[PATCH] PCI: fix memory leak in reset_method_store()

From: Todd Kjos
Date: Tue Oct 01 2024 - 19:13:15 EST


In reset_method_store(), a string is allocated via kstrndup()
and assigned to the local "options". options is then used
in with strsep() to find spaces:

while ((name = strsep(&options, " ")) != NULL) {

If there are no remaining spaces, then options is set to NULL
by strsep(), so the subsequent kfree(options) doesn't free the
memory allocated via kstrndup().

Fix by using a separate tmp_options to iterate with
strsep() so options is preserved.

Fixes: d88f521da3ef ("PCI: Allow userspace to query and set device reset mechanism")
Signed-off-by: Todd Kjos <tkjos@xxxxxxxxxx>
---
drivers/pci/pci.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7d85c04fbba2..0e6562ff3dcf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5244,7 +5244,7 @@ static ssize_t reset_method_store(struct device *dev,
const char *buf, size_t count)
{
struct pci_dev *pdev = to_pci_dev(dev);
- char *options, *name;
+ char *options, *tmp_options, *name;
int m, n;
u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };

@@ -5264,7 +5264,8 @@ static ssize_t reset_method_store(struct device *dev,
return -ENOMEM;

n = 0;
- while ((name = strsep(&options, " ")) != NULL) {
+ tmp_options = options;
+ while ((name = strsep(&tmp_options, " ")) != NULL) {
if (sysfs_streq(name, ""))
continue;

--
2.46.1.824.gd892dcdcdd-goog