[PATCH master v2 2/2] hab: habv4: warn if more than 10 HAB events are found

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

The function has space for up to 10 HAB events. On the off-chance that
there are more found, it will scribble them over stack memory.

Fix this by only collecting up to 10 events and printing a warning if
that's exceeded. Once we have reports that this issue manifests, we can
consider extending the array or dynamically allocating it.

Reported-by: Christian Melki <christian.melki@t2data.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
v1 -> v2:
  - keep first 10 events found
---
 drivers/hab/habv4.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/hab/habv4.c b/drivers/hab/habv4.c
index 4db1e7cc0f3a..ed6d4db77c16 100644
--- a/drivers/hab/habv4.c
+++ b/drivers/hab/habv4.c
@@ -254,6 +254,11 @@ static enum hab_status imx8m_read_sram_events(enum hab_status status,
 			if (sram > end)
 				break;
 
+			if (num_events == ARRAY_SIZE(events)) {
+				pr_warn("Discarding excess event\n");
+				continue;
+			}
+
 			events[num_events] = search;
 			num_events++;
 		} else {
-- 
2.39.2