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

Status: upstream: reported on 2026/01/20 09:45
Reported-by: syzbot+88b54d8003ee0ada5989@syzkaller.appspotmail.com
First crash: 9d05h, last: 5d16h
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in ntfs_test_inode fs 19 5 750d 750d 0/29 auto-obsoleted due to no activity on 2024/04/18 20:01
upstream KASAN: use-after-free Read in ntfs_test_inode ntfs3 19 C done 402 783d 1718d 25/29 fixed on 2023/12/21 01:43
linux-5.15 KASAN: use-after-free Read in ntfs_test_inode (2) 19 20 85d 521d 0/3 upstream: reported on 2024/08/26 01:18
linux-6.1 KASAN: use-after-free Read in ntfs_test_inode (2) 19 8 70d 385d 0/3 upstream: reported on 2025/01/09 09:49
linux-4.19 KASAN: use-after-free Read in ntfs_test_inode 19 1 1157d 1157d 0/1 auto-obsoleted due to no activity on 2023/03/28 18:25
linux-6.1 KASAN: use-after-free Read in ntfs_test_inode 19 2 675d 677d 0/3 auto-obsoleted due to no activity on 2024/07/03 10:22
linux-5.15 KASAN: use-after-free Read in ntfs_test_inode 19 6 841d 1041d 0/3 auto-obsoleted due to no activity on 2024/01/19 06:00
linux-4.14 KASAN: slab-out-of-bounds Read in ntfs_test_inode 17 1 1442d 1442d 0/1 auto-closed as invalid on 2022/06/16 22:11

Sample crash report:
ntfs: (device loop1): ntfs_read_locked_inode(): Failed with error code -5.  Marking corrupt inode 0xa as bad.  Run chkdsk.
ntfs: (device loop1): load_and_init_upcase(): Failed to load $UpCase from the volume. Using default.
ntfs: volume version 3.1.
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in NInoAttr fs/ntfs/inode.h:200 [inline]
BUG: KASAN: slab-use-after-free in ntfs_test_inode+0x7d/0x2d0 fs/ntfs/inode.c:55
Read of size 8 at addr ffff88807f2d8560 by task syz.1.2354/11076

CPU: 0 PID: 11076 Comm: syz.1.2354 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x241/0x290 mm/kasan/generic.c:187
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 NInoAttr fs/ntfs/inode.h:200 [inline]
 ntfs_test_inode+0x7d/0x2d0 fs/ntfs/inode.c:55
 find_inode+0x19e/0x400 fs/inode.c:946
 ilookup5_nowait fs/inode.c:1501 [inline]
 ilookup5+0xab/0x1e0 fs/inode.c:1530
 iget5_locked+0x34/0x260 fs/inode.c:1311
 ntfs_iget+0xbd/0x1a0 fs/ntfs/inode.c:168
 load_and_check_logfile+0x3f/0xd0 fs/ntfs/super.c:1216
 load_system_files+0x2f1b/0x4550 fs/ntfs/super.c:1949
 ntfs_fill_super+0x1818/0x2a50 fs/ntfs/super.c:2900
 mount_bdev+0x221/0x2d0 fs/super.c:1643
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fad0719bf4a
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:00007fad0801be58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fad0801bee0 RCX: 00007fad0719bf4a
RDX: 0000200000000100 RSI: 0000200000000000 RDI: 00007fad0801bea0
RBP: 0000200000000100 R08: 00007fad0801bee0 R09: 0000000001800010
R10: 0000000001800010 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fad0801bea0 R14: 000000000001ee86 R15: 000020000001f340
 </TASK>

Allocated by task 6403:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc_lru+0x111/0x2d0 mm/slub.c:3526
 alloc_inode_sb include/linux/fs.h:2946 [inline]
 reiserfs_alloc_inode+0x2a/0xc0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0xa2/0x260 fs/inode.c:1314
 reiserfs_fill_super+0x11d7/0x23b0 fs/reiserfs/super.c:2053
 mount_bdev+0x221/0x2d0 fs/super.c:1643
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2721 [inline]
 call_rcu+0x153/0x950 kernel/rcu/tree.c:2837
 destroy_inode fs/inode.c:316 [inline]
 evict+0x835/0x8d0 fs/inode.c:720
 reiserfs_fill_super+0x1479/0x23b0 fs/reiserfs/super.c:2078
 mount_bdev+0x221/0x2d0 fs/super.c:1643
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88807f2d8000
 which belongs to the cache reiser_inode_cache of size 1568
The buggy address is located 1376 bytes inside of
 freed 1568-byte region [ffff88807f2d8000, ffff88807f2d8620)

The buggy address belongs to the physical page:
page:ffffea0001fcb600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807f2d8000 pfn:0x7f2d8
head:ffffea0001fcb600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888030492701
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888140086c80 dead000000000122 0000000000000000
raw: ffff88807f2d8000 0000000080130012 00000001ffffffff ffff888030492701
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 6403, tgid 6402 (syz.3.373), ts 108466750446, free_ts 103661469413
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3191
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x160 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc_lru+0x1aa/0x2d0 mm/slub.c:3526
 alloc_inode_sb include/linux/fs.h:2946 [inline]
 reiserfs_alloc_inode+0x2a/0xc0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0xa2/0x260 fs/inode.c:1314
 reiserfs_fill_super+0x11d7/0x23b0 fs/reiserfs/super.c:2053
 mount_bdev+0x221/0x2d0 fs/super.c:1643
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 __slab_free+0x35a/0x400 mm/slub.c:3736
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519
 getname_flags+0xbb/0x500 fs/namei.c:140
 do_sys_openat2+0xda/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88807f2d8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807f2d8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807f2d8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88807f2d8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807f2d8600: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/20 09:44 linux-6.6.y cbb31f77b879 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_test_inode
2026/01/23 21:59 linux-6.6.y cbb31f77b879 4f25b9b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-out-of-bounds Read in ntfs_test_inode
* Struck through repros no longer work on HEAD.