================================================================== BUG: KASAN: slab-use-after-free in handle_mm_fault+0x14f0/0x19a0 mm/memory.c:5842 Read of size 8 at addr ffff88802b7ab8d8 by task syz.0.780/7740 CPU: 0 UID: 0 PID: 7740 Comm: syz.0.780 Not tainted 6.10.0-rc7-next-20240712-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:5842 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0000:ffffc90004a2fad0 EFLAGS: 00050246 RAX: ffffffff84b11e01 RBX: 00000000201ac040 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffffc90004a2fb60 RDI: 00000000201ac000 RBP: ffffc90004a2fc10 R08: ffffc90004a2fb9f R09: 1ffff92000945f73 R10: dffffc0000000000 R11: fffff52000945f74 R12: 0000000000000040 R13: 0000000000178580 R14: 00000000201ac000 R15: ffffc90004a2fb60 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] _inline_copy_to_user include/linux/uaccess.h:181 [inline] _copy_to_user+0x86/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:209 [inline] rng_dev_read+0x3be/0x6d0 drivers/char/hw_random/core.c:251 do_loop_readv_writev fs/read_write.c:761 [inline] vfs_readv+0x6c2/0xa90 fs/read_write.c:934 do_preadv fs/read_write.c:1049 [inline] __do_sys_preadv fs/read_write.c:1099 [inline] __se_sys_preadv fs/read_write.c:1094 [inline] __x64_sys_preadv+0x1c7/0x2d0 fs/read_write.c:1094 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 RIP: 0033:0x7f9148575bd9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f91493f8048 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f9148703f60 RCX: 00007f9148575bd9 RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000004 RBP: 00007f91485e4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f9148703f60 R15: 00007ffda8f6f248 Allocated by task 7742: 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 7766: 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 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 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 remove_vma mm/mmap.c:189 [inline] remove_mt mm/mmap.c:2415 [inline] do_vmi_align_munmap+0x155c/0x18c0 mm/mmap.c:2758 do_vmi_munmap+0x261/0x2f0 mm/mmap.c:2830 mmap_region+0x72f/0x2090 mm/mmap.c:2881 do_mmap+0x8f9/0x1010 mm/mmap.c:1468 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 ksys_mmap_pgoff+0x544/0x720 mm/mmap.c:1514 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 The buggy address belongs to the object at ffff88802b7ab8b8 which belongs to the cache vm_area_struct of size 184 The buggy address is located 32 bytes inside of freed 184-byte region [ffff88802b7ab8b8, ffff88802b7ab970) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b7ab memcg:ffff88806d0e5201 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000000 ffff888015eefb40 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000100010 00000001fdffffff ffff88806d0e5201 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x152cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 7370, tgid 7370 (syz-executor), ts 178803577867, free_ts 178762652148 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2ccb/0x2d80 mm/page_alloc.c:3474 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4732 __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 7737 tgid 7737 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2692 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: ffff88802b7ab780: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88802b7ab800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc >ffff88802b7ab880: fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb ^ ffff88802b7ab900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff88802b7ab980: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 75 f1 jne 0xfffffff3 2: c3 ret 3: cc int3 4: cc int3 5: cc int3 6: cc int3 7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) e: 00 00 10: 48 8b 06 mov (%rsi),%rax 13: 48 89 07 mov %rax,(%rdi) 16: 48 83 c6 08 add $0x8,%rsi 1a: 48 83 c7 08 add $0x8,%rdi 1e: 83 e9 08 sub $0x8,%ecx 21: 74 df je 0x2 23: 83 f9 08 cmp $0x8,%ecx 26: 73 e8 jae 0x10 28: eb c9 jmp 0xfffffff3 * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 ret 2d: cc int3 2e: cc int3 2f: cc int3 30: cc int3 31: 48 89 c8 mov %rcx,%rax 34: 48 c1 e9 03 shr $0x3,%rcx 38: 83 e0 07 and $0x7,%eax 3b: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) 3e: 89 c1 mov %eax,%ecx