From: Todd Kjos tkjos@google.com

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=...

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

[ 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: d88f521da3ef ("PCI: Allow userspace to query and set device reset mechanism") Signed-off-by: Todd Kjos tkjos@google.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zeng Heng zengheng4@huawei.com --- 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 cd7903702f57..e02bf0c1f35e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -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;