================================================================== BUG: KASAN: slab-use-after-free in handle_mm_fault+0x14f0/0x19a0 mm/memory.c:5835 Read of size 8 at addr ffff88802bf87cb8 by task syz.4.467/6916 CPU: 1 UID: 0 PID: 6916 Comm: syz.4.467 Not tainted 6.10.0-next-20240717-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 handle_mm_fault+0x14f0/0x19a0 mm/memory.c:5835 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f172103911e Code: e9 5d fe ff ff 0f 1f 80 00 00 00 00 48 89 7c 24 f0 48 89 74 24 e8 48 89 54 24 e0 48 8b 4c 24 f0 48 8b 54 24 e8 48 8b 74 24 e0 <8b> 41 40 23 81 00 01 00 00 f3 0f 6f 06 c1 e0 06 48 01 d0 0f 11 00 RSP: 002b:00007f1721e85038 EFLAGS: 00010212 RAX: 00007f1721039100 RBX: 00007f1721303f60 RCX: 0000000020400000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020400000 RBP: 00007f17211e4e5d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020400000 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000000000b R14: 00007f1721303f60 R15: 00007ffc16991e58 Allocated by task 6916: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472 mmap_region+0xc3d/0x2090 mm/mmap.c:2944 do_mmap+0x8f9/0x1010 mm/mmap.c:1468 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 24: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kmem_cache_free+0x145/0x350 mm/slub.c:4548 rcu_do_batch kernel/rcu/tree.c:2569 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2843 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:928 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 __call_rcu_common kernel/rcu/tree.c:3106 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3210 vma_complete+0x98a/0xb60 mm/mmap.c:609 vma_merge+0x1d9b/0x2690 mm/mmap.c:1079 vma_modify+0xb8/0x350 mm/mmap.c:2565 vma_modify_flags_uffd include/linux/mm.h:3352 [inline] userfaultfd_release+0x413/0x900 fs/userfaultfd.c:907 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802bf87c98 which belongs to the cache vm_area_struct of size 184 The buggy address is located 32 bytes inside of freed 184-byte region [ffff88802bf87c98, ffff88802bf87d50) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bf87 memcg:ffff88807c83fe01 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000000 ffff888015eefb40 ffffea0000b99d00 dead000000000008 raw: 0000000000000000 0000000000100010 00000001fdffffff ffff88807c83fe01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5089, tgid 5089 (sshd), ts 77694251111, free_ts 72356008215 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1492 prep_new_page mm/page_alloc.c:1500 [inline] get_page_from_freelist+0x2ccb/0x2d80 mm/page_alloc.c:3473 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4731 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2321 allocate_slab+0x5a/0x2f0 mm/slub.c:2484 new_slab mm/slub.c:2537 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723 __slab_alloc+0x58/0xa0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4044 vm_area_dup+0x27/0x290 kernel/fork.c:487 dup_mmap kernel/fork.c:696 [inline] dup_mm kernel/fork.c:1674 [inline] copy_mm+0xc7b/0x1f30 kernel/fork.c:1723 copy_process+0x186b/0x3d90 kernel/fork.c:2376 kernel_clone+0x226/0x8f0 kernel/fork.c:2788 __do_sys_clone kernel/fork.c:2931 [inline] __se_sys_clone kernel/fork.c:2915 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2915 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5023 tgid 5023 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1093 [inline] free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2691 folios_put_refs+0x76e/0x860 mm/swap.c:1039 free_pages_and_swap_cache+0x5c8/0x690 mm/swap_state.c:335 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:373 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:465 exit_mmap+0x44f/0xc80 mm/mmap.c:3425 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88802bf87b80: fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802bf87c00: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >ffff88802bf87c80: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802bf87d00: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff88802bf87d80: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================