[PATCH] PCI/sysfs: Fix double free in error path

From: Sascha Hauer
Date: Fri Oct 07 2022 - 02:56:40 EST


When pci_create_attr() fails then 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 we have to set the failed entry
to NULL in pci_create_attr() when freeing it.

Fixes: b562ec8f74e4 ("PCI: Don't leak memory if sysfs_create_bin_file() fails")
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
drivers/pci/pci-sysfs.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index fc804e08e3cb5..a07381d46ddae 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1196,8 +1196,13 @@ 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) {
+ if (write_combine)
+ pdev->res_attr_wc[num] = NULL;
+ else
+ pdev->res_attr[num] = NULL;
kfree(res_attr);
+ }

return retval;
}
--
2.30.2