linux-kernel - Re: [PATCH v2] PCI/ACPI: Fix double free bug in pci_acpi_scan

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <f04d01a7-28f5-41ea-85f6-ba0e67c80428@suswa.mountain>
Date: Wed, 18 Jun 2025 19:02:27 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Zhe Qiao <qiaozhe@...as.ac.cn>
Cc: rafael@...nel.org, bhelgaas@...gle.com, lenb@...nel.org,
	kwilczynski@...nel.org, sashal@...nel.org,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	linux-acpi@...r.kernel.org
Subject: Re: [PATCH v2] PCI/ACPI: Fix double free bug in pci_acpi_scan_root()
 function

Wait, what?  We can't just delete pci_acpi_generic_release_info().
What's going to free all those things on the success path?  I
don't understand.

I had suggested you do something like this:

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 74ade4160314..ff5799b696d6 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -1012,20 +1012,20 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 		 root->segment, busnum);
 
 	if (ops->init_info && ops->init_info(info))
-		goto out_release_info;
+		return NULL;
 	if (ops->prepare_resources)
 		ret = ops->prepare_resources(info);
 	else
 		ret = acpi_pci_probe_root_resources(info);
 	if (ret < 0)
-		goto out_release_info;
+		goto cleanup_init_info;
 
 	pci_acpi_root_add_resources(info);
 	pci_add_resource(&info->resources, &root->secondary);
 	bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
 				  sysdata, &info->resources);
 	if (!bus)
-		goto out_release_info;
+		goto cleanup_acpi_pci_probe_root_resources;
 
 	host_bridge = to_pci_host_bridge(bus->bridge);
 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
@@ -1053,8 +1053,10 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 		dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
 	return bus;
 
+cleanup_acpi_pci_probe_root_resources:
+	free_something_with_probe();
 out_release_info:
-	__acpi_pci_root_release_info(info);
+	free_something_info();
 	return NULL;
 }
 

But you'd need to replace the dummy code with actual code and
change the callers etc.  And I haven't looked at the actual
code to verify it's a good idea.

regards,
dan carpenter