KASAN: use-after-free Read in ntfs_attr_find

Status: upstream: reported C repro on 2024/01/20 12:39
Bug presence: origin:lts-only
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+0ac549e1686580665949@syzkaller.appspotmail.com
First crash: 917d, last: 62d
Fix commit to backport (bisect log) :
tree: upstream
commit 7ffa8f3d30236e0ab897c30bdb01224ff1fe1c89
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon Jan 15 07:20:25 2024 +0000

  fs: Remove NTFS classic

  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2024/05/19 linux-5.15.y (ToT) 83655231580b C [report] KASAN: use-after-free Read in ntfs_attr_find
2024/05/19 upstream (ToT) 61307b7be41a C Didn't crash
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in ntfs_attr_find ntfs3 19 C done 74 1264d 1430d 22/29 fixed on 2023/02/24 13:50
linux-6.1 KASAN: use-after-free Read in ntfs_attr_find 19 3 1189d 1200d 0/3 auto-obsoleted due to no activity on 2023/08/21 05:46
linux-4.14 KASAN: slab-out-of-bounds Read in ntfs_attr_find (2) 19 C 31 1245d 1430d 0/1 upstream: reported C repro on 2022/08/25 11:21
upstream KASAN: use-after-free Read in ntfs_attr_find (2) ntfs3 19 C error done 22 888d 1242d 0/29 auto-obsoleted due to no activity on 2024/05/28 05:52
linux-4.19 KASAN: use-after-free Read in ntfs_attr_find (2) 19 C 1 1246d 1246d 0/1 upstream: reported C repro on 2023/02/26 02:15
linux-4.14 KASAN: use-after-free Read in ntfs_attr_find 19 C done 4 2112d 2131d 1/1 fixed on 2020/11/12 10:36
linux-4.19 KASAN: use-after-free Read in ntfs_attr_find 19 C done 13 2097d 2128d 1/1 fixed on 2020/11/27 11:32
linux-6.1 KASAN: use-after-free Read in ntfs_attr_find (2) missing-backport origin:lts-only 19 C done 3 593d 946d 0/3 upstream: reported C repro on 2023/12/22 04:54
linux-5.15 KASAN: slab-out-of-bounds Read in ntfs_attr_find 17 1 1188d 1188d 0/3 auto-obsoleted due to no activity on 2023/08/22 04:27
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/05/24 03:53 21m retest repro linux-5.15.y report log
2026/05/24 03:53 16m retest repro linux-5.15.y report log
2026/05/24 03:53 17m retest repro linux-5.15.y report log
2026/05/24 03:53 15m retest repro linux-5.15.y report log
2026/05/24 03:53 22m retest repro linux-5.15.y report log
2026/03/07 20:35 9m retest repro linux-5.15.y report log
2026/02/19 17:55 13m retest repro linux-5.15.y report log
2026/02/19 17:55 2h12m retest repro linux-5.15.y report log
2026/02/19 17:55 2h05m retest repro linux-5.15.y report log
2025/12/27 18:30 9m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/06/29 02:02 6h51m fix candidate upstream OK (1) job log
2024/04/24 18:26 5m fix candidate upstream error job log
2024/02/26 08:03 0m bisect fix linux-5.15.y error job log

Sample crash report:
loop0: detected capacity change from 0 to 4096
==================================================================
BUG: KASAN: use-after-free in ntfs_attr_find+0x79e/0xc30 fs/ntfs/attrib.c:609
Read of size 2 at addr ffff888058c4d442 by task syz.0.17/4324

CPU: 1 PID: 4324 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 ntfs_attr_find+0x79e/0xc30 fs/ntfs/attrib.c:609
 ntfs_attr_lookup+0x212/0x2290 fs/ntfs/attrib.c:1213
 ntfs_read_locked_inode+0xa97/0x4de0 fs/ntfs/inode.c:666
 ntfs_iget+0x108/0x1a0 fs/ntfs/inode.c:177
 load_and_init_mft_mirror fs/ntfs/super.c:1027 [inline]
 load_system_files+0xd8/0x55a0 fs/ntfs/super.c:1772
 ntfs_fill_super+0x19e0/0x2c90 fs/ntfs/super.c:2894
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1b10c4c04a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffe65ea50d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe65ea5160 RCX: 00007f1b10c4c04a
RDX: 000020000001f6c0 RSI: 0000200000000080 RDI: 00007ffe65ea5120
RBP: 000020000001f6c0 R08: 00007ffe65ea5160 R09: 000000000000c70b
R10: 000000000000c70b R11: 0000000000000246 R12: 0000200000000080
R13: 00007ffe65ea5120 R14: 000000000001f670 R15: 0000200000000040
 </TASK>

The buggy address belongs to the page:
page:ffffea0001631340 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x58c4d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001631388 ffff8880b91409a0 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4324, ts 65126565528, free_ts 65154924968
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 do_anonymous_page mm/memory.c:3838 [inline]
 handle_pte_fault mm/memory.c:4648 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x23be/0x4410 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
 release_pages+0x186c/0x1be0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:241 [inline]
 tlb_flush_mmu mm/mmu_gather.c:248 [inline]
 tlb_finish_mmu+0x1b4/0x370 mm/mmu_gather.c:371
 unmap_region+0x344/0x3b0 mm/mmap.c:2669
 __do_munmap+0x9f8/0xdf0 mm/mmap.c:2899
 __vm_munmap+0x140/0x240 mm/mmap.c:2952
 __do_sys_munmap mm/mmap.c:2978 [inline]
 __se_sys_munmap mm/mmap.c:2974 [inline]
 __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff888058c4d300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888058c4d380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888058c4d400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff888058c4d480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888058c4d500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/03 13:29 linux-5.15.y ef251c45f1cd a0d91488 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_attr_find
2024/05/19 16:21 linux-5.15.y 83655231580b c0f1611a .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_attr_find
2024/09/15 09:39 linux-5.15.y 3a5928702e71 08d8a733 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in ntfs_attr_find
2024/03/16 07:45 linux-5.15.y b95c01af2113 d615901c .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in ntfs_attr_find
2024/01/20 12:50 linux-5.15.y ddcaf4999061 9bd8dcda .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in ntfs_attr_find
2024/01/20 12:39 linux-5.15.y ddcaf4999061 9bd8dcda .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in ntfs_attr_find
* Struck through repros no longer work on HEAD.