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authorBjorn Helgaas <bjorn.helgaas@hp.com>2010-01-07 12:58:51 -0700
committerDave Airlie <airlied@redhat.com>2010-01-11 15:09:02 +1000
commit67fe63b0715ccfaefa0af8a6e705c5470ee5cada (patch)
tree0cc5d9be7755311b8b73806d976bffc9c1852bdd /drivers/char/agp
parent3f50b0222e4c6ac59a5c4819f8be0fa500970381 (diff)
downloadlinux-67fe63b0715ccfaefa0af8a6e705c5470ee5cada.tar.bz2
agp/hp: fixup hp agp after ACPI changes
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 <bjorn.helgaas@hp.com> Reported-by: Émeric Maschino <emeric.maschino@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/char/agp')
-rw-r--r--drivers/char/agp/hp-agp.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/char/agp/hp-agp.c b/drivers/char/agp/hp-agp.c
index 9047b2714653..dc8a6f70483b 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) {