================================================================== BUG: KASAN: use-after-free in mas_safe_min lib/maple_tree.c:721 [inline] BUG: KASAN: use-after-free in mas_next_nentry lib/maple_tree.c:4662 [inline] BUG: KASAN: use-after-free in mas_next_entry+0x344/0x10f0 lib/maple_tree.c:4757 Read of size 8 at addr ffff888021c02020 by task syz-executor.3/18219 CPU: 1 PID: 18219 Comm: syz-executor.3 Not tainted 6.1.0-rc2-syzkaller-00070-g4dc12f37a8e9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:284 print_report+0x107/0x220 mm/kasan/report.c:395 kasan_report+0x139/0x170 mm/kasan/report.c:495 mas_safe_min lib/maple_tree.c:721 [inline] mas_next_nentry lib/maple_tree.c:4662 [inline] mas_next_entry+0x344/0x10f0 lib/maple_tree.c:4757 userfaultfd_unregister+0x1240/0x13b0 fs/userfaultfd.c:1657 userfaultfd_ioctl+0x5a1/0x3230 fs/userfaultfd.c:2005 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f423508b5a9 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:00007f4235e8c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f42351abf80 RCX: 00007f423508b5a9 RDX: 0000000020000040 RSI: 000000008010aa01 RDI: 0000000000000003 RBP: 00007f42350e67b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff3d6edbef R14: 00007f4235e8c300 R15: 0000000000022000 Allocated by task 3644: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 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+0x43d/0x580 mm/slub.c:3854 mt_alloc_bulk lib/maple_tree.c:157 [inline] mas_alloc_nodes+0x386/0x650 lib/maple_tree.c:1256 mas_node_count_gfp lib/maple_tree.c:1316 [inline] mas_node_count lib/maple_tree.c:1330 [inline] mas_expected_entries+0x215/0x340 lib/maple_tree.c:5822 dup_mmap+0x5f6/0xff0 kernel/fork.c:613 dup_mm+0x8c/0x310 kernel/fork.c:1526 copy_mm+0xcb/0x160 kernel/fork.c:1575 copy_process+0x1973/0x3fc0 kernel/fork.c:2253 kernel_clone+0x227/0x640 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0x276/0x2e0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 18219: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free_bulk+0x137/0x1a0 mm/slub.c:3779 mt_free_bulk lib/maple_tree.c:163 [inline] mas_destroy+0x2d02/0x37b0 lib/maple_tree.c:5769 mas_store_prealloc+0x35d/0x450 lib/maple_tree.c:5704 vma_mas_store mm/mmap.c:435 [inline] __vma_adjust+0x162e/0x2120 mm/mmap.c:784 __split_vma+0x374/0x4f0 userfaultfd_unregister+0x1131/0x13b0 fs/userfaultfd.c:1636 userfaultfd_ioctl+0x5a1/0x3230 fs/userfaultfd.c:2005 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888021c02000 which belongs to the cache maple_node of size 256 The buggy address is located 32 bytes inside of 256-byte region [ffff888021c02000, ffff888021c02100) The buggy address belongs to the physical page: page:ffffea0000870080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21c02 head:ffffea0000870080 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801204fdc0 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 0x152800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 3644, tgid 3644 (syz-executor.3), ts 586179703272, free_ts 585832317955 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4287 __alloc_pages+0x259/0x560 mm/page_alloc.c:5554 alloc_slab_page+0x70/0xf0 mm/slub.c:1794 allocate_slab+0x5e/0x4b0 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0x7f4/0xeb0 mm/slub.c:3180 kmem_cache_alloc_bulk+0x1f1/0x580 mm/slub.c:3830 mt_alloc_bulk lib/maple_tree.c:157 [inline] mas_alloc_nodes+0x386/0x650 lib/maple_tree.c:1256 mas_node_count_gfp lib/maple_tree.c:1316 [inline] mas_node_count lib/maple_tree.c:1330 [inline] mas_expected_entries+0x215/0x340 lib/maple_tree.c:5822 dup_mmap+0x5f6/0xff0 kernel/fork.c:613 dup_mm+0x8c/0x310 kernel/fork.c:1526 copy_mm+0xcb/0x160 kernel/fork.c:1575 copy_process+0x1973/0x3fc0 kernel/fork.c:2253 kernel_clone+0x227/0x640 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0x276/0x2e0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 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+0x80c/0x8f0 mm/page_alloc.c:1508 free_unref_page_prepare mm/page_alloc.c:3386 [inline] free_unref_page+0x7d/0x630 mm/page_alloc.c:3482 qlist_free_all+0x2b/0x70 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x169/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x1cc/0x300 mm/slub.c:3422 getname_flags+0xb8/0x4e0 fs/namei.c:139 vfs_fstatat fs/stat.c:266 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat+0xe2/0x7b0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888021c01f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888021c01f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888021c02000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021c02080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021c02100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================