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 3B53826B099; Thu, 13 Feb 2025 15:10:44 +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=1739459444; cv=none; b=VvA8k2qbuvr4mhq86xAJNxKGrhUjCdbdHS7Y5tElewniCSfxklcMTCrHvg8nUajSLhY5WDpkPbqIG0sS6jrh+CfXT43Cm73icKn5O587q+S6JAn+r4NPl9L1p1UAQ2glXDHi1Xq6h6Na0WttRb0a42Nt6cMnKpCmy0SNyeZCVBI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739459444; c=relaxed/simple; bh=7XW2O377xc1AvbXH60iUNCbjcyvB3pg+4jE00J5ameI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SQFTrmsNWVcyzh603vWupEJiBB+YepJ8bvcAMLhpZVhcsvGJWXf/UNYSf3iQnMPuQ7XOl5IE1HoBnW6lOh2aJG5E1VLZWqCkf7oyyNVmpC56B8rRsAtGK/g3aseyORnPXYHUq6NxB8SiyHsdubC8N548O+vdp7yKOJBAb0vQTNQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=C/DRXtmL; 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="C/DRXtmL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DD94C4CEE4; Thu, 13 Feb 2025 15:10:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739459444; bh=7XW2O377xc1AvbXH60iUNCbjcyvB3pg+4jE00J5ameI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C/DRXtmLArHlO8FL7ymiLIpH/oIofBjMLHFoMEbi4PX1Fur/F4kQXFK0kNJlB02rB y/w8ej1gbXXebhJC2ojzUFPuA1r+4rbbWI5FxYODrb/611HVe2gWOWJ1n7tspSryE1 qDTRvmA1Al5vjmL+BzX5aQIWSIBfVsxi3P/bDXUw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Krzysztof Kozlowski , Bjorn Andersson Subject: [PATCH 6.13 266/443] firmware: qcom: scm: Fix missing read barrier in qcom_scm_get_tzmem_pool() Date: Thu, 13 Feb 2025 15:27:11 +0100 Message-ID: <20250213142450.880117954@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250213142440.609878115@linuxfoundation.org> References: <20250213142440.609878115@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Krzysztof Kozlowski commit b628510397b5cafa1f5d3e848a28affd1c635302 upstream. Commit 2e4955167ec5 ("firmware: qcom: scm: Fix __scm and waitq completion variable initialization") introduced a write barrier in probe function to store global '__scm' variable. We all known barriers are paired (see memory-barriers.txt: "Note that write barriers should normally be paired with read or address-dependency barriers"), therefore accessing it from concurrent contexts requires read barrier. Previous commit added such barrier in qcom_scm_is_available(), so let's use that directly. Lack of this read barrier can result in fetching stale '__scm' variable value, NULL, and dereferencing it. Note that barrier in qcom_scm_is_available() satisfies here the control dependency. Fixes: ca61d6836e6f ("firmware: qcom: scm: fix a NULL-pointer dereference") Fixes: 449d0d84bcd8 ("firmware: qcom: scm: smc: switch to using the SCM allocator") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20241209-qcom-scm-missing-barriers-and-all-sort-of-srap-v2-2-9061013c8d92@linaro.org Signed-off-by: Bjorn Andersson Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/qcom/qcom_scm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/firmware/qcom/qcom_scm.c +++ b/drivers/firmware/qcom/qcom_scm.c @@ -217,7 +217,10 @@ static DEFINE_SPINLOCK(scm_query_lock); struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void) { - return __scm ? __scm->mempool : NULL; + if (!qcom_scm_is_available()) + return NULL; + + return __scm->mempool; } static enum qcom_scm_convention __get_convention(void)