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 3233E36CE03; Tue, 16 Dec 2025 12:17:57 +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=1765887477; cv=none; b=GORwi5kSec4cksVoi4J41Ui4Ln3ex/BvjHlbxJXYgKh+Q7dgarK0naWi8abLHyHcNcpTPn1H2NbD81IbT0ELOMRCQ+g85D1a80WWXQjijV4ExDJUVbT+H4x1xgIW7OQR4g+Fxg5goa9HGidZ9bqt/N8rMkFqCaTGQIT5HXKbMxI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765887477; c=relaxed/simple; bh=U8G3rveA/QpVMuECVKc3o6nVFDRrkVpkvN5EKCwoH+w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Eh2HwkIz1TDrWQdzz75geeW1eQT2z+rZBVyKJ3br3RZ+rAo6CYcUYn46c/H7klUPrKyU3F3J8Ly4Zdl8qjSykkTN/ZRlnSembMMgYIPiItKT6ZQJxuV4YPj0WGOMgIUqKSOZ14S8bHopSP34eiDGWWBZLAI9eUwYbLZvaL4BaBc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rPHtB4bd; 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="rPHtB4bd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2B36C4CEF1; Tue, 16 Dec 2025 12:17:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1765887477; bh=U8G3rveA/QpVMuECVKc3o6nVFDRrkVpkvN5EKCwoH+w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rPHtB4bdHVe+M53A+APU6K4u1PvsFAD3LlHctajl9RZwv8p6VR/H708ocUcSgUE0x yUZ2g50sG40v2dDb7AeaUH6Xd+Ah/HGF+BOxbdf1jzSZbNWG83JHtlJwOj6DMNn8Gk GDsqoJkQfKkeTJypejglOIzCn1qWjNGWr5S5XrM4= 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 6.18 209/614] coresight: ETR: Fix ETR buffer use-after-free issue Date: Tue, 16 Dec 2025 12:09:36 +0100 Message-ID: <20251216111408.947237575@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251216111401.280873349@linuxfoundation.org> References: <20251216111401.280873349@linuxfoundation.org> User-Agent: quilt/0.69 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 6.18-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 b07fcdb3fe1a8..800be06598c1b 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1250,6 +1250,13 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) * with the lock released. */ raw_spin_lock_irqsave(&drvdata->spinlock, flags); + + /* + * If the ETR is already enabled, continue with the existing buffer. + */ + if (coresight_get_mode(csdev) == CS_MODE_SYSFS) + goto out; + sysfs_buf = READ_ONCE(drvdata->sysfs_buf); if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) { raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); -- 2.51.0