[PATCH] Input: iqs5xx: validate firmware record destination span

[Pengpeng Hou]

The firmware record parser checks that the record address starts within
the programmable map, but does not check that the complete record data
fits in that map. A record near the end of the map can therefore make
the copy to pmap exceed its destination span.

Check the record length against the remaining programmable map range
before copying the record data.

Fixes: 7b5bb55d0dad ("Input: add support for Azoteq IQS550/572/525")
Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
 drivers/input/touchscreen/iqs5xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/iqs5xx.c b/drivers/input/touchscreen/iqs5xx.c
index c3cc37274335..88dcf72618df 100644
--- a/drivers/input/touchscreen/iqs5xx.c
+++ b/drivers/input/touchscreen/iqs5xx.c
@@ -785,7 +785,8 @@ static int iqs5xx_fw_file_parse(struct i2c_client *client,
 		switch (rec_type) {
 		case IQS5XX_REC_TYPE_DATA:
 			if (rec_addr < IQS5XX_CHKSM ||
-			    rec_addr > IQS5XX_PMAP_END) {
+			    rec_addr > IQS5XX_PMAP_END ||
+			    rec_len > IQS5XX_PMAP_END + 1 - rec_addr) {
 				dev_err(&client->dev,
 					"Invalid address at record %u\n",
 					rec_num);
-- 
2.43.0