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KMSAN: uninit-value in longest_match_std (2)

Status: upstream: reported C repro on 2024/01/09 18:17
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+08d8956768c96a2c52cf@syzkaller.appspotmail.com
Fix commit: fs/ntfs3: Initialize new folios before use
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 764d, last: 4h58m
▶ ▼ Discussions (20)
Title Replies (including bot) Last reply
[syzbot] Monthly ntfs3 report (Dec 2025) 0 (1) 2025/12/29 08:11
[PATCH] fs/ntfs3: Initialize new folios before use 2 (2) 2025/12/09 13:37
[syzbot] [ntfs3?] KMSAN: uninit-value in longest_match_std (2) 0 (3) 2025/11/19 14:24
[syzbot] Monthly ntfs3 report (Oct 2025) 0 (1) 2025/10/27 08:42
[syzbot] Monthly ntfs3 report (Sep 2025) 0 (1) 2025/09/25 16:00
[syzbot] Monthly ntfs3 report (Aug 2025) 0 (1) 2025/08/25 13:19
[syzbot] Monthly ntfs3 report (Jul 2025) 0 (1) 2025/07/25 12:39
[syzbot] Monthly ntfs3 report (Jun 2025) 0 (1) 2025/06/24 07:38
[syzbot] Monthly ntfs3 report (May 2025) 0 (1) 2025/05/24 10:04
[syzbot] Monthly ntfs3 report (Apr 2025) 0 (1) 2025/04/22 12:41
[syzbot] Monthly ntfs3 report (Mar 2025) 0 (1) 2025/03/18 14:49
Re: [syzbot] [ntfs3?] KMSAN: uninit-value in longest_match_std (2) 1 (2) 2025/02/03 08:14
[syzbot] Monthly ntfs3 report (Jan 2025) 0 (1) 2025/01/15 08:54
[syzbot] Monthly ntfs3 report (Dec 2024) 0 (1) 2024/12/16 09:44
[syzbot] Monthly ntfs3 report (Nov 2024) 0 (1) 2024/11/13 11:07
[syzbot] Monthly ntfs3 report (Jun 2024) 0 (1) 2024/06/10 12:41
[syzbot] Monthly ntfs3 report (May 2024) 0 (1) 2024/05/06 13:18
[syzbot] Monthly ntfs3 report (Apr 2024) 0 (1) 2024/04/05 12:38
[syzbot] Monthly ntfs3 report (Mar 2024) 0 (1) 2024/03/05 11:09
[syzbot] Monthly ntfs3 report (Feb 2024) 0 (1) 2024/02/02 21:04
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in longest_match_std ntfs3 7 1360 836d 944d 0/29 auto-obsoleted due to no activity on 2023/12/09 02:47
upstream KMSAN: kernel-infoleak in _copy_to_iter (7) net 23 C 138977 1074d 1426d 22/29 fixed on 2023/02/24 13:50
upstream KMSAN: uninit-value in __crc32c_le_base (2) crypto 7 C 6207 1036d 2108d 0/29 closed as invalid on 2023/04/06 23:31
upstream KMSAN: kernel-infoleak in _copy_to_iter (8) mm 23 C 21180 970d 1064d 22/29 fixed on 2023/06/08 14:41
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/11/19 14:24 28m kubik.bartlomiej@gmail.com patch upstream OK log
2025/02/03 07:29 28m gauthamgujjula@gmail.com patch upstream error
2025/01/29 05:28 5h12m gauthamgujjula@gmail.com patch upstream error
2024/09/07 20:13 28m retest repro upstream OK log
2024/09/07 20:13 33m retest repro upstream OK log
2024/08/05 19:45 27m retest repro upstream OK log
2024/08/05 19:45 27m retest repro upstream OK log
2024/08/05 19:45 30m retest repro upstream OK log
2024/06/29 19:30 22m retest repro upstream error
2024/06/29 19:30 22m retest repro upstream error

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in get_match_len fs/ntfs3/lznt.c:43 [inline]
BUG: KMSAN: uninit-value in longest_match_std+0x56e/0xe00 fs/ntfs3/lznt.c:64
 get_match_len fs/ntfs3/lznt.c:43 [inline]
 longest_match_std+0x56e/0xe00 fs/ntfs3/lznt.c:64
 compress_chunk fs/ntfs3/lznt.c:170 [inline]
 compress_lznt+0x414/0xef0 fs/ntfs3/lznt.c:339
 ni_write_frame+0x1032/0x1e10 fs/ntfs3/frecord.c:2779
 ntfs_compress_write+0x265e/0x3a20 fs/ntfs3/file.c:1172
 ntfs_file_write_iter+0x9e9/0xfc0 fs/ntfs3/file.c:1286
 aio_write+0x72b/0x9d0 fs/aio.c:1633
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x283f/0x3280 fs/aio.c:2052
 __do_sys_io_submit fs/aio.c:2111 [inline]
 __se_sys_io_submit+0x275/0x700 fs/aio.c:2081
 __x64_sys_io_submit+0x96/0xe0 fs/aio.c:2081
 x64_sys_call+0xbed/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:210
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __alloc_frozen_pages_noprof+0x6a0/0xe30 mm/page_alloc.c:5005
 alloc_pages_mpol+0x4cd/0x890 mm/mempolicy.c:2301
 alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
 alloc_pages_noprof mm/mempolicy.c:2392 [inline]
 folio_alloc_noprof+0x1dc/0x350 mm/mempolicy.c:2402
 filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1007
 __filemap_get_folio+0xb40/0x18e0 mm/filemap.c:1969
 ntfs_get_frame_pages+0xd8/0x6b0 fs/ntfs3/file.c:964
 ntfs_compress_write+0x1cd5/0x3a20 fs/ntfs3/file.c:1120
 ntfs_file_write_iter+0x9e9/0xfc0 fs/ntfs3/file.c:1286
 aio_write+0x72b/0x9d0 fs/aio.c:1633
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x283f/0x3280 fs/aio.c:2052
 __do_sys_io_submit fs/aio.c:2111 [inline]
 __se_sys_io_submit+0x275/0x700 fs/aio.c:2081
 __x64_sys_io_submit+0x96/0xe0 fs/aio.c:2081
 x64_sys_call+0xbed/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:210
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 5815 Comm: syz-executor226 Not tainted 6.15.0-rc2-syzkaller-00087-gcfb2e2c57aef #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
=====================================================

Crashes (23498):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/17 19:54 upstream cfb2e2c57aef 2a6ededb .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2025/01/07 07:46 upstream fbfd64d25c7a f3558dbf .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2024/09/29 05:43 upstream 3efc57369a0c ba29ff75 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2024/07/21 23:31 upstream 2c9b3512402e b88348e9 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2024/07/21 21:07 upstream 2c9b3512402e b88348e9 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2024/07/21 15:24 upstream 2c9b3512402e b88348e9 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2024/04/12 02:09 upstream e8c39d0f57f3 478efa7f .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2024/01/02 15:04 upstream 610a9b8f49fb fb427a07 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/02 19:48 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/02 17:13 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/02 15:28 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 23:29 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 23:25 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 22:09 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 20:11 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 18:56 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 17:18 upstream 162b42445b58 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/01 01:38 upstream ad9a728a3388 35764559 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/31 16:49 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/31 13:11 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/31 11:58 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/31 08:48 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/31 08:48 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/31 01:25 upstream 4d310797262f e01a0ca6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 22:28 upstream 4d310797262f e01a0ca6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 16:26 upstream 4d310797262f bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 13:06 upstream 4d310797262f bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 05:13 upstream 4d310797262f bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 05:12 upstream 4d310797262f bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 02:22 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/30 01:21 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 22:39 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 20:12 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 16:35 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 12:28 upstream 8dfce8991b95 b78a7341 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 11:24 upstream 8dfce8991b95 b78a7341 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 09:39 upstream 8dfce8991b95 b78a7341 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/29 04:37 upstream 8dfce8991b95 b78a7341 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/28 23:15 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/28 20:11 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/28 17:11 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/28 15:40 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/28 14:32 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/01/28 08:26 upstream 1f97d9dcf536 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in longest_match_std
2026/02/02 06:07 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/02/01 02:55 upstream ad9a728a3388 35764559 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/31 17:21 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/31 14:36 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/30 10:28 upstream 4d310797262f bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/29 23:46 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/29 23:45 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/29 21:30 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/29 10:03 upstream 8dfce8991b95 b78a7341 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/28 21:33 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2026/01/28 18:31 upstream 1f97d9dcf536 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
2023/12/31 06:39 upstream 453f5db0619e fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in longest_match_std
* Struck through repros no longer work on HEAD.