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 80C66224EF for ; Fri, 3 Nov 2023 18:33:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FyM320pe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E749C433CA; Fri, 3 Nov 2023 18:33:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1699036417; bh=GCcviAr0J+IVeM1/p5MQ4ex6AHZgCCmGit6AtH3K05k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FyM320peA+QJM3iwPOVx6aexI+At1jmo+xGow9tXL1dH6z/biHMdoS+afNaGl1mSa H559T8yRhyt/BtwSnyLPNC+nzAAPis18jy9AaJTiXUw12ij6GM5PApK80g7lY7mcT/ rxtzhYNEuT14oqiJl2oi5vH8irjBNVvM2kjqmum0= Date: Fri, 3 Nov 2023 19:33:34 +0100 From: Greg KH To: Justin Chen Cc: Yuran Pereira , davem@davemloft.net, netdev@vger.kernel.org, florian.fainelli@broadcom.com, linux-kernel@vger.kernel.org, edumazet@google.com, bcm-kernel-feedback-list@broadcom.com, kuba@kernel.org, pabeni@redhat.com, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH] Prevent out-of-bounds read/write in bcmasp_netfilt_rd and bcmasp_netfilt_wr Message-ID: <2023110318-utensil-figure-eb80@gregkh> References: <2023110301-purist-reputable-fab7@gregkh> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Nov 03, 2023 at 11:23:16AM -0700, Justin Chen wrote: > > > On 11/3/23 5:57 AM, Greg KH wrote: > > On Fri, Nov 03, 2023 at 05:57:48PM +0530, Yuran Pereira wrote: > > > The functions `bcmasp_netfilt_rd` and `bcmasp_netfilt_wr` both call > > > `bcmasp_netfilt_get_reg_offset` which, when it fails, returns `-EINVAL`. > > > This could lead to an out-of-bounds read or write when `rx_filter_core_rl` > > > or `rx_filter_core_wl` is called. > > > > > > This patch adds a check in both functions to return immediately if > > > `bcmasp_netfilt_get_reg_offset` fails. This prevents potential out-of-bounds read > > > or writes, and ensures that no undefined or buggy behavior would originate from > > > the failure of `bcmasp_netfilt_get_reg_offset`. > > > > > > Addresses-Coverity-IDs: 1544536 ("Out-of-bounds access") > > > Signed-off-by: Yuran Pereira > > > --- > > > drivers/net/ethernet/broadcom/asp2/bcmasp.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp.c b/drivers/net/ethernet/broadcom/asp2/bcmasp.c > > > index 29b04a274d07..8b90b761bdec 100644 > > > --- a/drivers/net/ethernet/broadcom/asp2/bcmasp.c > > > +++ b/drivers/net/ethernet/broadcom/asp2/bcmasp.c > > > @@ -227,6 +227,8 @@ static void bcmasp_netfilt_wr(struct bcmasp_priv *priv, > > > reg_offset = bcmasp_netfilt_get_reg_offset(priv, nfilt, reg_type, > > > offset); > > > + if (reg_offset < 0) > > > + return; > > > rx_filter_core_wl(priv, val, reg_offset); > > > } > > > @@ -244,6 +246,8 @@ static u32 bcmasp_netfilt_rd(struct bcmasp_priv *priv, > > > reg_offset = bcmasp_netfilt_get_reg_offset(priv, nfilt, reg_type, > > > offset); > > > + if (reg_offset < 0) > > > + return 0; > > > > Shouldn't you return an error here? > > > > thanks > > > > greg k-h > > As long as offset is less than MAX_WAKE_FILTER_SIZE we don't need to worry > about error checking. This is already checked before we call > netfilt_get_reg_offset() in both cases. Instead of returning -EINVAL in > neffilt_get_reg_offset() lets return 0. This will silence the coverity > check. In practice we will never hit this logic. Then don't change it, coverity is incorrect here. greg k-h