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: 210d, last: 83d
▶ ▼ Similar bugs (9)
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 951d 951d 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 syz, C done 402 985d 1919d 25/29 fixed on 2023/12/21 01:43
linux-5.15 KASAN: use-after-free Read in ntfs_test_inode (3) 19 10 67d 147d 0/3 upstream: reported on 2026/03/24 00:25
linux-5.15 KASAN: use-after-free Read in ntfs_test_inode (2) 19 20 286d 722d 0/3 auto-obsoleted due to no activity on 2026/02/13 06:39
linux-6.1 KASAN: use-after-free Read in ntfs_test_inode (2) 19 16 105d 586d 0/3 auto-obsoleted due to no activity on 2026/08/13 09:22
linux-4.19 KASAN: use-after-free Read in ntfs_test_inode 19 1 1359d 1359d 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 876d 878d 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 1042d 1242d 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 1643d 1643d 0/1 auto-closed as invalid on 2022/06/16 22:11

Sample crash report:
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 ffff88805b4f0560 by task syz.3.6984/21557

CPU: 0 PID: 21557 Comm: syz.3.6984 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f861639e0ca
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:00007f861720ae58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f861720aee0 RCX: 00007f861639e0ca
RDX: 000020000001f600 RSI: 000020000001f640 RDI: 00007f861720aea0
RBP: 000020000001f600 R08: 00007f861720aee0 R09: 0000000000808884
R10: 0000000000808884 R11: 0000000000000246 R12: 000020000001f640
R13: 00007f861720aea0 R14: 000000000001f5d0 R15: 000020000001f680
 </TASK>

Allocated by task 8071:
 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+0x55/0xb0 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+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88805b4f0000
 which belongs to the cache reiser_inode_cache of size 1568
The buggy address is located 1376 bytes inside of
 freed 1568-byte region [ffff88805b4f0000, ffff88805b4f0620)

The buggy address belongs to the physical page:
page:ffffea00016d3c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805b4f2e60 pfn:0x5b4f0
head:ffffea00016d3c00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802dfd9c01
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888142ea2dc0 dead000000000122 0000000000000000
raw: ffff88805b4f2e60 000000008013000d 00000001ffffffff ffff88802dfd9c01
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 8071, tgid 8069 (syz.1.952), ts 201105499582, free_ts 21924182059
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
 prep_new_page mm/page_alloc.c:1588 [inline]
 get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500
 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+0x55/0xb0 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:1181 [inline]
 free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458
 free_contig_range+0xa1/0x150 mm/page_alloc.c:6420
 destroy_args+0x80/0x850 mm/debug_vm_pgtable.c:1015
 debug_vm_pgtable+0x411/0x440 mm/debug_vm_pgtable.c:1400
 do_one_initcall+0x242/0x790 init/main.c:1249
 do_initcall_level+0x137/0x1f0 init/main.c:1311
 do_initcalls+0x69/0xd0 init/main.c:1327
 kernel_init_freeable+0x3ed/0x580 init/main.c:1564
 kernel_init+0x1d/0x1c0 init/main.c:1454
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Memory state around the buggy address:
 ffff88805b4f0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805b4f0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805b4f0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88805b4f0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805b4f0600: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/27 11:24 linux-6.6.y 0a40c6fbd105 8777bdc3 .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
2026/05/06 11:28 linux-6.6.y 258cf62a6dfd 1dddfd3d .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
2026/05/02 07:28 linux-6.6.y 258cf62a6dfd a0d91488 .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
2026/03/11 17:11 linux-6.6.y 4fc00fe35d46 2d88ab01 .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
2026/01/20 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
2026/02/10 11:11 linux-6.6.y c56aaf1a85ae 91d776d3 .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
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.