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

Status: upstream: reported syz repro on 2026/01/12 20:01
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+068c6664d354756b7b39@syzkaller.appspotmail.com
First crash: 236d, last: 11d
Fix commit to backport (bisect log) :
tree: upstream
commit fb6f20ecb121cef4d7946f834a6ee867c4e21b4a
Author: Jan Kara <jack@suse.cz>
Date: Thu Oct 17 10:28:23 2024 +0000

  reiserfs: The last commit

  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/04/12 linux-5.15.y (ToT) 91d48252ad4b syz [report] general protection fault in ntfs_iget5
2026/04/12 upstream (ToT) f5459048c38a syz Didn't crash
▶ ▼ Similar bugs (9)
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 1023d 1270d 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 1090d 1231d 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 380d 642d 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 788d 887d 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 syz, C done done 3633 963d 1597d 25/29 fixed on 2024/03/20 11:33
linux-6.1 KASAN: use-after-free Read in ntfs_iget5 (2) origin:upstream 19 syz, C error 56 113d 890d 0/3 upstream: reported C repro on 2024/03/29 09:18
upstream KASAN: slab-use-after-free Read in ntfs_iget5 actionable prio:high ntfs3 19 9 94d 158d 0/29 upstream: reported on 2026/03/31 11:55
linux-6.6 KASAN: slab-use-after-free Read in ntfs_iget5 19 22 57d 382d 0/2 upstream: reported on 2025/08/19 13:23
upstream BUG: unable to handle kernel paging request in ntfs_iget5 ntfs3 8 1 846d 842d 0/29 auto-obsoleted due to no activity on 2024/08/10 16:42
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/07/01 07:28 23m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2026/07/23 03:31 8h19m fix candidate upstream OK (1) job log
2026/04/12 14:10 1m fix candidate upstream error job log

Sample crash report:
ntfs3: loop0: Different NTFS' sector size (4096) and media sector size (512)
==================================================================
BUG: KASAN: use-after-free in ntfs_iget5+0x14a/0x3760 fs/ntfs3/inode.c:528
Read of size 8 at addr ffff888058cfff60 by task syz.0.515/5436

CPU: 1 PID: 5436 Comm: syz.0.515 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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_iget5+0x14a/0x3760 fs/ntfs3/inode.c:528
 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: 0033:0x7f9dc1b0ca8a
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:00007f9dc116ce58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9dc116cee0 RCX: 00007f9dc1b0ca8a
RDX: 000020000001f180 RSI: 000020000001f1c0 RDI: 00007f9dc116cea0
RBP: 000020000001f180 R08: 00007f9dc116cee0 R09: 000000000000000e
R10: 000000000000000e R11: 0000000000000246 R12: 000020000001f1c0
R13: 00007f9dc116cea0 R14: 000000000001f174 R15: 00002000000000c0
 </TASK>

The buggy address belongs to the page:
page:ffffea0001633fc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58cff
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 ffffea0001633f88 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
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 4342, ts 329903020480, free_ts 340123697775
 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_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
 sock_alloc_inode+0x17/0xb0 net/socket.c:305
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x5f/0x210 fs/inode.c:1001
 sock_alloc net/socket.c:628 [inline]
 __sock_create+0x129/0x900 net/socket.c:1459
 sock_create net/socket.c:1551 [inline]
 __sys_socket+0xe2/0x170 net/socket.c:1593
 __do_sys_socket net/socket.c:1602 [inline]
 __se_sys_socket net/socket.c:1600 [inline]
 __x64_sys_socket+0x76/0x80 net/socket.c:1600
 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
 free_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 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
 inotify_new_watch fs/notify/inotify/inotify_user.c:592 [inline]
 inotify_update_watch fs/notify/inotify/inotify_user.c:640 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:779 [inline]
 __se_sys_inotify_add_watch+0x6c7/0xeb0 fs/notify/inotify/inotify_user.c:722
 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:
 ffff888058cffe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888058cffe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888058cfff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                       ^
 ffff888058cfff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888058d00000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/11 16:58 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2 (corrupt fs)] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/08/25 11:57 linux-5.15.y 945fa863f02c a9a1fc32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/08/24 11:01 linux-5.15.y 945fa863f02c b55bd4c3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/07/10 00:25 linux-5.15.y c86c4726e7f0 4167ee25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/06/16 23:02 linux-5.15.y dc027a595035 62cc6db3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/06/05 23:29 linux-5.15.y dc027a595035 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/05/20 23:38 linux-5.15.y 93741761e5e3 41b8c833 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/05/18 09:12 linux-5.15.y 93741761e5e3 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/05/12 19:55 linux-5.15.y de8dfb3f0278 a0949470 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/05/08 13:06 linux-5.15.y 7e75ef31ddc9 b2988c17 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/04/28 20:27 linux-5.15.y b9d57c40a767 95008c03 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/04/16 23:49 linux-5.15.y 91d48252ad4b de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/04/15 11:10 linux-5.15.y 91d48252ad4b c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/03/11 17:06 linux-5.15.y 91d48252ad4b 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/03/04 11:33 linux-5.15.y 3330a8d33e08 e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in ntfs_iget5
2026/01/19 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
2026/08/18 05:33 linux-5.15.y aabd761612db 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in ntfs_iget5
2026/08/18 05:31 linux-5.15.y aabd761612db 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in ntfs_iget5
2026/05/23 13:15 linux-5.15.y 241d66fa280c c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in ntfs_iget5
2026/05/20 10:46 linux-5.15.y 93741761e5e3 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in ntfs_iget5
* Struck through repros no longer work on HEAD.