.c:4636 [inline] mas_next+0x1eb/0xc40 lib/maple_tree.c:5723 userfaultfd_register fs/userfaultfd.c:1468 [inline] userfaultfd_ioctl+0x2527/0x40f0 fs/userfaultfd.c:1993 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+0x44/0xae RIP: 0033:0x7efe7583e939 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 00 00 90 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:00007fff4c9a23d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000031 RCX: 00007efe7583e939 RDX: 0000000020000080 RSI: 00000000c020aa00 RDI: 0000000000000003 RBP: 00007fff4c9a24d0 R08: 00007fff4c9a2432 R09: 00007fff4c9a2432 R10: 00007fff4c9a2432 R11: 0000000000000246 R12: 00007fff4c9a24a0 R13: 00007efe758c24e0 R14: 0000000000000003 R15: 00007fff4c9a2432 Allocated by task 3592: 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:750 [inline] kmem_cache_alloc_bulk+0x39f/0x720 mm/slub.c:3728 mt_alloc_bulk lib/maple_tree.c:151 [inline] mas_alloc_nodes+0x1df/0x6b0 lib/maple_tree.c:1244 mas_node_count+0x101/0x130 lib/maple_tree.c:1303 mas_split lib/maple_tree.c:3406 [inline] mas_commit_b_node lib/maple_tree.c:3508 [inline] mas_wr_modify+0x2505/0x5ac0 lib/maple_tree.c:4251 mas_wr_store_entry.isra.0+0x66e/0x10f0 lib/maple_tree.c:4289 mas_store+0xac/0xf0 lib/maple_tree.c:5523 dup_mmap+0x845/0x1030 kernel/fork.c:687 dup_mm+0x91/0x370 kernel/fork.c:1516 copy_mm kernel/fork.c:1565 [inline] copy_process+0x3b07/0x6fd0 kernel/fork.c:2226 kernel_clone+0xe7/0xab0 kernel/fork.c:2631 __do_sys_clone+0xc8/0x110 kernel/fork.c:2748 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+0x44/0xae Freed by task 3593: 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+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1727 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1753 slab_free mm/slub.c:3507 [inline] kmem_cache_free_bulk mm/slub.c:3654 [inline] kmem_cache_free_bulk+0x2c0/0xb60 mm/slub.c:3641 mt_free_bulk lib/maple_tree.c:157 [inline] mas_destroy+0x394/0x5c0 lib/maple_tree.c:5685 mas_store_prealloc+0xec/0x150 lib/maple_tree.c:5567 vma_mas_store mm/internal.h:482 [inline] __vma_adjust+0x6ba/0x18f0 mm/mmap.c:811 vma_adjust include/linux/mm.h:2654 [inline] __split_vma+0x443/0x530 mm/mmap.c:2259 split_vma+0x9f/0xe0 mm/mmap.c:2292 userfaultfd_register fs/userfaultfd.c:1444 [inline] userfaultfd_ioctl+0x39f4/0x40f0 fs/userfaultfd.c:1993 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+0x44/0xae The buggy address belongs to the object at ffff888073eeae00 which belongs to the cache maple_node of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff888073eeae00, ffff888073eeaf00) The buggy address belongs to the physical page: page:ffffea0001cfba80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73eea head:ffffea0001cfba80 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010c4fdc0 raw: 0000000000000000 0000000000100010 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 3592, tgid 3592 (syz-executor854), ts 49234311759, free_ts 49217281978 prep_new_page mm/page_alloc.c:2431 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4172 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5393 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2281 alloc_slab_page mm/slub.c:1797 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x985/0xd90 mm/slub.c:3002 kmem_cache_alloc_bulk+0x21c/0x720 mm/slub.c:3704 mt_alloc_bulk lib/maple_tree.c:151 [inline] mas_alloc_nodes+0x2b0/0x6b0 lib/maple_tree.c:1244 mas_preallocate+0xfb/0x270 lib/maple_tree.c:5581 mmap_region+0xd31/0x1c70 mm/mmap.c:2683 do_mmap+0x825/0xf60 mm/mmap.c:1471 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:488 ksys_mmap_pgoff+0x79/0x5a0 mm/mmap.c:1517 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+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1396 free_unref_page_prepare mm/page_alloc.c:3318 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3413 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:750 [inline] slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x204/0x3b0 mm/slub.c:3239 anon_vma_chain_alloc mm/rmap.c:140 [inline] __anon_vma_prepare+0x60/0x560 mm/rmap.c:194 anon_vma_prepare include/linux/rmap.h:151 [inline] do_anonymous_page mm/memory.c:4090 [inline] handle_pte_fault mm/memory.c:4917 [inline] __handle_mm_fault+0x3159/0x3530 mm/memory.c:5058 handle_mm_fault+0x1c8/0x790 mm/memory.c:5156 do_user_addr_fault+0x489/0x11c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1484 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1540 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:570 Memory state around the buggy address: ffff888073eead00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888073eead80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888073eeae00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888073eeae80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888073eeaf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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