From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1390BA48 for ; Tue, 7 Mar 2023 18:21:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38B07C433EF; Tue, 7 Mar 2023 18:21:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678213260; bh=/me9iKM75L4B1Dtkg8HfOMa6QxGRKBHDld9zfDffo7g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d1tb3tqyP84APhbxvtwpJqaItqNwA2tJpzQo05QNNYWPP6gsGELV0C/SVR8dw2PwP Ge59ndFiU2moTXbC3uCM2IuZnjImXypiGLZMpeTk78ZTBrPf+IgUX/AWcLbuwAVVho S5SBiLaT+EoXB/uGJ3d8OlxLj0HqpaFabWTo45Ks= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christophe JAILLET , Sasha Levin Subject: [PATCH 6.1 451/885] usb: early: xhci-dbc: Fix a potential out-of-bound memory access Date: Tue, 7 Mar 2023 17:56:25 +0100 Message-Id: <20230307170022.083999957@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170001.594919529@linuxfoundation.org> References: <20230307170001.594919529@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Christophe JAILLET [ Upstream commit a4a97ab3db5c081eb6e7dba91306adefb461e0bd ] If xdbc_bulk_write() fails, the values in 'buf' can be anything. So the string is not guaranteed to be NULL terminated when xdbc_trace() is called. Reserve an extra byte, which will be zeroed automatically because 'buf' is a static variable, in order to avoid troubles, should it happen. Fixes: aeb9dd1de98c ("usb/early: Add driver for xhci debug capability") Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/d6a7562c5e839a195cee85db6dc81817f9372cb1.1675016180.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/early/xhci-dbc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c index bfb7e2b852996..7ef0a4b397620 100644 --- a/drivers/usb/early/xhci-dbc.c +++ b/drivers/usb/early/xhci-dbc.c @@ -874,7 +874,8 @@ static int xdbc_bulk_write(const char *bytes, int size) static void early_xdbc_write(struct console *con, const char *str, u32 n) { - static char buf[XDBC_MAX_PACKET]; + /* static variables are zeroed, so buf is always NULL terminated */ + static char buf[XDBC_MAX_PACKET + 1]; int chunk, ret; int use_cr = 0; -- 2.39.2