From: Thadeu Lima de Souza Cascardo Date: Sun, 28 Nov 2010 21:46:50 +0000 (-0200) Subject: wmi: use memcmp instead of strncmp to compare GUIDs X-Git-Tag: v2.6.33.8~293 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=971a8db01d3de4f15e6aff74012b2e68387700e3;p=thirdparty%2Fkernel%2Fstable.git wmi: use memcmp instead of strncmp to compare GUIDs commit 8b14d7b22c61f17ccb869e0047d9df6dd9f50a9f upstream. While looking for the duplicates in /sys/class/wmi/, I couldn't find them. The code that looks for duplicates uses strncmp in a binary GUID, which may contain zero bytes. The right function is memcmp, which is also used in another section of wmi code. It was finding 49142400-C6A3-40FA-BADB-8A2652834100 as a duplicate of 39142400-C6A3-40FA-BADB-8A2652834100. Since the first byte is the fourth printed, they were found as equal by strncmp. Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Matthew Garrett Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index b104302fea0a1..a82f18ec8e4c9 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -724,7 +724,7 @@ static bool guid_already_parsed(const char *guid_string) wblock = list_entry(p, struct wmi_block, list); gblock = &wblock->gblock; - if (strncmp(gblock->guid, guid_string, 16) == 0) + if (memcmp(gblock->guid, guid_string, 16) == 0) return true; } return false;