Commit d63fd5ad authored Dec 05, 2020 by Will McVicker Committed by Gerrit - the friendly Code Review server Jun 10, 2021

HID: make arrays usage and value to be the same



The HID subsystem allows an "HID report field" to have a different
number of "values" and "usages" when it is allocated. When a field
struct is created, the size of the usage array is guaranteed to be at
least as large as the values array, but it may be larger. This leads to
a potential out-of-bounds write in
__hidinput_change_resolution_multipliers() and an out-of-bounds read in
hidinput_count_leds().

To fix this, let's make sure that both the usage and value arrays are
the same size.

Cc: stable@vger.kernel.org
Signed-off-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Change-Id: I3cab1be4009354f7ab426e6aa5b9384bc4419781
Git-commit: ed9be64eefe26d7d8b0b5b9fa3ffdf425d87a01f
Git-repo: https://android.googlesource.com/kernel/common


Signed-off-by: Uppala Revanth Kumar <urevanth@codeaurora.org>

parent d1e4dff4

drivers/hid/hid-core.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -91,7 +91,7 @@ EXPORT_SYMBOL_GPL(hid_register_report);
		* Register a new field for this report.
		*/

		static struct hid_field hid_register_field(struct hid_report report, unsigned usages, unsigned values)
		static struct hid_field hid_register_field(struct hid_report report, unsigned usages)
		{
		struct hid_field *field;

		@@ -102,7 +102,7 @@ static struct hid_field hid_register_field(struct hid_report report, unsigned

		field = kzalloc((sizeof(struct hid_field) +
		usages * sizeof(struct hid_usage) +
		values * sizeof(unsigned)), GFP_KERNEL);
		usages * sizeof(unsigned)), GFP_KERNEL);
		if (!field)
		return NULL;

		@@ -281,7 +281,7 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
		usages = max_t(unsigned, parser->local.usage_index,
		parser->global.report_count);

		field = hid_register_field(report, usages, parser->global.report_count);
		field = hid_register_field(report, usages);
		if (!field)
		return 0;