f11274396a
uref->usage_index can be indirectly controlled by userspace, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This field is used as an array index by the hiddev_ioctl_usage() function, when 'cmd' is either HIDIOCGCOLLECTIONINDEX, HIDIOCGUSAGES or HIDIOCSUSAGES. For cmd == HIDIOCGCOLLECTIONINDEX case, uref->usage_index is compared to field->maxusage and then used as an index to dereference field->usage array. The same thing happens to the cmd == HIDIOC{G,S}USAGES cases, where uref->usage_index is checked against an array maximum value and then it is used as an index in an array. This is a summary of the HIDIOCGCOLLECTIONINDEX case, which matches the traditional Spectre V1 first load: copy_from_user(uref, user_arg, sizeof(*uref)) if (uref->usage_index >= field->maxusage) goto inval; i = field->usage[uref->usage_index].collection_index; return i; This patch fixes this by sanitizing field uref->usage_index before using it to index field->usage (HIDIOCGCOLLECTIONINDEX) or field->value in HIDIOC{G,S}USAGES arrays, thus, avoiding speculation in the first load. Cc: <stable@vger.kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> -- v2: Contemplate cmd == HIDIOC{G,S}USAGES case Signed-off-by: Jiri Kosina <jkosina@suse.cz> |
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.. | ||
hid-core.c | ||
hid-pidff.c | ||
hiddev.c | ||
Kconfig | ||
Makefile | ||
usbhid.h | ||
usbkbd.c | ||
usbmouse.c |