projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| c55ac56b GKH |
1 | From 4f65245f2d178b9cba48350620d76faa4a098841 Mon Sep 17 00:00:00 2001 |
| 2 | From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> | |
| 3 | Date: Fri, 29 Jun 2018 17:08:44 -0500 | |
| 4 | Subject: HID: hiddev: fix potential Spectre v1 | |
| 5 | ||
| 6 | From: Gustavo A. R. Silva <gustavo@embeddedor.com> | |
| 7 | ||
| 8 | commit 4f65245f2d178b9cba48350620d76faa4a098841 upstream. | |
| 9 | ||
| 10 | uref->field_index, uref->usage_index, finfo.field_index and cinfo.index can be | |
| 11 | indirectly controlled by user-space, hence leading to a potential exploitation | |
| 12 | of the Spectre variant 1 vulnerability. | |
| 13 | ||
| 14 | This issue was detected with the help of Smatch: | |
| 15 | ||
| 16 | drivers/hid/usbhid/hiddev.c:473 hiddev_ioctl_usage() warn: potential spectre issue 'report->field' (local cap) | |
| 17 | drivers/hid/usbhid/hiddev.c:477 hiddev_ioctl_usage() warn: potential spectre issue 'field->usage' (local cap) | |
| 18 | drivers/hid/usbhid/hiddev.c:757 hiddev_ioctl() warn: potential spectre issue 'report->field' (local cap) | |
| 19 | drivers/hid/usbhid/hiddev.c:801 hiddev_ioctl() warn: potential spectre issue 'hid->collection' (local cap) | |
| 20 | ||
| 21 | Fix this by sanitizing such structure fields before using them to index | |
| 22 | report->field, field->usage and hid->collection | |
| 23 | ||
| 24 | Notice that given that speculation windows are large, the policy is | |
| 25 | to kill the speculation on the first load and not worry if it can be | |
| 26 | completed with a dependent load/store [1]. | |
| 27 | ||
| 28 | [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 | |
| 29 | ||
| 30 | Cc: stable@vger.kernel.org | |
| 31 | Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> | |
| 32 | Signed-off-by: Jiri Kosina <jkosina@suse.cz> | |
| 33 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 34 | ||
| 35 | --- | |
| 36 | drivers/hid/usbhid/hiddev.c | 11 +++++++++++ | |
| 37 | 1 file changed, 11 insertions(+) | |
| 38 | ||
| 39 | --- a/drivers/hid/usbhid/hiddev.c | |
| 40 | +++ b/drivers/hid/usbhid/hiddev.c | |
| 41 | @@ -35,6 +35,7 @@ | |
| 42 | #include <linux/hiddev.h> | |
| 43 | #include <linux/compat.h> | |
| 44 | #include <linux/vmalloc.h> | |
| 45 | +#include <linux/nospec.h> | |
| 46 | #include "usbhid.h" | |
| 47 | ||
| 48 | #ifdef CONFIG_USB_DYNAMIC_MINORS | |
| 49 | @@ -478,10 +479,14 @@ static noinline int hiddev_ioctl_usage(s | |
| 50 | ||
| 51 | if (uref->field_index >= report->maxfield) | |
| 52 | goto inval; | |
| 53 | + uref->field_index = array_index_nospec(uref->field_index, | |
| 54 | + report->maxfield); | |
| 55 | ||
| 56 | field = report->field[uref->field_index]; | |
| 57 | if (uref->usage_index >= field->maxusage) | |
| 58 | goto inval; | |
| 59 | + uref->usage_index = array_index_nospec(uref->usage_index, | |
| 60 | + field->maxusage); | |
| 61 | ||
| 62 | uref->usage_code = field->usage[uref->usage_index].hid; | |
| 63 | ||
| 64 | @@ -508,6 +513,8 @@ static noinline int hiddev_ioctl_usage(s | |
| 65 | ||
| 66 | if (uref->field_index >= report->maxfield) | |
| 67 | goto inval; | |
| 68 | + uref->field_index = array_index_nospec(uref->field_index, | |
| 69 | + report->maxfield); | |
| 70 | ||
| 71 | field = report->field[uref->field_index]; | |
| 72 | ||
| 73 | @@ -761,6 +768,8 @@ static long hiddev_ioctl(struct file *fi | |
| 74 | ||
| 75 | if (finfo.field_index >= report->maxfield) | |
| 76 | break; | |
| 77 | + finfo.field_index = array_index_nospec(finfo.field_index, | |
| 78 | + report->maxfield); | |
| 79 | ||
| 80 | field = report->field[finfo.field_index]; | |
| 81 | memset(&finfo, 0, sizeof(finfo)); | |
| 82 | @@ -801,6 +810,8 @@ static long hiddev_ioctl(struct file *fi | |
| 83 | ||
| 84 | if (cinfo.index >= hid->maxcollection) | |
| 85 | break; | |
| 86 | + cinfo.index = array_index_nospec(cinfo.index, | |
| 87 | + hid->maxcollection); | |
| 88 | ||
| 89 | cinfo.type = hid->collection[cinfo.index].type; | |
| 90 | cinfo.usage = hid->collection[cinfo.index].usage; |