================================================================== BUG: KASAN: slab-use-after-free in madvise_collapse+0xa6c/0xb50 mm/khugepaged.c:2723 Read of size 8 at addr ffff888080f18988 by task syz-executor.1/9260 CPU: 1 PID: 9260 Comm: syz-executor.1 Not tainted 6.5.0-rc2-next-20230721-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 madvise_collapse+0xa6c/0xb50 mm/khugepaged.c:2723 madvise_vma_behavior+0x200/0x1e60 mm/madvise.c:1094 madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1268 do_madvise+0x333/0x660 mm/madvise.c:1448 __do_sys_madvise mm/madvise.c:1461 [inline] __se_sys_madvise mm/madvise.c:1459 [inline] __x64_sys_madvise+0xaa/0x110 mm/madvise.c:1459 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0b57c7cb29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0b58a890c8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f0b57d9c050 RCX: 00007f0b57c7cb29 RDX: 0000000000000019 RSI: 000000000060005f RDI: 0000000020000000 RBP: 00007f0b57cc847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f0b57d9c050 R15: 00007fffadca8bc8 Allocated by task 9220: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:762 [inline] slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x172/0x3b0 mm/slub.c:3502 vm_area_alloc+0x1f/0x220 kernel/fork.c:485 mmap_region+0x386/0x2640 mm/mmap.c:2717 do_mmap+0x87c/0xed0 mm/mmap.c:1353 vm_mmap_pgoff+0x1a6/0x3b0 mm/util.c:543 ksys_mmap_pgoff+0x7d/0x5b0 mm/mmap.c:1399 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 15: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15e/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] kmem_cache_free+0xf0/0x490 mm/slub.c:3831 rcu_do_batch kernel/rcu/tree.c:2139 [inline] rcu_core+0x7fb/0x1bb0 kernel/rcu/tree.c:2403 __do_softirq+0x218/0x965 kernel/softirq.c:553 Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653 vma_complete+0x856/0xdf0 mm/mmap.c:583 vma_merge+0x9f1/0x15f0 mm/mmap.c:1015 userfaultfd_release+0x3d7/0x7c0 fs/userfaultfd.c:926 __fput+0x3fd/0xac0 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:179 get_signal+0x106f/0x27b0 kernel/signal.c:2664 arch_do_signal_or_restart+0x89/0x5f0 arch/x86/kernel/signal.c:308 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2653 remove_vma+0x140/0x170 mm/mmap.c:148 remove_mt mm/mmap.c:2285 [inline] do_vmi_align_munmap+0xf75/0x1710 mm/mmap.c:2547 do_vmi_munmap+0x20e/0x450 mm/mmap.c:2611 mmap_region+0x194/0x2640 mm/mmap.c:2661 do_mmap+0x87c/0xed0 mm/mmap.c:1353 vm_mmap_pgoff+0x1a6/0x3b0 mm/util.c:543 ksys_mmap_pgoff+0x422/0x5b0 mm/mmap.c:1399 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888080f18900 which belongs to the cache vm_area_struct of size 192 The buggy address is located 136 bytes inside of freed 192-byte region [ffff888080f18900, ffff888080f189c0) The buggy address belongs to the physical page: page:ffffea000203c600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x80f18 memcg:ffff888022941901 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000200 ffff888014674b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000001ffffffff ffff888022941901 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 6626, tgid 6626 (syz-executor.4), ts 454299774736, free_ts 443564498328 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1569 prep_new_page mm/page_alloc.c:1576 [inline] get_page_from_freelist+0x10d7/0x31b0 mm/page_alloc.c:3256 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4512 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab+0x24e/0x380 mm/slub.c:2017 new_slab mm/slub.c:2070 [inline] ___slab_alloc+0x8bc/0x1570 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x392/0x3b0 mm/slub.c:3502 vm_area_dup+0x21/0x2f0 kernel/fork.c:500 dup_mmap+0x93c/0x1d80 kernel/fork.c:710 dup_mm kernel/fork.c:1697 [inline] copy_mm kernel/fork.c:1746 [inline] copy_process+0x6c11/0x7400 kernel/fork.c:2512 kernel_clone+0xfd/0x930 kernel/fork.c:2920 __do_sys_clone+0xba/0x100 kernel/fork.c:3063 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 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:1160 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2383 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2478 vfree+0x181/0x7a0 mm/vmalloc.c:2842 kcov_put kernel/kcov.c:429 [inline] kcov_put+0x26/0x40 kernel/kcov.c:425 kcov_close+0x10/0x20 kernel/kcov.c:525 __fput+0x3fd/0xac0 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa99/0x2a20 kernel/exit.c:874 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888080f18880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff888080f18900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888080f18980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888080f18a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888080f18a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================