================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 Read of size 4 at addr ffff88811cfac000 by task syz-executor/456 CPU: 0 PID: 456 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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: 0033:0x7f8aa0040cf7 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:00007ffeeec24e68 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f8aa0040cf7 RDX: 0000000000000200 RSI: 00007ffeeec26010 RDI: 00000000ffffff9c RBP: 00007f8aa00b423c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffeeec26010 R13: 00007f8aa00b423c R14: 000000000000c06f R15: 00007ffeeec281c0 Allocated by task 398: 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:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255 anon_vma_chain_alloc mm/rmap.c:141 [inline] __anon_vma_prepare+0x56/0x420 mm/rmap.c:195 do_anonymous_page mm/memory.c:4066 [inline] handle_pte_fault+0x1f08/0x2680 mm/memory.c:4909 __handle_mm_fault mm/memory.c:-1 [inline] do_handle_mm_fault+0x1a6d/0x1d50 mm/memory.c:5333 handle_mm_fault include/linux/mm.h:1836 [inline] do_user_addr_fault+0x841/0x1180 arch/x86/mm/fault.c:1418 handle_page_fault arch/x86/mm/fault.c:1509 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1565 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606 Freed by task 398: 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:1723 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749 slab_free mm/slub.c:3521 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3539 anon_vma_chain_free mm/rmap.c:146 [inline] unlink_anon_vmas+0x2ce/0x590 mm/rmap.c:420 anon_vma_merge include/linux/rmap.h:178 [inline] __vma_adjust+0x10d3/0x17b0 mm/mmap.c:969 vma_merge+0x3e6/0x910 mm/mmap.c:1249 mprotect_fixup+0x3ee/0x7d0 mm/mprotect.c:472 do_mprotect_pkey+0x70b/0xa80 mm/mprotect.c:646 __do_sys_mprotect mm/mprotect.c:673 [inline] __se_sys_mprotect mm/mprotect.c:670 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:670 x64_sys_call+0x912/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:11 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 ffff88811cfac000 which belongs to the cache anon_vma_chain of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff88811cfac000, ffff88811cfac040) The buggy address belongs to the page: page:ffffea000473eb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11cfac flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100186180 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 398, ts 49344375381, free_ts 49216116524 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:5795 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1932 [inline] new_slab+0xa1/0x4d0 mm/slub.c:1995 ___slab_alloc+0x381/0x810 mm/slub.c:3028 __slab_alloc+0x49/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3255 anon_vma_chain_alloc mm/rmap.c:141 [inline] __anon_vma_prepare+0x56/0x420 mm/rmap.c:195 do_anonymous_page mm/memory.c:4066 [inline] handle_pte_fault+0x1f08/0x2680 mm/memory.c:4909 __handle_mm_fault mm/memory.c:-1 [inline] do_handle_mm_fault+0x1a6d/0x1d50 mm/memory.c:5333 handle_mm_fault include/linux/mm.h:1836 [inline] do_user_addr_fault+0x841/0x1180 arch/x86/mm/fault.c:1418 handle_page_fault arch/x86/mm/fault.c:1509 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1565 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606 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 __pagevec_release+0x71/0xe0 mm/swap.c:1034 pagevec_release include/linux/pagevec.h:81 [inline] __invalidate_mapping_pages+0x45a/0x610 mm/truncate.c:517 invalidate_mapping_pages+0x27/0x30 mm/truncate.c:541 invalidate_bdev+0xa6/0x150 block/bdev.c:88 ext4_put_super+0x6cb/0xa70 fs/ext4/super.c:1247 generic_shutdown_super+0x151/0x330 fs/super.c:475 kill_block_super+0x7f/0xf0 fs/super.c:1427 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1139 __cleanup_mnt+0x19/0x20 fs/namespace.c:1146 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 Memory state around the buggy address: ffff88811cfabf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811cfabf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811cfac000: fa fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb ^ ffff88811cfac080: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb ffff88811cfac100: fc fc fc fc fa fb fb fb fb fb fb fb fc fc fc fc ==================================================================