diff options
| author | Anirudh Rayabharam <mail@anirudhrb.com> | 2021-04-25 23:03:53 +0530 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2021-05-05 15:52:34 +0200 |
| commit | 6be388f4a35d2ce5ef7dbf635a8964a5da7f799f (patch) | |
| tree | 6e4a7f2bd3471fa91be4a74f4eeafe49d77598eb | |
| parent | 48e33befe61a7d407753c53d1a06fc8d6b5dab80 (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.c | 2 | ||||
| -rw-r--r-- | include/linux/hid.h | 3 |
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, |