================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xc94/0xca0 fs/ext4/xattr.c:2902 Read of size 4 at addr ffff88812f21c000 by task syz-executor/439 CPU: 0 PID: 439 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 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+0xc94/0xca0 fs/ext4/xattr.c:2902 ext4_evict_inode+0xe50/0x1460 fs/ext4/inode.c:300 evict+0x4c9/0x8d0 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:4170 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_unlinkat fs/namei.c:4398 [inline] __se_sys_unlinkat fs/namei.c:4392 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4392 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: 0033:0x7fbdb5246d07 Code: 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe0badd7c8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007fbdb5246d07 RDX: 0000000000000200 RSI: 00007ffe0bade970 RDI: 00000000ffffff9c RBP: 00007fbdb52ca952 R08: 0000000000008680 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffe0bade970 R13: 00007fbdb52ca952 R14: 000000000000b315 R15: 00007ffe0bae0b20 Allocated by task 386: 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 vm_area_alloc+0x24/0x130 kernel/fork.c:360 __mmap_region mm/mmap.c:1794 [inline] mmap_region+0xaa6/0x1710 mm/mmap.c:2959 do_mmap+0x812/0xf10 mm/mmap.c:1598 vm_mmap_pgoff+0x1ec/0x430 mm/util.c:555 ksys_mmap_pgoff+0xf6/0x1d0 mm/mmap.c:1647 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10 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 419: 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 __free_vm_area_struct+0x1c/0x20 kernel/fork.c:390 rcu_do_batch+0x532/0xbe0 kernel/rcu/tree.c:2523 rcu_core+0x5ee/0xf80 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 __do_softirq+0xb/0xd kernel/softirq.c:621 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x10b/0xf80 kernel/rcu/tree.c:3129 free_vm_area_struct kernel/fork.c:395 [inline] vm_area_free_no_check+0x10e/0x140 kernel/fork.c:409 vm_area_free+0x56/0x60 kernel/fork.c:419 __vma_adjust+0x117b/0x1850 mm/mmap.c:973 vma_merge+0x3e6/0x910 mm/mmap.c:1250 mprotect_fixup+0x3f2/0x7d0 mm/mprotect.c:472 do_mprotect_pkey+0x72b/0xad0 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 ffff88812f21c000 which belongs to the cache vm_area_struct of size 232 The buggy address is located 0 bytes inside of 232-byte region [ffff88812f21c000, ffff88812f21c0e8) The buggy address belongs to the page: page:ffffea0004bc8700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12f21c flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100186000 raw: 0000000000000000 00000000000d000d 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 386, ts 45909069232, free_ts 45903703782 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+0x2d3a/0x2dc0 mm/page_alloc.c:4485 __alloc_pages+0x1a2/0x460 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 vm_area_alloc+0x24/0x130 kernel/fork.c:360 __mmap_region mm/mmap.c:1794 [inline] mmap_region+0xaa6/0x1710 mm/mmap.c:2959 do_mmap+0x812/0xf10 mm/mmap.c:1598 vm_mmap_pgoff+0x1ec/0x430 mm/util.c:555 ksys_mmap_pgoff+0xf6/0x1d0 mm/mmap.c:1647 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10 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+0xae/0x540 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5884 free_pages+0x82/0x90 mm/page_alloc.c:5895 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1381 inode_doinit_with_dentry+0x87a/0xd80 security/selinux/hooks.c:1576 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6495 security_d_instantiate+0x9e/0xf0 security/security.c:2074 d_splice_alias+0x6d/0x390 fs/dcache.c:3073 kernfs_iop_lookup+0x2c2/0x310 fs/kernfs/dir.c:1175 __lookup_slow+0x2b8/0x410 fs/namei.c:1671 lookup_slow+0x57/0x70 fs/namei.c:1688 walk_component+0x325/0x460 fs/namei.c:1984 lookup_last fs/namei.c:2439 [inline] path_lookupat+0x180/0x490 fs/namei.c:2463 filename_lookup+0x214/0x540 fs/namei.c:2492 user_path_at_empty+0x47/0x1c0 fs/namei.c:2891 Memory state around the buggy address: ffff88812f21bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88812f21bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88812f21c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88812f21c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88812f21c100: fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb ==================================================================