================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909 Read of size 4 at addr ffff8881148ea000 by task syz-executor/467 CPU: 0 PID: 467 Comm: syz-executor Not tainted 5.10.240-syzkaller-1008073-gad9a98ef27a4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909 ext4_evict_inode+0x106f/0x16e0 fs/ext4/inode.c:300 evict+0x478/0x910 fs/inode.c:612 iput_final fs/inode.c:1736 [inline] iput+0x638/0x7c0 fs/inode.c:1762 d_delete_notify include/linux/fsnotify.h:267 [inline] vfs_rmdir+0x2bd/0x3e0 fs/namei.c:3865 do_rmdir+0x218/0x620 fs/namei.c:3912 __do_sys_unlinkat fs/namei.c:4076 [inline] __se_sys_unlinkat fs/namei.c:4070 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9269382887 Code: 73 01 c3 48 c7 c1 b0 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdc66a46b8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f9269382887 RDX: 0000000000000200 RSI: 00007ffdc66a5860 RDI: 00000000ffffff9c RBP: 00007f92693df6c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffdc66a5860 R13: 00007f92693df6c6 R14: 000000000000bfea R15: 0000000000000000 Allocated by task 100: 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:430 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583 slab_alloc_node mm/slub.c:2947 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960 kmem_cache_zalloc include/linux/slab.h:654 [inline] seq_open+0x61/0x130 fs/seq_file.c:63 kernfs_fop_open+0x4da/0xb30 fs/kernfs/file.c:-1 do_dentry_open+0x793/0x1090 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x27ad/0x3160 fs/namei.c:3509 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1244 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8881148ea000 which belongs to the cache seq_file of size 136 The buggy address is located 0 bytes inside of 136-byte region [ffff8881148ea000, ffff8881148ea088) The buggy address belongs to the page: page:ffffea0004523a80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881148ea640 pfn:0x1148ea flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea0004523900 0000000800000008 ffff88810018b500 raw: ffff8881148ea640 0000000080140000 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 100, ts 5555880351, free_ts 5555824744 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5357 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x84/0x3f0 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960 kmem_cache_zalloc include/linux/slab.h:654 [inline] seq_open+0x61/0x130 fs/seq_file.c:63 kernfs_fop_open+0x4da/0xb30 fs/kernfs/file.c:-1 do_dentry_open+0x793/0x1090 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x27ad/0x3160 fs/namei.c:3509 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1244 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page mm/page_alloc.c:5416 [inline] __free_pages+0x14b/0x380 mm/page_alloc.c:5427 free_pages+0x82/0x90 mm/page_alloc.c:5438 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1326 inode_doinit_with_dentry+0x86d/0xd70 security/selinux/hooks.c:1523 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6389 security_d_instantiate+0x9e/0xf0 security/security.c:1980 d_splice_alias+0x6d/0x390 fs/dcache.c:3036 kernfs_iop_lookup+0x2c5/0x310 fs/kernfs/dir.c:1178 __lookup_slow+0x2aa/0x3e0 fs/namei.c:1640 lookup_slow+0x57/0x70 fs/namei.c:1657 walk_component+0x325/0x460 fs/namei.c:1952 lookup_last fs/namei.c:2403 [inline] path_lookupat+0x180/0x490 fs/namei.c:2427 filename_lookup+0x1d5/0x600 fs/namei.c:2460 user_path_at_empty+0x43/0x50 fs/namei.c:2740 user_path_at include/linux/namei.h:60 [inline] vfs_statx+0xff/0x520 fs/stat.c:193 Memory state around the buggy address: ffff8881148e9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881148e9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881148ea000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881148ea080: fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb ffff8881148ea100: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ==================================================================