From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f70.google.com (mail-oo1-f70.google.com [209.85.161.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A296A368284 for ; Fri, 6 Mar 2026 06:36:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772778981; cv=none; b=VbIhB+cDdDDcMJI/Z1v5ZY4BFuVwSYGbvP9nbsk2nI594mltPVXh0u4uM5W3ihz2cnYjys8SNbVjM3fJUyLufpZKAGU1+C4g4tw0MiRE9KM1QeT7rtaMhBqSiNNgecEZHDXlSATVOqUiyyIa2doyrmjo3L9EnWJgAbdHUQQ/A5M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772778981; c=relaxed/simple; bh=vOFWcD9VgS+J2CrjRSLI6m6RzJjvI4JzAWbvcLw4kfw=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=koNFrZEw6Mqo9bY4rC4jZrqym8OlAbUXdklI3qRA8MQP5S9IRZQTFTZAxjsYnpIBBK5zHRfVGOaZaGd3osz8JlveBrKmZgKIEtEA2Ss920LLKponYbXhZ8ikF5brvLWtorEorCM0lluoPhLp7YGLoOrenr/Qejf05xiAXQZe5mE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f70.google.com with SMTP id 006d021491bc7-679dda090fbso151536533eaf.2 for ; Thu, 05 Mar 2026 22:36:19 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772778979; x=1773383779; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=xjCUsjN0/IVVP3mFuyWfmY85swmEI0tCp3uwii5R7sU=; b=p3Jyfa3Zy+oDD2hd/aCTHaV6aXLhlW/32TdRr1GRvwJ6aZ2h/nJRxTSx64YWXn3sL0 Z2IyQOf33LXb/Xs01mj20PIyiQMzDH37vmyL1CYL2eX1atK7ZRC2SNqUPtx4CyD+jWgK kqHjtent/yEXFBglTGUiKG5WkfxKj3J02IEiVhGYfkvBvIi3e9msgIWKjEZ/lPRtSs0T 5h4+64+OujeEwBQdfrSD9bbwYzbFx3QrBaJY0PxTCk0QPdcIzexdzocy7t6RtzkDXqTX XiKYeh9tj+5B4q5T8dLtY/Ch79tdqzUv+Y7tvEGrYnxDkqqyYHZEeNazeg0SEyFGsHv0 tO5Q== X-Forwarded-Encrypted: i=1; AJvYcCWEEd4ke35jGaqURDRjeJd6vqola5yRf9OfvWtG08VHGeOTRGQpZjIzg2Ec6n+P9Mhx/O4/Sw==@lists.linux.dev X-Gm-Message-State: AOJu0YzFKw8DE82wU4qQ04j2HEoOTWrdQIk+xyCOCej6SpfaG+CVtdIh dUXTcZ57iBj9G28CpPOLHI5zCusTY3Ugj7cF+/rcExoAMkc71nwzwQuLlkP99JDtWngM9JbPEdV FRCbkDpqDCCKxS/9+EpDgvWXMhmG8ubFl//nxTKDdmcHxYMx1aFLwqidHCfM= Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1607:b0:663:40d:4893 with SMTP id 006d021491bc7-67b9bc4f053mr834261eaf.3.1772778978736; Thu, 05 Mar 2026 22:36:18 -0800 (PST) Date: Thu, 05 Mar 2026 22:36:18 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69aa75e2.050a0220.13f275.000f.GAE@google.com> Subject: [syzbot] [netfs?] kernel BUG in netfs_limit_iter From: syzbot To: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, netfs@lists.linux.dev, pc@manguebit.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: c107785c7e8d Merge tag 'modules-7.0-rc3.fixes' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13d408ba580000 kernel config: https://syzkaller.appspot.com/x/.config?x=976ba5a93c4add9e dashboard link: https://syzkaller.appspot.com/bug?extid=9c058f0d63475adc97fd compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16421552580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=166a97e6580000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-c107785c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/3a4a4abcd973/vmlinux-c107785c.xz kernel image: https://storage.googleapis.com/syzbot-assets/f60667f16840/bzImage-c107785c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9c058f0d63475adc97fd@syzkaller.appspotmail.com ------------[ cut here ]------------ kernel BUG at fs/netfs/iterator.c:248! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 3 UID: 0 PID: 6437 Comm: syz.9.39 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:netfs_limit_iter+0x100d/0x1100 fs/netfs/iterator.c:248 Code: ff e9 a4 f4 ff ff 48 89 de 48 c7 c7 a0 db ab 8e e8 e8 3f 74 fe e9 59 f6 ff ff e8 9e e8 b1 ff e9 6f f6 ff ff e8 74 6b 45 ff 90 <0f> 0b e8 fc e7 b1 ff e9 cd f9 ff ff 4c 89 f6 48 c7 c7 20 dc ab 8e RSP: 0018:ffffc900040e6d18 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff82c3391b RDX: ffff8880298a0000 RSI: ffffffff82c3484c RDI: ffff8880298a0000 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000005 R10: 0000000000000003 R11: 0000000000000012 R12: 000000007fffffff R13: 1ffff9200081cda9 R14: ffff88801c7f3960 R15: ffff888022886580 FS: 000055556085f500(0000) GS:ffff8880d6644000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c008fdc000 CR3: 000000002f279000 CR4: 0000000000352ef0 Call Trace: netfs_unbuffered_write+0x25d/0x2080 fs/netfs/direct_write.c:128 netfs_unbuffered_write_iter_locked+0x801/0xab0 fs/netfs/direct_write.c:287 netfs_unbuffered_write_iter+0x40c/0x710 fs/netfs/direct_write.c:377 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:409 __kernel_write_iter+0x2ac/0x920 fs/read_write.c:621 __kernel_write+0xf6/0x140 fs/read_write.c:641 __dump_emit fs/coredump.c:1221 [inline] dump_emit+0x21f/0x330 fs/coredump.c:1259 elf_core_dump+0x2127/0x3d10 fs/binfmt_elf.c:2062 coredump_write fs/coredump.c:1050 [inline] do_coredump fs/coredump.c:1127 [inline] vfs_coredump+0x27bc/0x5570 fs/coredump.c:1201 get_signal+0x1f2a/0x21e0 kernel/signal.c:3019 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x1f8/0x670 kernel/entry/common.c:219 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 002b:0000200000000088 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f5120e15fa0 RCX: 00007f5120b9c799 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000000000008000 RBP: 00007f5120c32bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f5120e15fac R14: 00007f5120e15fa0 R15: 00007f5120e15fa0 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:netfs_limit_iter+0x100d/0x1100 fs/netfs/iterator.c:248 Code: ff e9 a4 f4 ff ff 48 89 de 48 c7 c7 a0 db ab 8e e8 e8 3f 74 fe e9 59 f6 ff ff e8 9e e8 b1 ff e9 6f f6 ff ff e8 74 6b 45 ff 90 <0f> 0b e8 fc e7 b1 ff e9 cd f9 ff ff 4c 89 f6 48 c7 c7 20 dc ab 8e RSP: 0018:ffffc900040e6d18 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff82c3391b RDX: ffff8880298a0000 RSI: ffffffff82c3484c RDI: ffff8880298a0000 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000005 R10: 0000000000000003 R11: 0000000000000012 R12: 000000007fffffff R13: 1ffff9200081cda9 R14: ffff88801c7f3960 R15: ffff888022886580 FS: 000055556085f500(0000) GS:ffff8880d6644000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c008fdc000 CR3: 000000002f279000 CR4: 0000000000352ef0 --- 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