From a666b6ffbc9b6705a3ced704f52c3fe9ea8bf959 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= Date: Mon, 29 Sep 2014 15:10:51 +0200 Subject: [PATCH] dell-wmi: Fix access out of memory MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Without this patch, dell-wmi is trying to access elements of dynamically allocated array without checking the array size. This can lead to memory corruption or a kernel panic. This patch adds the missing checks for array size. Signed-off-by: Pali Rohár Signed-off-by: Darren Hart --- drivers/platform/x86/dell-wmi.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c index 390e8e33d5e3..25721bf20092 100644 --- a/drivers/platform/x86/dell-wmi.c +++ b/drivers/platform/x86/dell-wmi.c @@ -163,18 +163,24 @@ static void dell_wmi_notify(u32 value, void *context) const struct key_entry *key; int reported_key; u16 *buffer_entry = (u16 *)obj->buffer.pointer; + int buffer_size = obj->buffer.length/2; - if (dell_new_hk_type && (buffer_entry[1] != 0x10)) { + if (buffer_size >= 2 && dell_new_hk_type && buffer_entry[1] != 0x10) { pr_info("Received unknown WMI event (0x%x)\n", buffer_entry[1]); kfree(obj); return; } - if (dell_new_hk_type || buffer_entry[1] == 0x0) + if (buffer_size >= 3 && (dell_new_hk_type || buffer_entry[1] == 0x0)) reported_key = (int)buffer_entry[2]; - else + else if (buffer_size >= 2) reported_key = (int)buffer_entry[1] & 0xffff; + else { + pr_info("Received unknown WMI event\n"); + kfree(obj); + return; + } key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev, reported_key);