HID: core: fix off-by-one memset in hid_report_raw_event()
authorJohan Korsnes <jkorsnes@cisco.com>
Fri, 17 Jan 2020 12:08:35 +0000 (13:08 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 11 Mar 2020 06:53:06 +0000 (07:53 +0100)
commite63e7efc68e1ace5bcb08d919809513bc2095f1b
tree8b4d37e8aac83848d006d4b883e61ee336ef725e
parente5d99f3c01f62cfed781ee07552bfdfffd716a2f
HID: core: fix off-by-one memset in hid_report_raw_event()

commit 5ebdffd25098898aff1249ae2f7dbfddd76d8f8f upstream.

In case a report is greater than HID_MAX_BUFFER_SIZE, it is truncated,
but the report-number byte is not correctly handled. This results in a
off-by-one in the following memset, causing a kernel Oops and ensuing
system crash.

Note: With commit 8ec321e96e05 ("HID: Fix slab-out-of-bounds read in
hid_field_extract") I no longer hit the kernel Oops as we instead fail
"controlled" at probe if there is a report too long in the HID
report-descriptor. hid_report_raw_event() is an exported symbol, so
presumabely we cannot always rely on this being the case.

Fixes: 966922f26c7f ("HID: fix a crash in hid_report_raw_event()
                     function.")
Signed-off-by: Johan Korsnes <jkorsnes@cisco.com>
Cc: Armando Visconti <armando.visconti@st.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hid/hid-core.c