================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2913 Read of size 4 at addr ffff88812c153000 by task syz-executor/457 CPU: 1 PID: 457 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:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x1e0 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:418 kasan_report+0x122/0x150 mm/kasan/report.c:522 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2913 ext4_evict_inode+0xe58/0x1460 fs/ext4/inode.c:296 evict+0x493/0x890 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x620/0x670 fs/inode.c:1860 d_delete_notify include/linux/fsnotify.h:292 [inline] vfs_rmdir+0x3bf/0x500 fs/namei.c:4203 do_rmdir+0x259/0x6a0 fs/namei.c:4251 __do_sys_unlinkat fs/namei.c:4431 [inline] __se_sys_unlinkat fs/namei.c:4425 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4425 x64_sys_call+0x79f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f47b6779457 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:00007ffe21b3b788 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f47b6779457 RDX: 0000000000000200 RSI: 00007ffe21b3c930 RDI: 00000000ffffff9c RBP: 00007f47b67e77b4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffe21b3c930 R13: 00007f47b67e77b4 R14: 000000000000b40c R15: 00007ffe21b3eae0 Allocated by task 328: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:379 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:388 kasan_kmalloc include/linux/kasan.h:212 [inline] kmalloc_node_trace+0x3d/0xb0 mm/slab_common.c:1045 kmalloc_node include/linux/slab.h:585 [inline] kzalloc_node include/linux/slab.h:710 [inline] __get_vm_area_node+0x12c/0x360 mm/vmalloc.c:2515 __vmalloc_node_range+0x326/0x13d0 mm/vmalloc.c:3216 __vmalloc_node mm/vmalloc.c:3321 [inline] __vmalloc_area_node mm/vmalloc.c:3067 [inline] __vmalloc_node_range+0x52d/0x13d0 mm/vmalloc.c:3256 vmalloc_user+0x73/0x80 mm/vmalloc.c:3410 kcov_ioctl+0x57/0x640 kernel/kcov.c:713 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 329: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1771 slab_free mm/slub.c:3686 [inline] __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3702 kfree+0x6f/0xf0 mm/slab_common.c:990 __vunmap+0xab0/0xb70 mm/vmalloc.c:2748 __vfree mm/vmalloc.c:2788 [inline] vfree+0x61/0x90 mm/vmalloc.c:2819 kvfree+0x26/0x40 mm/util.c:637 __vunmap+0xaa6/0xb70 mm/vmalloc.c:2745 __vfree mm/vmalloc.c:2788 [inline] vfree+0x61/0x90 mm/vmalloc.c:2819 kcov_put kernel/kcov.c:437 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:533 __fput+0x1fc/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1db/0x240 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa25/0x2650 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 get_signal+0x13b5/0x1520 kernel/signal.c:2889 arch_do_signal_or_restart+0xb0/0x1030 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88812c153000 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff88812c153000, ffff88812c153040) The buggy address belongs to the physical page: page:ffffea0004b054c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12c153 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100042780 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 328, tgid 328 (syz-executor), ts 24408043248, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3462 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] kcov_open+0x23/0x60 kernel/kcov.c:520 open_proxy_open+0x3a2/0x4f0 fs/debugfs/file.c:205 do_dentry_open+0x88e/0x1260 fs/open.c:884 vfs_open+0x73/0x80 fs/open.c:1015 do_open fs/namei.c:3625 [inline] path_openat+0x2681/0x2f50 fs/namei.c:3782 do_filp_open+0x1c1/0x3c0 fs/namei.c:3809 page_owner free stack trace missing Memory state around the buggy address: ffff88812c152f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88812c152f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88812c153000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff88812c153080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88812c153100: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem.