From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f199.google.com (mail-il1-f199.google.com [209.85.166.199]) (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 A55D06110 for ; Sun, 25 Feb 2024 03:59:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708833584; cv=none; b=eenlE/Asj/kCMeHSOQuD7lfnMjpxLNKv/6EiaD/qbg684K3g5Pm4QT9P8gQWoIF+ALlex90LxtNE9Zg6iIc2hwdXdGRlygbzV8i12rmm6FS3JamKGaD2C9RjTA1Fl4xl0efjILLAbPD5rSjrPRYXZb/Xzi0mzFwyRjcs9Eokzqk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708833584; c=relaxed/simple; bh=MUsdO6w7ERvP2PkLq4b3h828tT6GKDziyED4AzcUEJc=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=GVXr9YKho/rIRD+6L5H16370SK65lvqbKrJo3fgspBDJ97T8tMsCj2ulY1+1iBh56prxhAGcspc1LUTjJXgoUM9VishISI5Mx5zHHB1ZD8cm6sGsqhvfNACDFuPEp6OiPtbm6eznGAWEXmfOWz9cI3ddNG13KzdZ3xovBJA1Xdk= 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=209.85.166.199 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-il1-f199.google.com with SMTP id e9e14a558f8ab-3652275e581so19635695ab.3 for ; Sat, 24 Feb 2024 19:59:42 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708833582; x=1709438382; 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=8Cg4O/UrkhasJYvwgjNZJ6K6JARSDn+LYxb+PQ32Q3I=; b=dkdlbl0QkL4AjzXom6/Q0HkfV4+yqdG4sDpBY7zv+sKcWghDLrVeYv2RgVEPUBt5CV K3V2yhKIKj3sZNhRCQvmoAjgKqtENj3Zvwq5lRPMEk3UFHAqdqQAqDFf0Fwlf5+MyFer YotBaHiunDSfWXY+wUWznCEntZUf2UGXVGT7Z+f4sj0GG5NSgfoklDi2BlMKoNML23Q1 veStl/STys7Fcz+mPxfQIJ0dy85IOMeFYCtd+b3Bz+8b1NyVDwZ4XIngk88AvIxuz/p/ INx8Jv9scZ5ICxuwfXo44UF3qe8pKwpqaIB2smJAGdWlxKOl8fI6P1/YPb9rRlj/J/cw aZlg== X-Gm-Message-State: AOJu0Yzb+4R53Y2Fj8g28EGu3erbvHA9EtkqS69Fb1PlmM/y1pJE6XS0 gBDn++9IiLEuScShlrwYeryLq3uEIBIq135EqV8MQ6XWGYqBS95/SIfF9w7VDsj2fBM5+WEhymB +EAaRxBUpUtTWbmSngRLeGHCbvJydNRQiFg1WWaeLLoQliz24NeMbuEohxA== X-Google-Smtp-Source: AGHT+IFaIcgPNhoH5vx+m4lcsKPx+gR3Tdm4UkceB/ydTgFuCPeNNGAP47cABHty2xriHNnA6ii/Wwn8i7r4PZ1gysO7Zrm2enXv Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:20ec:b0:365:3088:eae6 with SMTP id q12-20020a056e0220ec00b003653088eae6mr323765ilv.6.1708833581902; Sat, 24 Feb 2024 19:59:41 -0800 (PST) Date: Sat, 24 Feb 2024 19:59:41 -0800 In-Reply-To: <000000000000fd588e060de27ef4@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000a1340206122cd249@google.com> Subject: Re: [syzbot] Re: [syzbot] [virtualization?] KMSAN: uninit-value in virtqueue_add (4) From: syzbot To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org. *** Subject: Re: [syzbot] [virtualization?] KMSAN: uninit-value in virtqueue_add (4) Author: penguin-kernel@i-love.sakura.ne.jp #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git v6.7 syzbot is reporting a false-positive KMSAN warning upon coredump, for dump_emit_page() path reaches memcpy_from_iter_mc() via iterate_bvec() by setting "struct iov_iter"->copy_mc to true. Make arch/x86/lib/copy_mc.c not to call arch/x86/lib/copy_mc_64.S when KMSAN is enabled. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=d7521c1e3841ed075a42 Signed-off-by: Tetsuo Handa --- arch/x86/lib/copy_mc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c index 6e8b7e600def..c6a0b8dbf58d 100644 --- a/arch/x86/lib/copy_mc.c +++ b/arch/x86/lib/copy_mc.c @@ -61,9 +61,9 @@ unsigned long copy_mc_enhanced_fast_string(void *dst, const void *src, unsigned */ unsigned long __must_check copy_mc_to_kernel(void *dst, const void *src, unsigned len) { - if (copy_mc_fragile_enabled) + if (!IS_ENABLED(CONFIG_KMSAN) && copy_mc_fragile_enabled) return copy_mc_fragile(dst, src, len); - if (static_cpu_has(X86_FEATURE_ERMS)) + if (!IS_ENABLED(CONFIG_KMSAN) && static_cpu_has(X86_FEATURE_ERMS)) return copy_mc_enhanced_fast_string(dst, src, len); memcpy(dst, src, len); return 0; @@ -74,14 +74,14 @@ unsigned long __must_check copy_mc_to_user(void __user *dst, const void *src, un { unsigned long ret; - if (copy_mc_fragile_enabled) { + if (!IS_ENABLED(CONFIG_KMSAN) && copy_mc_fragile_enabled) { __uaccess_begin(); ret = copy_mc_fragile((__force void *)dst, src, len); __uaccess_end(); return ret; } - if (static_cpu_has(X86_FEATURE_ERMS)) { + if (!IS_ENABLED(CONFIG_KMSAN) && static_cpu_has(X86_FEATURE_ERMS)) { __uaccess_begin(); ret = copy_mc_enhanced_fast_string((__force void *)dst, src, len); __uaccess_end(); -- 2.34.1