KASAN: slab-use-after-free Read in ntfs_iget5

Status: upstream: reported on 2025/08/19 13:23
Reported-by: syzbot+6d08037c33272de1e5a0@syzkaller.appspotmail.com
First crash: 341d, last: 16d
▶ ▼ 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_iget5 actionable prio:high ntfs3 19 9 53d 118d 0/29 upstream: reported on 2026/03/31 11:55
upstream KASAN: slab-out-of-bounds Read in ntfs_iget5 ntfs3 19 C done done 3633 922d 1556d 25/29 fixed on 2024/03/20 11:33
upstream BUG: unable to handle kernel paging request in ntfs_iget5 ntfs3 8 1 805d 801d 0/29 auto-obsoleted due to no activity on 2024/08/10 16:42
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 19 7 983d 1229d 0/3 auto-obsoleted due to no activity on 2024/02/25 08:58
linux-5.15 KASAN: use-after-free Read in ntfs_iget5 19 5 1050d 1191d 0/3 auto-obsoleted due to no activity on 2023/12/20 11:31
linux-5.15 KASAN: slab-out-of-bounds Read in ntfs_iget5 19 31 339d 601d 0/3 auto-obsoleted due to no activity on 2025/11/29 13:33
linux-5.15 KASAN: use-after-free Read in ntfs_iget5 (2) 19 5 747d 846d 0/3 auto-obsoleted due to no activity on 2024/10/18 06:28
linux-5.15 KASAN: use-after-free Read in ntfs_iget5 (3) origin:lts-only 19 syz done 17 17d 195d 0/3 upstream: reported syz repro on 2026/01/12 20:01
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 (2) origin:upstream 19 C error 56 72d 850d 0/3 upstream: reported C repro on 2024/03/29 09:18

Sample crash report:
loop3: detected capacity change from 0 to 4096
ntfs3: loop3: Different NTFS sector size (1024) and media sector size (512).
ntfs3: loop3: Mark volume as dirty due to NTFS errors
==================================================================
BUG: KASAN: slab-use-after-free in ntfs_read_mft fs/ntfs3/inode.c:79 [inline]
BUG: KASAN: slab-use-after-free in ntfs_iget5+0x34f1/0x37f0 fs/ntfs3/inode.c:535
Read of size 2 at addr ffff88805d89e23e by task syz.3.421/6842

CPU: 0 PID: 6842 Comm: syz.3.421 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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
 ntfs_read_mft fs/ntfs3/inode.c:79 [inline]
 ntfs_iget5+0x34f1/0x37f0 fs/ntfs3/inode.c:535
 ntfs_dir_emit fs/ntfs3/dir.c:338 [inline]
 ntfs_read_hdr+0x77c/0xbd0 fs/ntfs3/dir.c:386
 ntfs_readdir+0x687/0xe00 fs/ntfs3/dir.c:458
 iterate_dir+0x1bd/0x590 fs/readdir.c:106
 __do_sys_getdents fs/readdir.c:322 [inline]
 __se_sys_getdents+0xf6/0x260 fs/readdir.c:307
 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: 0033:0x7fe70219de59
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:00007fe7030a0028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007fe702425fa0 RCX: 00007fe70219de59
RDX: 0000000000000057 RSI: 0000200000000f00 RDI: 0000000000000004
RBP: 00007fe702233e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe702426038 R14: 00007fe702425fa0 R15: 00007ffedec804d8
 </TASK>

Allocated by task 6842:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc+0xb7/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 mi_init+0x76/0xe0 fs/ntfs3/record.c:105
 ntfs_read_mft fs/ntfs3/inode.c:54 [inline]
 ntfs_iget5+0x36b/0x37f0 fs/ntfs3/inode.c:535
 dir_search_u+0x1fe/0x2e0 fs/ntfs3/dir.c:264
 ntfs_lookup+0x100/0x1d0 fs/ntfs3/namei.c:85
 __lookup_slow+0x2a1/0x400 fs/namei.c:1702
 lookup_slow+0x53/0x70 fs/namei.c:1719
 walk_component+0x2ad/0x3e0 fs/namei.c:2010
 lookup_last fs/namei.c:2467 [inline]
 path_lookupat+0x148/0x420 fs/namei.c:2491
 filename_lookup+0x22d/0x580 fs/namei.c:2520
 user_path_at_empty+0x42/0x60 fs/namei.c:2917
 user_path_at include/linux/namei.h:57 [inline]
 do_fchownat+0xf9/0x240 fs/open.c:808
 __do_sys_chown fs/open.c:834 [inline]
 __se_sys_chown fs/open.c:832 [inline]
 __x64_sys_chown+0x82/0x90 fs/open.c:832
 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

Freed by task 49:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 ni_try_remove_attr_list+0xd45/0xef0 fs/ntfs3/frecord.c:-1
 ni_write_inode+0xa90/0xfd0 fs/ntfs3/frecord.c:3351
 write_inode fs/fs-writeback.c:1483 [inline]
 __writeback_single_inode+0x720/0xee0 fs/fs-writeback.c:1700
 writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1926
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:1997
 wb_writeback+0x472/0xbe0 fs/fs-writeback.c:2107
 wb_check_background_flush fs/fs-writeback.c:2177 [inline]
 wb_do_writeback fs/fs-writeback.c:2265 [inline]
 wb_workfn+0xb8e/0xe60 fs/fs-writeback.c:2292
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

The buggy address belongs to the object at ffff88805d89e000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 574 bytes inside of
 freed 1024-byte region [ffff88805d89e000, ffff88805d89e400)

The buggy address belongs to the physical page:
page:ffffea0001762600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d898
head:ffffea0001762600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017c41dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 59, tgid 59 (kworker/u4:4), ts 75096148614, free_ts 75091432203
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
 prep_new_page mm/page_alloc.c:1589 [inline]
 get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
 alloc_slab_page+0x5d/0x180 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5c/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]
 __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0xa4/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 pskb_expand_head+0x17a/0x1150 net/core/skbuff.c:2101
 __skb_cow include/linux/skbuff.h:3681 [inline]
 skb_cow_head include/linux/skbuff.h:3715 [inline]
 batadv_skb_head_push+0x166/0x200 net/batman-adv/soft-interface.c:72
 batadv_send_skb_packet+0xed/0x660 net/batman-adv/send.c:86
 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:395 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:423 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x65b/0x800 net/batman-adv/bat_iv_ogm.c:1792
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1182 [inline]
 free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459
 discard_slab mm/slub.c:2127 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667
 put_cpu_partial+0x17c/0x250 mm/slub.c:2743
 __slab_free+0x319/0x400 mm/slub.c:3700
 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+0x6a/0x4d0 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+0x17e/0x2c0 mm/slub.c:3519
 getname_flags+0xbb/0x500 fs/namei.c:140
 user_path_at_empty+0x2c/0x60 fs/namei.c:2916
 do_readlinkat+0xdd/0x490 fs/stat.c:494
 __do_sys_readlink fs/stat.c:527 [inline]
 __se_sys_readlink fs/stat.c:524 [inline]
 __x64_sys_readlink+0x7f/0x90 fs/stat.c:524
 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

Memory state around the buggy address:
 ffff88805d89e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805d89e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805d89e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88805d89e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805d89e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/11 04:53 linux-6.6.y da47cbc25466 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/06/01 20:36 linux-6.6.y 924b4a879cbb 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/05/04 20:00 linux-6.6.y 258cf62a6dfd a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/04/29 20:46 linux-6.6.y 142cd8382222 005438fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/04/28 20:35 linux-6.6.y 142cd8382222 95008c03 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/04/21 03:56 linux-6.6.y 9760bf04666d 3f2e655b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/04/17 14:49 linux-6.6.y 8cee53b8eaeb 24ecfc1e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/03/28 02:27 linux-6.6.y c09fbcd31ae6 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/03/20 15:16 linux-6.6.y 4fc00fe35d46 ac6f1dff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/03/06 00:10 linux-6.6.y 4fc00fe35d46 31e9c887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/02/19 18:32 linux-6.6.y 7a137e9bfa0e c8d8c52d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/01/30 10:48 linux-6.6.y 2cf6f68313dc bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/01/23 09:44 linux-6.6.y cbb31f77b879 e2b1b6e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/01/19 22:15 linux-6.6.y cbb31f77b879 572effc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2025/11/25 01:18 linux-6.6.y 1e89a1be4fe9 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2025/10/06 10:51 linux-6.6.y e617101e5626 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2025/10/01 23:43 linux-6.6.y 147338df3487 267f56c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2025/08/20 02:21 linux-6.6.y bb9c90ab9c5a 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2025/08/19 13:22 linux-6.6.y bb9c90ab9c5a 254a27c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in ntfs_iget5
2026/03/24 13:01 linux-6.6.y 4fc00fe35d46 74e70d19 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-out-of-bounds Read in ntfs_iget5
2026/03/17 20:06 linux-6.6.y 4fc00fe35d46 c8810548 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-out-of-bounds Read in ntfs_iget5
2026/01/25 21:09 linux-6.6.y cbb31f77b879 55756628 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in ntfs_iget5
* Struck through repros no longer work on HEAD.