diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-06-29 17:08:44 -0500 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2018-07-09 14:31:14 +0200 |
| commit | 4f65245f2d178b9cba48350620d76faa4a098841 (patch) | |
| tree | 640f4a6c360ea79716616a53003e689ec664f96c | |
| parent | ef6eaf27274c0351f7059163918f3795da13199c (diff) | |
HID: hiddev: fix potential Spectre v1
uref->field_index, uref->usage_index, finfo.field_index and cinfo.index can be
indirectly controlled by user-space, hence leading to a potential exploitation
of the Spectre variant 1 vulnerability.
This issue was detected with the help of Smatch:
drivers/hid/usbhid/hiddev.c:473 hiddev_ioctl_usage() warn: potential spectre issue 'report->field' (local cap)
drivers/hid/usbhid/hiddev.c:477 hiddev_ioctl_usage() warn: potential spectre issue 'field->usage' (local cap)
drivers/hid/usbhid/hiddev.c:757 hiddev_ioctl() warn: potential spectre issue 'report->field' (local cap)
drivers/hid/usbhid/hiddev.c:801 hiddev_ioctl() warn: potential spectre issue 'hid->collection' (local cap)
Fix this by sanitizing such structure fields before using them to index
report->field, field->usage and hid->collection
Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].
[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| -rw-r--r-- | drivers/hid/usbhid/hiddev.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index e3ce233f8bdc..23872d08308c 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -36,6 +36,7 @@ #include <linux/hiddev.h> #include <linux/compat.h> #include <linux/vmalloc.h> +#include <linux/nospec.h> #include "usbhid.h" #ifdef CONFIG_USB_DYNAMIC_MINORS @@ -469,10 +470,14 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, if (uref->field_index >= report->maxfield) goto inval; + uref->field_index = array_index_nospec(uref->field_index, + report->maxfield); field = report->field[uref->field_index]; if (uref->usage_index >= field->maxusage) goto inval; + uref->usage_index = array_index_nospec(uref->usage_index, + field->maxusage); uref->usage_code = field->usage[uref->usage_index].hid; @@ -499,6 +504,8 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, if (uref->field_index >= report->maxfield) goto inval; + uref->field_index = array_index_nospec(uref->field_index, + report->maxfield); field = report->field[uref->field_index]; @@ -753,6 +760,8 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (finfo.field_index >= report->maxfield) break; + finfo.field_index = array_index_nospec(finfo.field_index, + report->maxfield); field = report->field[finfo.field_index]; memset(&finfo, 0, sizeof(finfo)); @@ -797,6 +806,8 @@ static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (cinfo.index >= hid->maxcollection) break; + cinfo.index = array_index_nospec(cinfo.index, + hid->maxcollection); cinfo.type = hid->collection[cinfo.index].type; cinfo.usage = hid->collection[cinfo.index].usage; |