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 9BF613DBD5E; Sat, 12 Sep 2026 10:12:51 +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=1789207972; cv=none; b=plrq2ANTttsIH09vSZzCopJYfVYLBskJbbuBNsZ7wM3StQMN/BCrniwpzOhZJ54aDEZ/dORQQTXjyjFVHZ2DXdYj/pzKYoZzoYHdPKKam+rC4m4ttSaJFu6j8fgYUpOcBJETuaLewwOAm4qk0qxYPi1mphmZiotp4x2Hr39/K68= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789207972; c=relaxed/simple; bh=FxGOaXNuuLsYkD2LDRTlrNXp3Cinvj1kPwQIpoGuH54=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YYdN0OhUSO3q1lR9/aKfBdvouaejinotvkUftbVWwU2MoRambkaQyL41ICHd+bQ4VUrSd12JM8R3jyAJZzO+kUEBjwmgc7XMREZewxvCNbnZ7yVy8fQbiRBAd+S4OzUdOieVJTMFOj6hi8tai+NtB+ezLyHnDR+/yVIp/xWIVic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1kSqW2aa; 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="1kSqW2aa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 389CF1F000FF; Sat, 12 Sep 2026 10:12:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789207971; bh=YIvaBKN//QTg0gwJvCN7AQcQ3Nfow6Xvbxpftb+bJSA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1kSqW2aa7s6dZcLW6qj5OPwpWVq9LKx6VXieEfCCiRiI6LebBR6KljQ07/LQ/W+1h 9HEBqQK50Pw7VYK+PqGAMcZZak5GeLoPRPpVVLdufmnNdrby3Fwa/3+uSwjdthbOyY WrmN2tGyUXbbapc5dZS/Q1af/bOKLy7F8+28diOE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li RongQing , Ankit Soni , Will Deacon , Sasha Levin Subject: [PATCH 6.18 0523/1518] iommu/amd: Fix undefined behavior in devid_write debugfs function Date: Sat, 12 Sep 2026 08:44:52 +0200 Message-ID: <20260912065635.277280543@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li RongQing [ Upstream commit 843e149989665f8309ad2efe6048dc76591e1f94 ] When for_each_pci_segment() loop completes without finding a matching segment, the pci_seg pointer is not NULL but points to an invalid memory location (the list head). Accessing pci_seg->id after the loop causes undefined behavior. Fix this by handling the successful case inside the loop and returning -EINVAL after the loop if no matching segment is found. Fixes: 2e98940f123d9 ("iommu/amd: Add support for device id user input") Signed-off-by: Li RongQing Reviewed-by: Ankit Soni Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/amd/debugfs.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/amd/debugfs.c b/drivers/iommu/amd/debugfs.c index 3909a1fb218e9..f7bb551d285f6 100644 --- a/drivers/iommu/amd/debugfs.c +++ b/drivers/iommu/amd/debugfs.c @@ -176,19 +176,13 @@ static ssize_t devid_write(struct file *filp, const char __user *ubuf, kfree(srcid_ptr); return -ENODEV; } - break; - } - - if (pci_seg->id != seg) { + sbdf = PCI_SEG_DEVID_TO_SBDF(seg, devid); kfree(srcid_ptr); - return -EINVAL; + return cnt; } - sbdf = PCI_SEG_DEVID_TO_SBDF(seg, devid); - kfree(srcid_ptr); - - return cnt; + return -EINVAL; } static int devid_show(struct seq_file *m, void *unused) -- 2.53.0