================================================================== 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 ffff88807c33a620 by task syz-executor.3/6173 CPU: 0 PID: 6173 Comm: syz-executor.3 Not tainted 6.1.0-rc3-syzkaller-00158-gee6050c8af96 #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+0x1251/0x13c0 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: 0033:0x7f154508b5a9 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:00007f15443de168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f15451ac120 RCX: 00007f154508b5a9 RDX: 00000000200000c0 RSI: 000000008010aa01 RDI: 0000000000000004 RBP: 00007f15450e67b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa266454f R14: 00007f15443de300 R15: 0000000000022000 Allocated by task 6163: 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_preallocate+0x133/0x340 lib/maple_tree.c:5719 __vma_adjust+0x886/0x2120 mm/mmap.c:716 __split_vma+0x374/0x4f0 mprotect_fixup+0x538/0x820 mm/mprotect.c:617 do_mprotect_pkey+0x7fc/0xb20 mm/mprotect.c:792 __do_sys_mprotect mm/mprotect.c:819 [inline] __se_sys_mprotect mm/mprotect.c:816 [inline] __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:816 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 6173: 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+0x114d/0x13c0 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 ffff88807c33a600 which belongs to the cache maple_node of size 256 The buggy address is located 32 bytes inside of 256-byte region [ffff88807c33a600, ffff88807c33a700) The buggy address belongs to the physical page: page:ffffea0001f0ce80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c33a head:ffffea0001f0ce80 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d41100 dead000000000002 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3189, tgid 3189 (dhcpcd), ts 26379290883, free_ts 24862349469 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4288 __alloc_pages+0x259/0x560 mm/page_alloc.c:5555 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_preallocate+0x133/0x340 lib/maple_tree.c:5719 __vma_adjust+0x886/0x2120 mm/mmap.c:716 __split_vma+0x374/0x4f0 mprotect_fixup+0x5d1/0x820 mm/mprotect.c:623 do_mprotect_pkey+0x7fc/0xb20 mm/mprotect.c:792 __do_sys_mprotect mm/mprotect.c:819 [inline] __se_sys_mprotect mm/mprotect.c:816 [inline] __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:816 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:1459 [inline] free_pcp_prepare+0x80c/0x8f0 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x7d/0x630 mm/page_alloc.c:3483 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_lru+0x180/0x2e0 mm/slub.c:3429 alloc_inode_sb include/linux/fs.h:3117 [inline] shmem_alloc_inode+0x21/0x40 mm/shmem.c:3853 alloc_inode fs/inode.c:259 [inline] new_inode_pseudo+0x61/0x1d0 fs/inode.c:1018 new_inode+0x25/0x1d0 fs/inode.c:1046 shmem_get_inode+0x321/0xc30 mm/shmem.c:2329 shmem_mknod+0x54/0x1b0 mm/shmem.c:2910 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12e2/0x2e00 fs/namei.c:3710 do_filp_open+0x275/0x500 fs/namei.c:3740 do_sys_openat2+0x13b/0x500 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 Memory state around the buggy address: ffff88807c33a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807c33a580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807c33a600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c33a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c33a700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================