Commit 27d6627f authored by Todd Kjos's avatar Todd Kjos Committed by Zeng Heng
Browse files

PCI: Fix reset_method_store() memory leak 

stable inclusion
from stable-v6.6.64
commit 8e098baf6bc3f3a6aefc383509aba07e202f7ee0
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEGF6
CVE: CVE-2024-56745

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8e098baf6bc3f3a6aefc383509aba07e202f7ee0

--------------------------------

[ Upstream commit 2985b1844f3f3447f2d938eff1ef6762592065a5 ]

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.

Link: https://lore.kernel.org/r/20241001231147.3583649-1-tkjos@google.com


Fixes: d88f521d ("PCI: Allow userspace to query and set device reset mechanism")
Signed-off-by: default avatarTodd Kjos <tkjos@google.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
parent 99141177

drivers/pci/pci.c

+3 −2
Original line number Diff line number Diff line
@@ -5463,7 +5463,7 @@ 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 };
@@ -5483,7 +5483,8 @@ 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;