syzbot


WARNING in ntfs_extend_initialized_size (2)

Status: upstream: reported C repro on 2026/02/15 20:54
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+2bd8e813c7f767aa9bb1@syzkaller.appspotmail.com
Fix commit: 10d7c95af043 fs/ntfs3: add delayed-allocation (delalloc) support
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce 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-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-gce-arm64]
First crash: 5d17h, last: 5d08h
Cause bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH v2] fs/ntfs3: add delayed-allocation (delalloc) support 1 (1) 2026/02/16 16:26
[syzbot] [ntfs3?] WARNING in ntfs_extend_initialized_size (2) 0 (1) 2026/02/15 20:54
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in ntfs_extend_initialized_size -1 1 371d 371d 0/3 auto-obsoleted due to no activity on 2025/05/24 21:40
upstream WARNING in ntfs_extend_initialized_size ntfs3 -1 C inconclusive inconclusive 4 458d 502d 28/29 fixed on 2025/06/10 16:19

Sample crash report:
loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
is_compressed(ni)
WARNING: fs/ntfs3/file.c:236 at ntfs_extend_initialized_size+0x1dc/0x210 fs/ntfs3/file.c:236, CPU#0: syz.0.17/5995
Modules linked in:
CPU: 0 UID: 0 PID: 5995 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ntfs_extend_initialized_size+0x1dc/0x210 fs/ntfs3/file.c:236
Code: 0d ff 4c 89 33 31 ed eb 05 e8 20 6b a3 fe 89 e8 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d e9 cb a1 8e 08 cc e8 05 6b a3 fe 90 <0f> 0b 90 e9 31 ff ff ff 89 d1 80 e1 07 80 c1 03 38 c1 0f 8c e1 fe
RSP: 0018:ffffc90003667c30 EFLAGS: 00010293
RAX: ffffffff8322375b RBX: ffff88805c1f1670 RCX: ffff8880300f9e40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000800 R08: ffff88805c1f1737 R09: 1ffff1100b83e2e6
R10: dffffc0000000000 R11: ffffed100b83e2e7 R12: 0000000000000012
R13: 0000000000000fee R14: 1ffff1100b83e2ce R15: 0000000000000000
FS:  000055556ac47500(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f963fff CR3: 000000007a426000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ntfs_fallocate+0xf21/0x1220 fs/ntfs3/file.c:670
 vfs_fallocate+0x669/0x7e0 fs/open.c:340
 ksys_fallocate fs/open.c:364 [inline]
 __do_sys_fallocate fs/open.c:369 [inline]
 __se_sys_fallocate fs/open.c:367 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f248b59bf79
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:00007ffdfe289018 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f248b815fa0 RCX: 00007f248b59bf79
RDX: 0000000000000fff RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f248b6327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f248b815fac R14: 00007f248b815fa0 R15: 00007f248b815fa0
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/15 03:50 linux-next 635c467cc14e 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
2026/02/15 03:17 linux-next 635c467cc14e 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
2026/02/15 02:50 linux-next 635c467cc14e 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
2026/02/15 11:38 linux-next 635c467cc14e 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
2026/02/15 02:58 linux-next 635c467cc14e 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
2026/02/15 02:17 linux-next 635c467cc14e 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
2026/02/15 02:17 linux-next 635c467cc14e 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in ntfs_extend_initialized_size
* Struck through repros no longer work on HEAD.