================================================================== BUG: KASAN: slab-use-after-free in do_sync_mmap_readahead+0x4bf/0x830 mm/filemap.c:3282 Read of size 8 at addr ffff888078d2a690 by task syz.0.1017/9157 CPU: 0 UID: 0 PID: 9157 Comm: syz.0.1017 Not tainted 6.16.0-rc2-next-20250620-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 do_sync_mmap_readahead+0x4bf/0x830 mm/filemap.c:3282 filemap_fault+0x62c/0x1200 mm/filemap.c:3444 __do_fault+0x138/0x390 mm/memory.c:5187 do_read_fault mm/memory.c:5608 [inline] do_fault mm/memory.c:5742 [inline] do_pte_missing mm/memory.c:4269 [inline] handle_pte_fault mm/memory.c:6087 [inline] __handle_mm_fault+0x37ed/0x5620 mm/memory.c:6230 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6399 faultin_page mm/gup.c:1186 [inline] __get_user_pages+0x1aef/0x30b0 mm/gup.c:1488 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1922 __mm_populate+0x24c/0x380 mm/gup.c:2025 do_mlock+0x625/0x740 mm/mlock.c:655 __do_sys_mlock mm/mlock.c:663 [inline] __se_sys_mlock mm/mlock.c:661 [inline] __x64_sys_mlock+0x60/0x70 mm/mlock.c:661 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe767d8e929 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:00007fe768c09038 EFLAGS: 00000246 ORIG_RAX: 0000000000000095 RAX: ffffffffffffffda RBX: 00007fe767fb6240 RCX: 00007fe767d8e929 RDX: 0000000000000000 RSI: 0000000000800000 RDI: 0000200000000000 RBP: 00007fe767e10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe767fb6240 R15: 00007fff16e93f08 Allocated by task 9156: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4179 [inline] slab_alloc_node mm/slub.c:4228 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4235 vm_area_alloc+0x24/0x140 mm/vma_init.c:31 __mmap_new_vma mm/vma.c:2466 [inline] __mmap_region mm/vma.c:2676 [inline] mmap_region+0xe0d/0x2080 mm/vma.c:2746 do_mmap+0xc45/0x10d0 mm/mmap.c:561 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 1108: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2416 [inline] slab_free_after_rcu_debug+0x129/0x2a0 mm/slub.c:4729 rcu_do_batch kernel/rcu/tree.c:2582 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2838 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2377 [inline] slab_free mm/slub.c:4679 [inline] kmem_cache_free+0x2f6/0x400 mm/slub.c:4781 remove_vma mm/vma.c:449 [inline] vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1273 __mmap_complete mm/vma.c:2532 [inline] __mmap_region mm/vma.c:2684 [inline] mmap_region+0x1221/0x2080 mm/vma.c:2746 do_mmap+0xc45/0x10d0 mm/mmap.c:561 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579 ksys_mmap_pgoff+0x587/0x760 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888078d2a640 which belongs to the cache vm_area_struct of size 256 The buggy address is located 80 bytes inside of freed 256-byte region [ffff888078d2a640, ffff888078d2a740) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78d2a memcg:ffff888078d05601 ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801bad4b40 ffffea0001f70940 dead000000000003 raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff888078d05601 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 5735, tgid 5735 (cmp), ts 71468360489, free_ts 27878803902 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2486 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2654 new_slab mm/slub.c:2708 [inline] ___slab_alloc+0xbeb/0x1410 mm/slub.c:3890 __slab_alloc mm/slub.c:3980 [inline] __slab_alloc_node mm/slub.c:4055 [inline] slab_alloc_node mm/slub.c:4216 [inline] kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4235 vm_area_dup+0x2b/0x680 mm/vma_init.c:122 __split_vma+0x1a9/0xa00 mm/vma.c:496 vms_gather_munmap_vmas+0x2de/0x12b0 mm/vma.c:1339 __mmap_prepare mm/vma.c:2365 [inline] __mmap_region mm/vma.c:2655 [inline] mmap_region+0x71a/0x2080 mm/vma.c:2746 do_mmap+0xc45/0x10d0 mm/mmap.c:561 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 __free_pages mm/page_alloc.c:5071 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:6927 destroy_args+0x7e/0x5d0 mm/debug_vm_pgtable.c:1009 debug_vm_pgtable+0x412/0x450 mm/debug_vm_pgtable.c:1389 do_one_initcall+0x233/0x820 init/main.c:1274 do_initcall_level+0x137/0x1f0 init/main.c:1336 do_initcalls+0x69/0xd0 init/main.c:1352 kernel_init_freeable+0x3d9/0x570 init/main.c:1584 kernel_init+0x1d/0x1d0 init/main.c:1474 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888078d2a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078d2a600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff888078d2a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078d2a700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888078d2a780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================