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 2525014B084; Fri, 6 Dec 2024 14:43:21 +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=1733496201; cv=none; b=HXgV2GtFCIkKECmn/mH+aWeTyOiDm/kA0Bwiny3wqLaUGZi+YcQWhss0U5fIluKjYe22OdOAk3BzkXftWuLt7pSh6p9vBHUBCzgOMmEA8FoKwb25VaFNamMrUMlZx4ztJ0x42gIZlxJq37bYZHaJG6k2I0eap4IN2hTIauOsSFE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733496201; c=relaxed/simple; bh=nlpaO/EM0+Cmt+aujYHUZGtf16ii7YIwVIA5+W+6hdo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T64Ohkl48MCj6Ie6tHM2qTY54JeISIM7SskPQWQx5NIQAq4ppEaDeHz2AeY+904pIzcAvdoQpm9FenDNHAQH53IMUgzU4us82hVHvmDm95SSAPq0N3RqyVkav5RPyTPn98fYLG1Qj0iF7A/xgMguH9j/WvIJXhzrwlgJqgEFk8s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NY/g2+gq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NY/g2+gq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 888C2C4CED1; Fri, 6 Dec 2024 14:43:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733496201; bh=nlpaO/EM0+Cmt+aujYHUZGtf16ii7YIwVIA5+W+6hdo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NY/g2+gqlCumLjAsbhfbguXumZ6YK30P3R/QYYF+hkbHHkpDA6YfpQ5e6ya9HmLnb hJzSmM3JEs/VLX98VQEEJ22eeVwsJ4U6Yd9cZqEg2qAAD/ah4zu455xgIh4z9VBjJ3 itnocWMasLOUbIFOgn0fZxPa9St+XCWvxijUPqCc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Prakash Gupta , Pratyush Brahma , Will Deacon Subject: [PATCH 6.12 049/146] iommu/arm-smmu: Defer probe of clients after smmu device bound Date: Fri, 6 Dec 2024 15:36:20 +0100 Message-ID: <20241206143529.552199607@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206143527.654980698@linuxfoundation.org> References: <20241206143527.654980698@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pratyush Brahma commit 229e6ee43d2a160a1592b83aad620d6027084aad upstream. Null pointer dereference occurs due to a race between smmu driver probe and client driver probe, when of_dma_configure() for client is called after the iommu_device_register() for smmu driver probe has executed but before the driver_bound() for smmu driver has been called. Following is how the race occurs: T1:Smmu device probe T2: Client device probe really_probe() arm_smmu_device_probe() iommu_device_register() really_probe() platform_dma_configure() of_dma_configure() of_dma_configure_id() of_iommu_configure() iommu_probe_device() iommu_init_device() arm_smmu_probe_device() arm_smmu_get_by_fwnode() driver_find_device_by_fwnode() driver_find_device() next_device() klist_next() /* null ptr assigned to smmu */ /* null ptr dereference while smmu->streamid_mask */ driver_bound() klist_add_tail() When this null smmu pointer is dereferenced later in arm_smmu_probe_device, the device crashes. Fix this by deferring the probe of the client device until the smmu device has bound to the arm smmu driver. Fixes: 021bb8420d44 ("iommu/arm-smmu: Wire up generic configuration support") Cc: stable@vger.kernel.org Co-developed-by: Prakash Gupta Signed-off-by: Prakash Gupta Signed-off-by: Pratyush Brahma Link: https://lore.kernel.org/r/20241004090428.2035-1-quic_pbrahma@quicinc.com [will: Add comment] Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1437,6 +1437,17 @@ static struct iommu_device *arm_smmu_pro goto out_free; } else { smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); + + /* + * Defer probe if the relevant SMMU instance hasn't finished + * probing yet. This is a fragile hack and we'd ideally + * avoid this race in the core code. Until that's ironed + * out, however, this is the most pragmatic option on the + * table. + */ + if (!smmu) + return ERR_PTR(dev_err_probe(dev, -EPROBE_DEFER, + "smmu dev has not bound yet\n")); } ret = -EINVAL;