================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xc67/0xc80 fs/ext4/xattr.c:2900 Read of size 4 at addr ffff88810eb23000 by task syz-executor/499 CPU: 1 PID: 499 Comm: syz-executor Not tainted 5.10.234-syzkaller-1006684-g094fc3778d6b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xc67/0xc80 fs/ext4/xattr.c:2900 ext4_evict_inode+0x1095/0x1730 fs/ext4/inode.c:300 evict+0x526/0x9c0 fs/inode.c:612 iput_final fs/inode.c:1736 [inline] iput+0x632/0x7e0 fs/inode.c:1762 d_delete_notify include/linux/fsnotify.h:267 [inline] vfs_rmdir+0x271/0x3f0 fs/namei.c:3865 do_rmdir+0x2cf/0x5c0 fs/namei.c:3912 __do_sys_unlinkat fs/namei.c:4076 [inline] __se_sys_unlinkat fs/namei.c:4070 [inline] __x64_sys_unlinkat+0xdf/0xf0 fs/namei.c:4070 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9e200f7887 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:00007ffc5655e878 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f9e200f7887 RDX: 0000000000000200 RSI: 00007ffc5655fa20 RDI: 00000000ffffff9c RBP: 00007f9e201546c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffc5655fa20 R13: 00007f9e201546c6 R14: 000000000000c3f4 R15: 0000000000000000 Allocated by task 356: 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+0xdb/0x110 mm/kasan/common.c:509 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x18a/0x2e0 mm/slub.c:2974 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] kcov_open+0x23/0x60 kernel/kcov.c:497 open_proxy_open+0x2d4/0x490 fs/debugfs/file.c:205 do_dentry_open+0x7c1/0x10d0 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x2660/0x3000 fs/namei.c:3509 do_filp_open+0x21c/0x460 fs/namei.c:3536 do_sys_openat2+0x13f/0x710 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+0x243/0x290 fs/open.c:1244 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 357: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x121/0x160 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:1595 [inline] slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc3/0x270 mm/slub.c:4191 kcov_put kernel/kcov.c:409 [inline] kcov_close+0x33/0x50 kernel/kcov.c:510 __fput+0x33d/0x7b0 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x129/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xc83/0x2a50 kernel/exit.c:863 do_group_exit+0x141/0x310 kernel/exit.c:985 get_signal+0x10a0/0x1410 kernel/signal.c:2793 arch_do_signal_or_restart+0xbd/0x17c0 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0x9b/0xd0 kernel/entry/common.c:169 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline] syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88810eb23000 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff88810eb23000, ffff88810eb23040) The buggy address belongs to the page: page:ffffea00043ac8c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10eb23 flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea00043ac580 0000000300000003 ffff888100043800 raw: 0000000000000000 0000000000200020 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 95, ts 4493723494, free_ts 4493679386 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348 allocate_slab mm/slub.c:1808 [inline] new_slab+0x80/0x400 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x302/0x4b0 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] __kmalloc+0x204/0x330 mm/slub.c:4029 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:664 [inline] kobject_get_path+0xbc/0x1f0 lib/kobject.c:184 kobject_uevent_env+0x27f/0x700 lib/kobject_uevent.c:544 kobject_synth_uevent+0x4eb/0xae0 lib/kobject_uevent.c:208 uevent_store+0x4b/0x70 drivers/base/bus.c:587 drv_attr_store+0x78/0xa0 drivers/base/bus.c:77 sysfs_kf_write+0x123/0x140 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x2c4/0x410 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2058 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0xb4c/0xe70 fs/read_write.c:605 ksys_write+0x199/0x2c0 fs/read_write.c:658 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+0x2ae/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page+0x9e/0x370 mm/page_alloc.c:5407 __free_pages+0x67/0xc0 mm/page_alloc.c:5418 free_pages+0x7c/0x90 mm/page_alloc.c:5429 selinux_genfs_get_sid+0x24d/0x2a0 security/selinux/hooks.c:1326 inode_doinit_with_dentry+0x86f/0x1050 security/selinux/hooks.c:1523 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6389 security_d_instantiate+0x9f/0x100 security/security.c:1980 d_splice_alias+0x6d/0x390 fs/dcache.c:3036 kernfs_iop_lookup+0x2a4/0x2f0 fs/kernfs/dir.c:1178 lookup_open fs/namei.c:3226 [inline] open_last_lookups fs/namei.c:3317 [inline] path_openat+0x11ab/0x3000 fs/namei.c:3506 do_filp_open+0x21c/0x460 fs/namei.c:3536 do_sys_openat2+0x13f/0x710 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+0x243/0x290 fs/open.c:1244 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff88810eb22f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88810eb22f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88810eb23000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88810eb23080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88810eb23100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================