================================================================== 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 ffff888048e40e20 by task syz-executor.2/12246 CPU: 1 PID: 12246 Comm: syz-executor.2 Not tainted 6.1.0-rc2-syzkaller-00078-g98555239e4c3 #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+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d 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: 0033:0x7fea86a8b5a9 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:00007fea87890168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fea86bac050 RCX: 00007fea86a8b5a9 RDX: 0000000020000100 RSI: 000000008010aa01 RDI: 0000000000000003 RBP: 00007fea86ae67b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fea86ccfb1f R14: 00007fea87890300 R15: 0000000000022000 Allocated by task 3659: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7e/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+0x3e9/0x830 mm/slub.c:3854 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 12246: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2a/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free_bulk.part.0+0x205/0x780 mm/slub.c:3779 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+0xc66/0x1ae0 mm/mmap.c:784 vma_adjust include/linux/mm.h:2663 [inline] __split_vma+0x4b0/0x5c0 mm/mmap.c:2237 split_vma+0x9f/0xe0 mm/mmap.c:2273 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 ffff888048e40e00 which belongs to the cache maple_node of size 256 The buggy address is located 32 bytes inside of 256-byte region [ffff888048e40e00, ffff888048e40f00) The buggy address belongs to the physical page: page:ffffea0001239000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x48e40 head:ffffea0001239000 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88801184fdc0 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 3659, tgid 3659 (syz-executor.2), ts 313095364345, free_ts 311238017004 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+0x1a6/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x312/0x3c0 mm/slub.c:3422 mt_alloc_one lib/maple_tree.c:152 [inline] mas_alloc_nodes+0x429/0x810 lib/maple_tree.c:1231 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 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 __vunmap+0x85d/0xd30 mm/vmalloc.c:2713 __vfree+0x3c/0xd0 mm/vmalloc.c:2761 vfree+0x5a/0x90 mm/vmalloc.c:2792 snd_dma_free_pages+0xcc/0x120 sound/core/memalloc.c:126 do_free_pages sound/core/pcm_memory.c:65 [inline] do_free_pages sound/core/pcm_memory.c:57 [inline] snd_pcm_lib_free_pages+0x20f/0x450 sound/core/pcm_memory.c:471 do_hw_free sound/core/pcm_native.c:876 [inline] snd_pcm_release_substream.part.0+0x29d/0x330 sound/core/pcm_native.c:2705 snd_pcm_release_substream+0x57/0x70 sound/core/pcm_native.c:2699 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2413 [inline] snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2405 [inline] snd_pcm_oss_release+0x171/0x300 sound/core/oss/pcm_oss.c:2592 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16b/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb35/0x2a20 kernel/exit.c:820 do_group_exit+0xd0/0x2a0 kernel/exit.c:950 get_signal+0x21a1/0x2430 kernel/signal.c:2858 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 Memory state around the buggy address: ffff888048e40d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888048e40d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888048e40e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888048e40e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888048e40f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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