================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909 Read of size 4 at addr ffff888114dd0000 by task syz-executor/477 CPU: 0 PID: 477 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+0x21/0x24 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+0x10d3/0x1760 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: 0033:0x7fbcf5b69887 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:00007fff9b025ea8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007fbcf5b69887 RDX: 0000000000000200 RSI: 00007fff9b027050 RDI: 00000000ffffff9c RBP: 00007fbcf5bc66c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007fff9b027050 R13: 00007fbcf5bc66c6 R14: 000000000000a4fc R15: 0000000000000007 Allocated by task 435: 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_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1a7/0x330 mm/slub.c:4038 __kmalloc_node include/linux/slab.h:418 [inline] kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x88/0x130 mm/util.c:612 kvmalloc include/linux/mm.h:833 [inline] seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x1fc/0xd30 fs/seq_file.c:210 kernfs_fop_read_iter+0x147/0x470 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2060 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x874/0xa10 fs/read_write.c:496 ksys_read+0x140/0x240 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:642 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 435: 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:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 kvfree+0x35/0x40 mm/util.c:647 seq_release+0x57/0x70 fs/seq_file.c:355 kernfs_fop_release+0x1af/0x250 fs/kernfs/file.c:761 __fput+0x2fb/0x770 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888114dd0000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff888114dd0000, ffff888114dd1000) The buggy address belongs to the page: page:ffffea0004537400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x114dd0 head:ffffea0004537400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042c00 raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 102, ts 5033479932, free_ts 0 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:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc_trace+0x1b3/0x2e0 mm/slub.c:2977 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] uevent_show+0x160/0x330 drivers/base/core.c:2295 dev_attr_show+0x56/0xd0 drivers/base/core.c:2002 sysfs_kf_seq_show+0x266/0x3d0 fs/sysfs/file.c:61 kernfs_seq_show+0x119/0x160 fs/kernfs/file.c:168 seq_read_iter+0x490/0xd30 fs/seq_file.c:230 kernfs_fop_read_iter+0x147/0x470 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2060 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x874/0xa10 fs/read_write.c:496 ksys_read+0x140/0x240 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:642 page_owner free stack trace missing Memory state around the buggy address: ffff888114dcff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888114dcff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888114dd0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888114dd0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888114dd0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================