================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 Read of size 4 at addr ffff88811ac55000 by task syz-executor/452 CPU: 0 PID: 452 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 ext4_evict_inode+0xe44/0x1450 fs/ext4/inode.c:300 evict+0x485/0x870 fs/inode.c:650 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 d_delete_notify include/linux/fsnotify.h:278 [inline] vfs_rmdir+0x33f/0x460 fs/namei.c:4162 do_rmdir+0x259/0x6a0 fs/namei.c:4210 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4384 x64_sys_call+0x4c0/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f86e8e6fcf7 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 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:00007ffe2a0b14f8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f86e8e6fcf7 RDX: 0000000000000200 RSI: 00007ffe2a0b26a0 RDI: 00000000ffffff9c RBP: 00007f86e8ee31cc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffe2a0b26a0 R13: 00007f86e8ee31cc R14: 000000000000c656 R15: 00007ffe2a0b4850 Allocated by task 165: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 anon_vma_chain_alloc mm/rmap.c:141 [inline] anon_vma_fork+0x200/0x510 mm/rmap.c:363 dup_mmap kernel/fork.c:619 [inline] dup_mm kernel/fork.c:1522 [inline] copy_mm+0x9d1/0x13a0 kernel/fork.c:1574 copy_process+0x115c/0x3210 kernel/fork.c:2348 kernel_clone+0x23f/0x940 kernel/fork.c:2737 __do_sys_clone kernel/fork.c:2863 [inline] __se_sys_clone kernel/fork.c:2847 [inline] __x64_sys_clone+0x176/0x1d0 kernel/fork.c:2847 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 169: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3544 anon_vma_chain_free mm/rmap.c:146 [inline] unlink_anon_vmas+0x55f/0x590 mm/rmap.c:448 free_pgtables+0x131/0x280 mm/memory.c:489 exit_mmap+0x407/0x860 mm/mmap.c:3247 __mmput+0x93/0x320 kernel/fork.c:1180 mmput+0x50/0x150 kernel/fork.c:1203 exec_mmap+0x422/0x4e0 fs/exec.c:1047 begin_new_exec+0xa8b/0x1ea0 fs/exec.c:1306 load_elf_binary+0x98e/0x2890 fs/binfmt_elf.c:1001 search_binary_handler fs/exec.c:1755 [inline] exec_binprm fs/exec.c:1796 [inline] bprm_execve+0x795/0x1480 fs/exec.c:1865 do_execveat_common+0x923/0xa80 fs/exec.c:1970 do_execve fs/exec.c:2040 [inline] __do_sys_execve fs/exec.c:2116 [inline] __se_sys_execve fs/exec.c:2111 [inline] __x64_sys_execve+0x92/0xb0 fs/exec.c:2111 x64_sys_call+0x919/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:60 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88811ac55000 which belongs to the cache anon_vma_chain of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff88811ac55000, ffff88811ac55040) The buggy address belongs to the page: page:ffffea00046b1540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ac55 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100187080 raw: 0000000000000000 00000000002a002a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY), pid 165, ts 6816466642, free_ts 6779543305 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5808 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3260 anon_vma_chain_alloc mm/rmap.c:141 [inline] anon_vma_clone+0xc0/0x500 mm/rmap.c:287 anon_vma_fork+0x8c/0x510 mm/rmap.c:350 dup_mmap kernel/fork.c:619 [inline] dup_mm kernel/fork.c:1522 [inline] copy_mm+0x9d1/0x13a0 kernel/fork.c:1574 copy_process+0x115c/0x3210 kernel/fork.c:2348 kernel_clone+0x23f/0x940 kernel/fork.c:2737 __do_sys_clone kernel/fork.c:2863 [inline] __se_sys_clone kernel/fork.c:2847 [inline] __x64_sys_clone+0x176/0x1d0 kernel/fork.c:2847 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page_list+0x134/0x9d0 mm/page_alloc.c:3671 release_pages+0xfda/0x1030 mm/swap.c:1014 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x175/0x300 mm/mmu_gather.c:338 exit_mmap+0x40f/0x860 mm/mmap.c:3248 __mmput+0x93/0x320 kernel/fork.c:1180 mmput+0x50/0x150 kernel/fork.c:1203 exit_mm kernel/exit.c:554 [inline] do_exit+0x9d2/0x27a0 kernel/exit.c:876 do_group_exit+0x141/0x310 kernel/exit.c:1003 __do_sys_exit_group kernel/exit.c:1014 [inline] __se_sys_exit_group kernel/exit.c:1012 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012 x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff88811ac54f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811ac54f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811ac55000: fa fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb ^ ffff88811ac55080: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb ffff88811ac55100: fc fc fc fc fa fb fb fb fb fb fb fb fc fc fc fc ==================================================================