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 6C86C20DD4D; Fri, 10 Jan 2025 12:58:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736513887; cv=none; b=A5yxqx/ShIQ3r247CjCuuCzQ+cYYmF4RJT7IBV/2ig3UYyvpwo4ROJuutkXQYe8Hnk0jAk992NkyByNpNqRAV6c/plm57/pzIJ8glz3ph2bDfSgdWpWJu38HrAFafhQ52PpLPGyTp3LR1onXrDo4NP/22x0HG82ip6VGElimZrY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736513887; c=relaxed/simple; bh=e3L/+WGmXvI0ne4C9qbIosTkSiE56kAdgAqvv/mzCHo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ryva5k9ur4m9DArew2vL+S7C9e9EsYeXCTonVravY+cKDt9Njc47fgq73Xdb6jUnqs8FxYndEMNLeJVM4If3EZoVVa1q8jc8nsI1JbsqhQphQ0gEMtFS+SoQW4IelDizE2uSmaJigjSTDqXLSLMNHEvFFXTJQAuw2PTkzs3IwAQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A7JLgsx+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A7JLgsx+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8694FC4CED6; Fri, 10 Jan 2025 12:58:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736513887; bh=e3L/+WGmXvI0ne4C9qbIosTkSiE56kAdgAqvv/mzCHo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A7JLgsx+kjR2axR82MuDhFwXiFpJiSAJnvb8fipgbJpPkjsT1PzlMZ3lc2RRcKhxG c2rKde88QouLAO91q2I5CdMJ0+GiT5vzDQiEBULT5v5K1sAgUtj6T0fM2wSvxjHi/d c/j0O74BHcgCvDMz7IkedikwD8tBRveSRuh1ro2rJ//19FQS7+vq5ReLjm61rXLyrU l9a7y7A6iuwFwHGdpj4ADbGiAmIgge/y3kOCkNjPbALMfZa6JUDZbSU5WrIg94uIKY 3PQHsY3k9D+lpTzKUImmwH6oUGBZr9dI32tL9GZ1OXXMC9Q8Uv7xBH0HBW1oWGqO01 QoIx8O4edJSNQ== Date: Fri, 10 Jan 2025 12:58:03 +0000 From: Simon Horman To: Marc Kleine-Budde Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Jimmy Assarsson Subject: Re: [PATCH net-next 15/18] can: kvaser_usb: Update stats and state even if alloc_can_err_skb() fails Message-ID: <20250110125803.GF7706@kernel.org> References: <20250110112712.3214173-1-mkl@pengutronix.de> <20250110112712.3214173-16-mkl@pengutronix.de> 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: <20250110112712.3214173-16-mkl@pengutronix.de> On Fri, Jan 10, 2025 at 12:04:23PM +0100, Marc Kleine-Budde wrote: > From: Jimmy Assarsson > > Ensure statistics, error counters, and CAN state are updated consistently, > even when alloc_can_err_skb() fails during state changes or error message > frame reception. > > Signed-off-by: Jimmy Assarsson > Link: https://patch.msgid.link/20241230142645.128244-1-extja@kvaser.com > Signed-off-by: Marc Kleine-Budde ... > diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c ... > @@ -1187,11 +1169,18 @@ static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev, > if (priv->can.restart_ms && > old_state == CAN_STATE_BUS_OFF && > new_state < CAN_STATE_BUS_OFF) { > - cf->can_id |= CAN_ERR_RESTARTED; > + if (cf) > + cf->can_id |= CAN_ERR_RESTARTED; > netif_carrier_on(priv->netdev); > } > } > > + if (!skb) { > + stats->rx_dropped++; > + netdev_warn(priv->netdev, "No memory left for err_skb\n"); > + return; > + } > + > switch (dev->driver_info->family) { > case KVASER_LEAF: > if (es->leaf.error_factor) { Hi Jimmy and Marc, The next line of this function is: cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; Which dereferences cf. However, the check added at the top of this hunk assumes that cf may be NULL. This doesn't seem consistent. Flagged by Smatch. > -- > 2.45.2 > > >