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AJvYcCXYNu6heXLXAiR3x6H2Aa3UDsD9sH3CZ/UQbDvkNjlMIfIcPVbTZJ8qlsba9Zma/7LSn9eay075jHfzm7Y=@vger.kernel.org X-Gm-Message-State: AOJu0YzOpo9kCWwtu5d57cuf6UQ8meGhr70BRGebUh+A3yYb268Pfc6v ZfUoLsNW77TPb7a8Tdzei3lNeJKP/vt5s4sQ4uNBJlM1AvqLy8ZvbyJapw/Tjw6Tb98TQ/syVzd jZtOM7PzpO6q6exCF1C+Z+++H5h55AFQwCSTQ9CoWyFdQWoObDcaJWe+G5xQ= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:8188:b0:65c:2501:6c79 with SMTP id 006d021491bc7-662cab9db87mr2267253eaf.59.1769218042409; Fri, 23 Jan 2026 17:27:22 -0800 (PST) Date: Fri, 23 Jan 2026 17:27:22 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69741ffa.050a0220.1a75db.0328.GAE@google.com> Subject: [syzbot] [ext4?] WARNING in ext4_split_convert_extents From: syzbot To: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tytso@mit.edu Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: d08c85ac8894 Add linux-next specific files for 20260119 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=171a1852580000 kernel config: https://syzkaller.appspot.com/x/.config?x=ee3bfbe9e319ed0c dashboard link: https://syzkaller.appspot.com/bug?extid=e625b79bfdd66c067432 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=121533fa580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12bc7b9a580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/94cfdbd8a0c9/disk-d08c85ac.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f7ec0695ac29/vmlinux-d08c85ac.xz kernel image: https://storage.googleapis.com/syzbot-assets/ddc8307e03e3/bzImage-d08c85ac.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/6ddc9a8efbb6/mount_0.gz fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=14f96bfc580000) IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e625b79bfdd66c067432@syzkaller.appspotmail.com ------------[ cut here ]------------ WARNING: fs/ext4/extents.c:3486 at ext4_split_extent fs/ext4/extents.c:3485 [inline], CPU#1: kworker/u8:4/58 WARNING: fs/ext4/extents.c:3486 at ext4_split_convert_extents+0x13c2/0x1a10 fs/ext4/extents.c:3839, CPU#1: kworker/u8:4/58 Modules linked in: CPU: 1 UID: 0 PID: 58 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work RIP: 0010:ext4_split_extent fs/ext4/extents.c:3485 [inline] RIP: 0010:ext4_split_convert_extents+0x13c2/0x1a10 fs/ext4/extents.c:3839 Code: 4c 8b 44 24 38 e8 be 85 fe ff 40 b5 01 4c 8b 64 24 18 49 81 fc 00 f0 ff ff 0f 87 19 ff ff ff e9 4e f0 ff ff e8 3f 8f 4a ff 90 <0f> 0b 90 49 bf 00 00 00 00 00 fc ff df 44 8b 6c 24 04 4c 8b 64 24 RSP: 0018:ffffc900015f7328 EFLAGS: 00010293 RAX: ffffffff82768aa1 RBX: dffffc0000000001 RCX: ffff88801cb99e40 RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000008 RBP: 0000000000000008 R08: ffff88802ba1269f R09: 0000000000000000 R10: ffff88802ba12690 R11: ffffed10057424d4 R12: 0000000000000010 R13: ffff888073634d01 R14: 0000000000000010 R15: 0000000000000100 FS: 0000000000000000(0000) GS:ffff888125cf2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000080 CR3: 000000000df3e000 CR4: 00000000003526f0 Call Trace: ext4_convert_unwritten_extents_endio fs/ext4/extents.c:3915 [inline] ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3999 [inline] ext4_ext_map_blocks+0xde4/0x5560 fs/ext4/extents.c:4336 ext4_map_create_blocks+0x11d/0x540 fs/ext4/inode.c:616 ext4_map_blocks+0x759/0x1170 fs/ext4/inode.c:809 ext4_convert_unwritten_extents+0x2a8/0x5d0 fs/ext4/extents.c:5038 ext4_convert_unwritten_io_end_vec+0xff/0x170 fs/ext4/extents.c:5078 ext4_end_io_end+0xc7/0x410 fs/ext4/page-io.c:200 ext4_do_flush_completed_IO fs/ext4/page-io.c:291 [inline] ext4_end_io_rsv_work+0x262/0x330 fs/ext4/page-io.c:306 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x389/0x480 kernel/kthread.c:467 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup