From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 D17F337AA8B for ; Sat, 7 Mar 2026 07:40:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772869205; cv=none; b=qQjOtRP/U9c+icKGjwttJfS4J99uO1MP3z8UBaeVV7GlbTKjMezIiHKoVne9g0aOqKOWL38zSPEqHEp1kHgexndkmicsxTJRT5xeAuqulGHHA5i/wb8/A3gcoBu0u/0gjmzxwxoFNp2sYuueSYMP3O90ASOQ4TuQBOYA7VtCpMQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772869205; c=relaxed/simple; bh=7d8xXkRHbp7AGgyAKujJfBWcaTQ8Y2/aB4Dufx+bUrA=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=eEOxPxu7inXhc7p48z/A0fvMinAw+8XxWFk0Nlio819oSnJABLoex5Wt2LHcTxX70BUZKrEYcYH6XJTc7FSBNZDB41+tWuVxh7Zuot8ueYLCf7w26tvomq7vJH9ecCPLLv49l1ennNVqWCkcyfIF6JuDGM58bpTNI4GRLXcLcgw= 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=209.85.161.71 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-f71.google.com with SMTP id 006d021491bc7-67ba7fa931eso637953eaf.0 for ; Fri, 06 Mar 2026 23:40:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772869203; x=1773474003; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=s54ZIRp1Zm/GdN2LwjSQDuvysuLG2BhkNXS3/XGuhRk=; b=iTB6A+xn2nb79cEnA3FVJAT2Gp62wbMFOKNZ7D/YUexv66ZexbPmjdPXJSzQ85q+wN iJS4Kj25r1aXkC8Nx0a3CuABcggi0dZMuACj9k9mapDrj0BqvZau4C3Tb4pUjV4/q+qm p1dhQSlu2SfTWRsM0WrWMowG+lZLiXwONcoPlz8oRt8l0h/vnNZLmo5DUZK74snRKUMx xOGj7jPC3bB9VLYtmV3uDFFtOCLSRvzL5VCLIOh1/Fl6MGEPilA9tjfBf8a7Gnlx4M8B Dhkiu1tmhSmOdYbqM3cZCiWQnylI4pDAXRZfbLx59/Ug/psFQYcgGHA3Rk5KPohhCEmf x/jg== X-Forwarded-Encrypted: i=1; AJvYcCWtqjAGSced+dsfyoE6QjPZxd9L1ZJKC+gZ5sYOwDyPDZduk33X4zEhIimc4/IMZBTRU/94Fw==@lists.linux.dev X-Gm-Message-State: AOJu0Yz330j2jXvnaHYuUfzI5nhVkX0VcbMx0F1F27AeYB+GdfVshKYQ NSH/8r2nuDc/x3raHjWec6IOXxKQph8+xngDydT5Y/5KOF1HhTVqGp2iUU998Ga3IVxIgenGMDz 7OnAYYAb7uIRbxiiTIMMd/+p2f7nKVejeqWMLQZ6pS6/CVxkuNNDnKWHX00k= Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:2297:b0:67a:555:f8b4 with SMTP id 006d021491bc7-67b9bcc7005mr3068349eaf.34.1772869202834; Fri, 06 Mar 2026 23:40:02 -0800 (PST) Date: Fri, 06 Mar 2026 23:40:02 -0800 In-Reply-To: <675769.1772868400@warthog.procyon.org.uk> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69abd652.050a0220.13f275.0041.GAE@google.com> Subject: Re: [syzbot] [netfs?] kernel BUG in netfs_limit_iter From: syzbot To: dhowells@redhat.com, kartikey406@gmail.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 has tested the proposed patch but the reproducer is still triggering an issue: kernel BUG in netfs_limit_iter ------------[ cut here ]------------ kernel BUG at fs/netfs/iterator.c:248! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 6595 Comm: syz.0.28 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 d8 3d 74 fe e9 59 f6 ff ff e8 8e e6 b1 ff e9 6f f6 ff ff e8 64 69 45 ff 90 <0f> 0b e8 ec e5 b1 ff e9 cd f9 ff ff 4c 89 f6 48 c7 c7 20 dc ab 8e RSP: 0018:ffffc90003c16c70 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff82c33b2b RDX: ffff88802b2aa4c0 RSI: ffffffff82c34a5c RDI: ffff88802b2aa4c0 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000005 R10: 0000000000000003 R11: 0000000000000012 R12: 000000007fffffff R13: 1ffff92000782d94 R14: ffff88802222ef60 R15: ffff8880224b2580 FS: 00007ffbb60b56c0(0000) GS:ffff8880d6444000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffea0531a80 CR3: 000000002ff66000 CR4: 0000000000352ef0 Call Trace: netfs_unbuffered_write+0x2bb/0x2290 fs/netfs/direct_write.c:128 netfs_unbuffered_write_iter_locked+0x801/0xab0 fs/netfs/direct_write.c:295 netfs_unbuffered_write_iter+0x40c/0x710 fs/netfs/direct_write.c:385 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: 00007ffbb5415fa0 RCX: 00007ffbb519c799 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000000000008000 RBP: 00007ffbb5232bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffbb5416038 R14: 00007ffbb5415fa0 R15: 00007ffea05320b8 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 d8 3d 74 fe e9 59 f6 ff ff e8 8e e6 b1 ff e9 6f f6 ff ff e8 64 69 45 ff 90 <0f> 0b e8 ec e5 b1 ff e9 cd f9 ff ff 4c 89 f6 48 c7 c7 20 dc ab 8e RSP: 0018:ffffc90003c16c70 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff82c33b2b RDX: ffff88802b2aa4c0 RSI: ffffffff82c34a5c RDI: ffff88802b2aa4c0 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000005 R10: 0000000000000003 R11: 0000000000000012 R12: 000000007fffffff R13: 1ffff92000782d94 R14: ffff88802222ef60 R15: ffff8880224b2580 FS: 00007ffbb60b56c0(0000) GS:ffff8880d6644000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffea0530cd0 CR3: 000000002ff66000 CR4: 0000000000352ef0 Tested on: commit: c107785c Merge tag 'modules-7.0-rc3.fixes' of git://gi.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git console output: https://syzkaller.appspot.com/x/log.txt?x=103ad8d6580000 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 patch: https://syzkaller.appspot.com/x/patch.diff?x=131ad8d6580000