From 67fe63b0715ccfaefa0af8a6e705c5470ee5cada Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 7 Jan 2010 12:58:51 -0700 Subject: [PATCH] agp/hp: fixup hp agp after ACPI changes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 15b8dd53f5ffa changed the string in info->hardware_id from a static array to a pointer and added a length field. But instead of changing "sizeof(array)" to "length", we changed it to "sizeof(length)" (== 4), which corrupts the string we're trying to null-terminate. We no longer even need to null-terminate the string, but we *do* need to check whether we found a HID. If there's no HID, we used to have an empty array, but now we have a null pointer. The combination of these defects causes this oops: Unable to handle kernel NULL pointer dereference (address 0000000000000003) modprobe[895]: Oops 8804682956800 [1] ip is at zx1_gart_probe+0xd0/0xcc0 [hp_agp] http://marc.info/?l=linux-ia64&m=126264484923647&w=2 Signed-off-by: Bjorn Helgaas Reported-by: Émeric Maschino Signed-off-by: Dave Airlie --- drivers/char/agp/hp-agp.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/char/agp/hp-agp.c b/drivers/char/agp/hp-agp.c index 9047b271465..dc8a6f70483 100644 --- a/drivers/char/agp/hp-agp.c +++ b/drivers/char/agp/hp-agp.c @@ -488,9 +488,8 @@ zx1_gart_probe (acpi_handle obj, u32 depth, void *context, void **ret) handle = obj; do { status = acpi_get_object_info(handle, &info); - if (ACPI_SUCCESS(status)) { + if (ACPI_SUCCESS(status) && (info->valid & ACPI_VALID_HID)) { /* TBD check _CID also */ - info->hardware_id.string[sizeof(info->hardware_id.length)-1] = '\0'; match = (strcmp(info->hardware_id.string, "HWP0001") == 0); kfree(info); if (match) { -- 2.11.4.GIT