KMSAN: uninit-value in ntfs_read_hdr (3)

Status: fixed on 2026/01/07 12:29
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+332bd4e9d148f11a87dc@syzkaller.appspotmail.com
Fix commit: a8a3ca23bbd9 fs/ntfs3: Initialize allocated memory before use 9948dcb2f7b5 ntfs3: Fix uninit buffer allocated by __getname()
First crash: 330d, last: 223d
▶ ▼ Discussions (7)
Title Replies (including bot) Last reply
[PATCH 5.15.y] fs/ntfs3: Initialize allocated memory before use 1 (1) 2026/01/26 06:19
[PATCH 6.1.y] fs/ntfs3: Initialize allocated memory before use 1 (1) 2026/01/26 06:19
[PATCH 6.6.y] fs/ntfs3: Initialize allocated memory before use 1 (1) 2026/01/23 06:57
[PATCH 6.12.y] fs/ntfs3: Initialize allocated memory before use 1 (1) 2026/01/23 03:42
[PATCH linux-next] fs/ntfs3: Initialize allocated memory before use 3 (3) 2025/11/20 09:07
[PATCH v1] ntfs3: Fix uninit buffer allocated by __getname() 2 (2) 2025/11/20 08:47
[syzbot] [ntfs3?] KMSAN: uninit-value in ntfs_read_hdr (3) 0 (6) 2025/11/05 07:52
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in ntfs_read_hdr (4) ntfs3 7 3 195d 205d 0/29 auto-obsoleted due to no activity on 2026/05/10 14:12
upstream KMSAN: uninit-value in ntfs_read_hdr (2) ntfs3 7 1 472d 468d 0/29 auto-obsoleted due to no activity on 2025/08/06 10:39
upstream KMSAN: uninit-value in ntfs_read_hdr ntfs3 7 15 586d 641d 0/29 auto-obsoleted due to no activity on 2025/03/15 12:38
upstream KASAN: slab-use-after-free Read in ntfs_read_hdr actionable prio:high ntfs3 19 2 84d 72d 0/29 upstream: reported on 2026/06/01 20:12
▶ ▼ Last patch testing requests (6)
Created Duration User Patch Repo Result
2025/11/05 07:52 33m kubik.bartlomiej@gmail.com patch https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master OK log
2025/10/29 20:03 45m kubik.bartlomiej@gmail.com patch upstream OK log
2025/10/26 15:54 28m kubik.bartlomiej@gmail.com patch upstream OK log
2025/10/01 13:07 20m retest repro upstream report log
2025/09/22 18:03 1h37m sidharthseela@gmail.com patch upstream OK log
2025/09/18 19:35 20m sidharthseela@gmail.com patch upstream report log

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in ntfs_dir_emit fs/ntfs3/dir.c:335 [inline]
BUG: KMSAN: uninit-value in ntfs_read_hdr+0xfcc/0x13e0 fs/ntfs3/dir.c:385
 ntfs_dir_emit fs/ntfs3/dir.c:335 [inline]
 ntfs_read_hdr+0xfcc/0x13e0 fs/ntfs3/dir.c:385
 ntfs_readdir+0xf21/0x1a30 fs/ntfs3/dir.c:496
 iterate_dir+0x452/0x620 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0x17e/0x550 fs/readdir.c:396
 __x64_sys_getdents64+0x97/0xe0 fs/readdir.c:396
 x64_sys_call+0x3a14/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:218
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 ntfs_write_bh+0x6ae/0xe90 fs/ntfs3/fsntfs.c:1430
 indx_write fs/ntfs3/index.c:1027 [inline]
 indx_insert_into_buffer+0x287/0x2010 fs/ntfs3/index.c:1809
 indx_insert_entry+0xcde/0x1050 fs/ntfs3/index.c:1986
 ni_add_name+0xef7/0x11e0 fs/ntfs3/frecord.c:2995
 ntfs_link_inode+0x221/0x350 fs/ntfs3/inode.c:1728
 ntfs_link+0x20e/0x500 fs/ntfs3/namei.c:146
 vfs_link+0x8eb/0xb30 fs/namei.c:4854
 do_linkat+0x4af/0x1040 fs/namei.c:4924
 __do_sys_link fs/namei.c:4958 [inline]
 __se_sys_link fs/namei.c:4956 [inline]
 __x64_sys_link+0xd7/0x140 fs/namei.c:4956
 x64_sys_call+0x162f/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:87
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 hdr_insert_de+0x4c8/0x550 fs/ntfs3/index.c:838
 indx_insert_into_buffer+0x1b6/0x2010 fs/ntfs3/index.c:1805
 indx_insert_entry+0xcde/0x1050 fs/ntfs3/index.c:1986
 ni_add_name+0xef7/0x11e0 fs/ntfs3/frecord.c:2995
 ntfs_link_inode+0x221/0x350 fs/ntfs3/inode.c:1728
 ntfs_link+0x20e/0x500 fs/ntfs3/namei.c:146
 vfs_link+0x8eb/0xb30 fs/namei.c:4854
 do_linkat+0x4af/0x1040 fs/namei.c:4924
 __do_sys_link fs/namei.c:4958 [inline]
 __se_sys_link fs/namei.c:4956 [inline]
 __x64_sys_link+0xd7/0x140 fs/namei.c:4956
 x64_sys_call+0x162f/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:87
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4197 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_noprof+0x81b/0xec0 mm/slub.c:4247
 ntfs_link_inode+0x90/0x350 fs/ntfs3/inode.c:1716
 ntfs_link+0x20e/0x500 fs/ntfs3/namei.c:146
 vfs_link+0x8eb/0xb30 fs/namei.c:4854
 do_linkat+0x4af/0x1040 fs/namei.c:4924
 __do_sys_link fs/namei.c:4958 [inline]
 __se_sys_link fs/namei.c:4956 [inline]
 __x64_sys_link+0xd7/0x140 fs/namei.c:4956
 x64_sys_call+0x162f/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:87
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 5963 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
=====================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/17 13:03 upstream 5aca7966d2a7 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ntfs_read_hdr
2026/01/02 16:48 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ntfs_read_hdr
2026/01/02 08:24 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ntfs_read_hdr
2025/11/11 04:57 upstream 4ea7c1717f3f 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ntfs_read_hdr
2025/11/11 04:56 upstream 4ea7c1717f3f 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ntfs_read_hdr
2025/09/17 00:44 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ntfs_read_hdr
* Struck through repros no longer work on HEAD.