From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Tue, 8 Nov 2022 17:05:59 -0600
Subject: PCI/sysfs: Fix double free in error path
Git-commit: aa382ffa705bea9931ec92b6f3c70e1fdb372195
Patch-mainline: 6.2-rc1
References: git-fixes

When pci_create_attr() fails, pci_remove_resource_files() is called which
will iterate over the res_attr[_wc] arrays and frees every non NULL entry.
To avoid a double free here set the array entry only after it's clear we
successfully initialized it.

Fixes: b562ec8f74e4 ("PCI: Don't leak memory if sysfs_create_bin_file() fails")
Link: https://lore.kernel.org/r/20221007070735.GX986@pengutronix.de/
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/pci/pci-sysfs.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1291,11 +1291,9 @@ static int pci_create_attr(struct pci_de
 
 	sysfs_bin_attr_init(res_attr);
 	if (write_combine) {
-		pdev->res_attr_wc[num] = res_attr;
 		sprintf(res_attr_name, "resource%d_wc", num);
 		res_attr->mmap = pci_mmap_resource_wc;
 	} else {
-		pdev->res_attr[num] = res_attr;
 		sprintf(res_attr_name, "resource%d", num);
 		if (pci_resource_flags(pdev, num) & IORESOURCE_IO) {
 			res_attr->read = pci_read_resource_io;
@@ -1311,10 +1309,17 @@ static int pci_create_attr(struct pci_de
 	res_attr->size = pci_resource_len(pdev, num);
 	res_attr->private = (void *)(unsigned long)num;
 	retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
-	if (retval)
+	if (retval) {
 		kfree(res_attr);
+		return retval;
+	}
+
+	if (write_combine)
+		pdev->res_attr_wc[num] = res_attr;
+	else
+		pdev->res_attr[num] = res_attr;
 
-	return retval;
+	return 0;
 }
 
 /**