summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAnirudh Rayabharam <mail@anirudhrb.com>2021-04-25 23:03:53 +0530
committerJiri Kosina <jkosina@suse.cz>2021-05-05 15:52:34 +0200
commit6be388f4a35d2ce5ef7dbf635a8964a5da7f799f (patch)
tree6e4a7f2bd3471fa91be4a74f4eeafe49d77598eb
parent48e33befe61a7d407753c53d1a06fc8d6b5dab80 (diff)
HID: usbhid: fix info leak in hid_submit_ctrl
In hid_submit_ctrl(), the way of calculating the report length doesn't take into account that report->size can be zero. When running the syzkaller reproducer, a report of size 0 causes hid_submit_ctrl) to calculate transfer_buffer_length as 16384. When this urb is passed to the usb core layer, KMSAN reports an info leak of 16384 bytes. To fix this, first modify hid_report_len() to account for the zero report size case by using DIV_ROUND_UP for the division. Then, call it from hid_submit_ctrl(). Reported-by: syzbot+7c2bb71996f95a82524c@syzkaller.appspotmail.com Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r--drivers/hid/usbhid/hid-core.c2
-rw-r--r--include/linux/hid.h3
2 files changed, 2 insertions, 3 deletions
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 86257ce6d619..4e9077363c96 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -374,7 +374,7 @@ static int hid_submit_ctrl(struct hid_device *hid)
raw_report = usbhid->ctrl[usbhid->ctrltail].raw_report;
dir = usbhid->ctrl[usbhid->ctrltail].dir;
- len = ((report->size - 1) >> 3) + 1 + (report->id > 0);
+ len = hid_report_len(report);
if (dir == USB_DIR_OUT) {
usbhid->urbctrl->pipe = usb_sndctrlpipe(hid_to_usb_dev(hid), 0);
usbhid->urbctrl->transfer_buffer_length = len;
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 271021e20a3f..10e922cee4eb 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -1167,8 +1167,7 @@ static inline void hid_hw_wait(struct hid_device *hdev)
*/
static inline u32 hid_report_len(struct hid_report *report)
{
- /* equivalent to DIV_ROUND_UP(report->size, 8) + !!(report->id > 0) */
- return ((report->size - 1) >> 3) + 1 + (report->id > 0);
+ return DIV_ROUND_UP(report->size, 8) + (report->id > 0);
}
int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,