KASAN: slab-use-after-free Read in mi_enum_attr

Status: moderation: reported on 2026/04/09 02:36
Subsystems: ntfs3
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+0f60f47896d976d3d3ea@syzkaller.appspotmail.com
First crash: 123d, last: 41d
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
f9d60f57 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: slab-use-after-free Read in mi_enum_attr 2026/05/17 00:02 2026/05/17 00:02 2026/05/17 00:44 de5aae85
40444e8e moderation Actionable: ✅ Confident: ✅ ❓ KASAN: slab-use-after-free Read in mi_enum_attr 2026/04/10 00:01 2026/04/10 00:01 2026/04/10 00:28 38c8e246
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in mi_enum_attr ntfs3 17 syz, C unreliable error 1 705d 916d 0/29 auto-obsoleted due to no activity on 2024/12/08 21:57
upstream BUG: unable to handle kernel paging request in mi_enum_attr ntfs3 19 syz, C error done 18 1309d 1435d 22/29 fixed on 2023/02/24 13:50

Sample crash report:
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in mi_enum_attr+0x806/0x9f0 fs/ntfs3/record.c:233
Read of size 4 at addr ffff8880634e1834 by task syz.2.208/7515

CPU: 1 UID: 0 PID: 7515 Comm: syz.2.208 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 mi_enum_attr+0x806/0x9f0 fs/ntfs3/record.c:233
 mi_find_attr+0x3e/0x2c0 fs/ntfs3/record.c:367
 ni_find_attr+0x1dd/0x570 fs/ntfs3/frecord.c:208
 ni_write_parents+0x332/0x440 fs/ntfs3/frecord.c:2927
 ntfs_file_fsync+0x161/0x260 fs/ntfs3/file.c:1504
 vfs_fsync_range fs/sync.c:186 [inline]
 vfs_fsync fs/sync.c:200 [inline]
 do_fsync fs/sync.c:211 [inline]
 __do_sys_fsync fs/sync.c:216 [inline]
 __se_sys_fsync fs/sync.c:214 [inline]
 __x64_sys_fsync+0x130/0x190 fs/sync.c:214
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f562bc8c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f5629ea4028 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
RAX: ffffffffffffffda RBX: 00007f562bf06180 RCX: 00007f562bc8c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f562bd22c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f562bf06218 R14: 00007f562bf06180 R15: 00007ffd5b501dc8
 </TASK>

Allocated by task 7503:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5260 [inline]
 __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5272
 kmalloc_noprof include/linux/slab.h:954 [inline]
 mi_init fs/ntfs3/record.c:105 [inline]
 mi_format_new+0xeb/0x610 fs/ntfs3/record.c:422
 ni_add_subrecord+0xd1/0x460 fs/ntfs3/frecord.c:323
 ntfs_look_free_mft+0x4e1/0xd70 fs/ntfs3/fsntfs.c:738
 ni_create_attr_list+0x94b/0x1450 fs/ntfs3/frecord.c:830
 ni_ins_attr_ext+0x461/0xba0 fs/ntfs3/frecord.c:928
 ni_insert_attr fs/ntfs3/frecord.c:1095 [inline]
 ni_insert_resident fs/ntfs3/frecord.c:1479 [inline]
 ni_add_name+0x6df/0xc90 fs/ntfs3/frecord.c:2756
 ni_rename+0x4a/0x100 fs/ntfs3/frecord.c:2795
 ntfs_rename+0x6ea/0xb40 fs/ntfs3/namei.c:331
 vfs_rename+0xa96/0xeb0 fs/namei.c:6032
 filename_renameat2+0x539/0x9c0 fs/namei.c:6150
 __do_sys_rename fs/namei.c:6194 [inline]
 __se_sys_rename+0x55/0x2c0 fs/namei.c:6190
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 7504:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1c1/0x6c0 mm/slub.c:6483
 mi_clear fs/ntfs3/ntfs_fs.h:1211 [inline]
 mi_put+0x118/0x190 fs/ntfs3/record.c:97
 ni_write_inode+0xc29/0xff0 fs/ntfs3/frecord.c:3218
 write_inode fs/fs-writeback.c:1582 [inline]
 __writeback_single_inode+0x75d/0x11a0 fs/fs-writeback.c:1825
 writeback_single_inode+0x488/0xd60 fs/fs-writeback.c:1881
 write_inode_now+0x1c2/0x290 fs/fs-writeback.c:2972
 ntfs_file_fsync+0x136/0x260 fs/ntfs3/file.c:1501
 vfs_fsync_range fs/sync.c:186 [inline]
 vfs_fsync fs/sync.c:200 [inline]
 do_fsync fs/sync.c:211 [inline]
 __do_sys_fsync fs/sync.c:216 [inline]
 __se_sys_fsync fs/sync.c:214 [inline]
 __x64_sys_fsync+0x130/0x190 fs/sync.c:214
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880634e1800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 52 bytes inside of
 freed 1024-byte region [ffff8880634e1800, ffff8880634e1c00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x634e0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813fe19dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813fe19dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 0080000000000003 ffffea00018d3801 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2840(GFP_NOWAIT|__GFP_IO|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6650, tgid 6647 (syz.3.107), ts 137406389856, free_ts 136891616209
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3481
 new_slab mm/slub.c:3539 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x35c/0x710 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5272
 kmalloc_noprof include/linux/slab.h:954 [inline]
 xlog_kvmalloc fs/xfs/xfs_log_priv.h:709 [inline]
 xlog_cil_alloc_shadow_bufs fs/xfs/xfs_log_cil.c:335 [inline]
 xlog_cil_commit+0x2e1/0x2ce0 fs/xfs/xfs_log_cil.c:1833
 __xfs_trans_commit+0x3d3/0xc20 fs/xfs/xfs_trans.c:868
 xfs_trans_commit+0x13e/0x1c0 fs/xfs/xfs_trans.c:926
 xfs_qm_qino_alloc+0x5bd/0x730 fs/xfs/xfs_qm.c:997
 xfs_qm_init_quotainos+0x7f4/0xa00 fs/xfs/xfs_qm.c:1787
 xfs_qm_init_quotainfo+0x17c/0x1270 fs/xfs/xfs_qm.c:788
 xfs_qm_mount_quotas+0xa6/0x670 fs/xfs/xfs_qm.c:1633
 xfs_mountfs+0x1b16/0x22e0 fs/xfs/xfs_mount.c:1190
 xfs_fs_fill_super+0x11b5/0x1600 fs/xfs/xfs_super.c:1938
page last free pid 6658 tgid 6657 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978
 __slab_free+0x24f/0x2a0 mm/slub.c:5573
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4873
 ptlock_alloc+0x20/0x70 mm/memory.c:7469
 ptlock_init include/linux/mm.h:3494 [inline]
 pagetable_pte_ctor include/linux/mm.h:3543 [inline]
 __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline]
 pte_alloc_one+0x7e/0x380 arch/x86/mm/pgtable.c:18
 __pte_alloc+0x25/0x1a0 mm/memory.c:466
 do_anonymous_page mm/memory.c:5234 [inline]
 do_pte_missing+0x1ba7/0x29e0 mm/memory.c:4475
 handle_pte_fault mm/memory.c:6317 [inline]
 __handle_mm_fault mm/memory.c:6455 [inline]
 handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6624
 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

Memory state around the buggy address:
 ffff8880634e1700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880634e1780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880634e1800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880634e1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880634e1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/05 02:26 upstream 7ca6d1cfec80 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in mi_enum_attr
2026/06/25 16:02 upstream ab9de95c9cf9 432fd51a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in mi_enum_attr
* Struck through repros no longer work on HEAD.