From aa382ffa705bea9931ec92b6f3c70e1fdb372195 Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Tue, 8 Nov 2022 17:05:59 -0600
Subject: [PATCH] PCI/sysfs: Fix double free in error path
Git-commit: aa382ffa705bea9931ec92b6f3c70e1fdb372195
Patch-mainline: v6.2-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
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/pci/pci-sysfs.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 0a2eeb82cebd..ba38fc47d35e 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1175,11 +1175,9 @@ static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
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;
@@ -1197,10 +1195,17 @@ static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
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;
}
/**
--
2.35.3