From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+7e6ee55011deeebce15d@syzkaller.appspotmail.com, Takashi Iwai Subject: [PATCH 3.18 04/52] ALSA: pcm: Remove yet superfluous WARN_ON() Date: Mon, 29 Jan 2018 13:56:22 +0100 Message-Id: <20180129123628.379224554@linuxfoundation.org> In-Reply-To: <20180129123628.168904217@linuxfoundation.org> References: <20180129123628.168904217@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit 23b19b7b50fe1867da8d431eea9cd3e4b6328c2c upstream. muldiv32() contains a snd_BUG_ON() (which is morphed as WARN_ON() with debug option) for checking the case of 0 / 0. This would be helpful if this happens only as a logical error; however, since the hw refine is performed with any data set provided by user, the inconsistent values that can trigger such a condition might be passed easily. Actually, syzbot caught this by passing some zero'ed old hw_params ioctl. So, having snd_BUG_ON() there is simply superfluous and rather harmful to give unnecessary confusions. Let's get rid of it. Reported-by: syzbot+7e6ee55011deeebce15d@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/pcm_lib.c | 1 - 1 file changed, 1 deletion(-) --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -644,7 +644,6 @@ static inline unsigned int muldiv32(unsi { u_int64_t n = (u_int64_t) a * b; if (c == 0) { - snd_BUG_ON(!n); *r = 0; return UINT_MAX; }