[PATCH 4.19 001/247] HID: make arrays usage and value to be the same
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-03-01 19:45:19
Also in:
lkml
From: Will McVicker <redacted> commit ed9be64eefe26d7d8b0b5b9fa3ffdf425d87a01f upstream. 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 <redacted> Signed-off-by: Jiri Kosina <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/hid/hid-core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c@@ -93,7 +93,7 @@ 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;
@@ -104,7 +104,7 @@ static struct hid_field *hid_register_fi 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;
@@ -300,7 +300,7 @@ static int hid_add_field(struct hid_pars 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;