From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from air.basealt.ru (air.basealt.ru [193.43.8.18]) (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 7930723A9BE; Wed, 16 Apr 2025 11:54:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.43.8.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744804463; cv=none; b=k+6pZP0ng0XEzR41AX1hjpwk6XIaD0/NW89EMkl4JnbLoxH+Dnl2jJUNGMIDFKoR1FLbFHbTSv9RuDrwxyb5q2UjDp2gQxGvkXyWd0ShAYGZdivIJXoRGNgj16LBMoHDy0fWBs5WKu7Iqgd/BjL/AHozBIDptk5ThuADVyZ0Bxc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744804463; c=relaxed/simple; bh=l2wQCuPf45yikHLhbWv39uKEgsRsCbvTGTAouNnyJ7A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ku8XzobcMApUmogSSRWf8XNwG6x9R29OrmzNQhC9fCWrQcsBCWazmDCLLuHd0IfbNwYdssdUbyboTHIRRA2wwvZqKvQhVbqFDJfQZY7XLbFqUXpmBexOqoXNjkh20TB28MD70SUWFrxT5rRlaOdOZruBdPX2KQkJQuSuskCEPgE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=altlinux.org; spf=pass smtp.mailfrom=basealt.ru; arc=none smtp.client-ip=193.43.8.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=altlinux.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=basealt.ru Received: from localhost (broadband-46-242-4-129.ip.moscow.rt.ru [46.242.4.129]) (Authenticated sender: gremlin) by air.basealt.ru (Postfix) with ESMTPSA id 1136623372; Wed, 16 Apr 2025 14:54:17 +0300 (MSK) Date: Wed, 16 Apr 2025 14:54:16 +0300 From: "Alexey V. Vissarionov" To: Jon Hunter Cc: "Alexey V. Vissarionov" , Greg Kroah-Hartman , Thierry Reding , Uwe Kleine-Knig , Nagarjuna Kristam , linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org, lvc-project@linuxtesting.org Subject: Re: [PATCH v1] usb: tegra-xudc: check ep and ep->desc before deref Message-ID: <20250416115416.GC27292@altlinux.org> References: <20250415174204.GB6814@altlinux.org> <79265b11-c23a-4e4e-b7c3-6cf5b89b9977@nvidia.com> <20250416095555.GB27292@altlinux.org> <6e0b8bb7-c9c4-4625-bad0-552dcad89ea0@nvidia.com> Precedence: bulk X-Mailing-List: linux-tegra@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6e0b8bb7-c9c4-4625-bad0-552dcad89ea0@nvidia.com> Good ${greeting_time}! On 2025-04-16 11:20:10 +0100, Jon Hunter wrote: >> + /* trb_phys_to_virt() dereferences ep; check it here */ >> + if (!ep) >> + { > Please make sure you run 'checkpatch.pl' as I am sure if will > flag that the above should be ... > if (!ep) { ACK. >> + dev_err(xudc->dev, "Unbelievable: ep is NULL\n"); > I quite like the 'Unbelievable' but 'unexpected NULL pointer > for ep' is also fine. ACK. >> + /* tegra_xudc_req_done() dereferences ep->desc; check it >> here */ >> + if (!ep->desc) > I am not sure about the error message here, because the existing > code just skips this. So it is not clear if this can happen and > could be expected. Now ep->desc is checked immediately after tegra_xudc_req_done(), where it is dereferenced, so it was somehow expected. My suggestion is just to check this expection earlier. Next version of the patch follows. -- Alexey V. Vissarionov gremlin ðòé altlinux ôþë org; +vii-cmiii-ccxxix-lxxix-xlii GPG: 0D92F19E1C0DC36E27F61A29CD17E2B43D879005 @ hkp://keys.gnupg.net