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KASAN: use-after-free Read in ntfs_iget5 (3)

Status: upstream: reported on 2026/01/12 20:01
Reported-by: syzbot+068c6664d354756b7b39@syzkaller.appspotmail.com
First crash: 16d, last: 10d
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 19 7 804d 1051d 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 871d 1012d 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 161d 422d 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 568d 667d 0/3 auto-obsoleted due to no activity on 2024/10/18 06:28
upstream KASAN: slab-out-of-bounds Read in ntfs_iget5 ntfs3 19 C done done 3633 743d 1378d 25/29 fixed on 2024/03/20 11:33
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 (2) origin:upstream 19 C error 47 5d17h 671d 0/3 upstream: reported C repro on 2024/03/29 09:18
linux-6.6 KASAN: slab-use-after-free Read in ntfs_iget5 19 8 3d18h 163d 0/2 upstream: reported on 2025/08/19 13:23
upstream BUG: unable to handle kernel paging request in ntfs_iget5 ntfs3 8 1 626d 622d 0/29 auto-obsoleted due to no activity on 2024/08/10 16:42

Sample crash report:
ntfs3: loop0: Different NTFS' sector size (2048) and media sector size (512)
==================================================================
BUG: KASAN: use-after-free in ntfs_iget5+0x14a/0x36c0 fs/ntfs3/inode.c:527
Read of size 8 at addr ffff8880745c9340 by task syz.0.2244/9474

CPU: 0 PID: 9474 Comm: syz.0.2244 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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_iget5+0x14a/0x36c0 fs/ntfs3/inode.c:527
 ntfs_fill_super+0x1db1/0x37b0 fs/ntfs3/super.c:1004
 get_tree_bdev+0x3f1/0x610 fs/super.c:1325
 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: 0033:0x7ff93aa57f4a
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:00007ff938cb1e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff938cb1ee0 RCX: 00007ff93aa57f4a
RDX: 000020000001f380 RSI: 000020000001f3c0 RDI: 00007ff938cb1ea0
RBP: 000020000001f380 R08: 00007ff938cb1ee0 R09: 0000000000200003
R10: 0000000000200003 R11: 0000000000000246 R12: 000020000001f3c0
R13: 00007ff938cb1ea0 R14: 000000000001f384 R15: 0000200000000000
 </TASK>

Allocated by task 9089:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 reiserfs_alloc_inode+0x19/0xb0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0x9e/0x250 fs/inode.c:1263
 reiserfs_fill_super+0x122d/0x2440 fs/reiserfs/super.c:2057
 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

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x189/0x950 kernel/rcu/tree.c:3091
 destroy_inode fs/inode.c:316 [inline]
 evict+0x834/0x8d0 fs/inode.c:662
 reiserfs_fill_super+0x14c4/0x2440 fs/reiserfs/super.c:2082
 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

Second to last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x189/0x950 kernel/rcu/tree.c:3091
 destroy_inode fs/inode.c:316 [inline]
 evict+0x834/0x8d0 fs/inode.c:662
 dispose_list fs/inode.c:680 [inline]
 evict_inodes+0x60c/0x6a0 fs/inode.c:734
 generic_shutdown_super+0x93/0x300 fs/super.c:454
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff8880745c8d40
 which belongs to the cache reiser_inode_cache of size 1568
The buggy address is located 1536 bytes inside of
 1568-byte region [ffff8880745c8d40, ffff8880745c9360)
The buggy address belongs to the page:
page:ffffea0001d17200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880745ca120 pfn:0x745c8
head:ffffea0001d17200 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888026207e01
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146492000
raw: ffff8880745ca120 0000000080130010 00000001ffffffff ffff888026207e01
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 4442, ts 79699274861, free_ts 77983682959
 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:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 reiserfs_alloc_inode+0x19/0xb0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0x9e/0x250 fs/inode.c:1263
 reiserfs_fill_super+0x122d/0x2440 fs/reiserfs/super.c:2057
 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
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+0x8f/0x2a0 mm/page_alloc.c:3396
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 vm_area_dup+0x1e/0xb0 kernel/fork.c:358
 __split_vma+0xb1/0x410 mm/mmap.c:2730
 __do_munmap+0x383/0xdf0 mm/mmap.c:2856
 __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:
 ffff8880745c9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880745c9280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880745c9300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                           ^
 ffff8880745c9380: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00
 ffff8880745c9400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/19 09:10 linux-5.15.y 68efe5a6c16a a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/01/12 20:00 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
* Struck through repros no longer work on HEAD.