From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C10243C13FD; Sat, 17 Oct 2026 17:31:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792258278; cv=none; b=Uwb0oowrRtVRPar6DAHfsDSRh+SKWETn27P2hI8vADVqQZhz3x1HqGDliyAVvnhMnT4XbjYncEnRfA6np18HjWPreq7LsooOJo2qglrDOvmlkE+6YdhECyuz3YH7YBVWjfeTZ+MdatfhNll7E9z0oWCEPF3QR5wWrowlHvu9tMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792258278; c=relaxed/simple; bh=aqebw9zij9W00tXEXhYNBqS6SgJVvA+NuqZU1KIuZOs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CCSfhhPeKCNvcEbCpptEsGJiyPFPlUl6Jd9A4c/Q/cNf+QAYfmww++0scaGJY0eNDZLTU1rUv+D9AHVbtFBIuIwEwHihfjew5rsaCqzbWkV4zR2bUwr/805dRKnUWcedXGhgkA0gvr7ovOGZDMSOdqztUL79h9eW+DaivJKVS3Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=r+mc24bm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="r+mc24bm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F2B41F000C4; Sat, 17 Oct 2026 17:31:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792258277; bh=eCYfevL58UFUHQqxH45XXXcTzA0KXa471g3fzis4P6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=r+mc24bmbawwi49ob7kBT+tbaREJYbuaxFwjKGOFXy/3tnaOBuAdMqyTdTMNhP0m1 XHOz82AO4qiSftcTodLjnDXGI2DrQL6qeX4P2w+1S6RTvf4/DpTVE9+/HN6J8Eyy6n o24cYvV6Y/Z36NMQblgmAX2tiHgU9XuOOYISAaRI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiaoqi Zhuang , Suzuki K Poulose , Leo Yan , Sasha Levin Subject: [PATCH 6.6 0830/1674] coresight: ETR: Fix ETR buffer use-after-free issue Date: Sat, 17 Oct 2026 17:51:42 +0200 Message-ID: <20261017160452.429356195@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiaoqi Zhuang [ Upstream commit 35501ac3c7d40a7bb9568c2f89d6b56beaf9bed3 ] When ETR is enabled as CS_MODE_SYSFS, if the buffer size is changed and enabled again, currently sysfs_buf will point to the newly allocated memory(buf_new) and free the old memory(buf_old). But the etr_buf that is being used by the ETR remains pointed to buf_old, not updated to buf_new. In this case, it will result in a memory use-after-free issue. Fix this by checking ETR's mode before updating and releasing buf_old, if the mode is CS_MODE_SYSFS, then skip updating and releasing it. Fixes: bd2767ec3df2 ("coresight: Fix run time warnings while reusing ETR buffer") Signed-off-by: Xiaoqi Zhuang Signed-off-by: Suzuki K Poulose Tested-by: Leo Yan Link: https://lore.kernel.org/r/20251021-fix_etr_issue-v3-1-99a2d066fee2@oss.qualcomm.com Signed-off-by: Sasha Levin --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index f3312fbcdc0f8..e9b8a396e4ba8 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1156,6 +1156,13 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) * with the lock released. */ spin_lock_irqsave(&drvdata->spinlock, flags); + + /* + * If the ETR is already enabled, continue with the existing buffer. + */ + if (drvdata->mode == CS_MODE_SYSFS) + goto out; + sysfs_buf = READ_ONCE(drvdata->sysfs_buf); if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) { spin_unlock_irqrestore(&drvdata->spinlock, flags); -- 2.53.0