From ad90e82a0b7efca7aa7a6da2ff319eaba7afdc0e Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] PCI: Fix reset_method_store() memory leak BugLink: https://bugs.launchpad.net/bugs/2101915 [ 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 Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin CVE-2024-56745 Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- 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 7a448233e544..be2eb5c28bfe 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5452,7 +5452,7 @@ 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 }; @@ -5472,7 +5472,8 @@ 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;