mtd: bcm47xxpart: avoid overflowing when registering trx

Our code parsing "trx" header registers few partitions at once (in one
loop iteration). Add extra check in that place.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/mtd/bcm47xxpart.c b/drivers/mtd/bcm47xxpart.c
index e388e69d853e..23d712209b98 100644
--- a/drivers/mtd/bcm47xxpart.c
+++ b/drivers/mtd/bcm47xxpart.c
@@ -147,6 +147,11 @@ static int bcm47xxpart_parse(struct mtd_info *master,
 
                 /* TRX */
                 if (buf[0x000 / 4] == TRX_MAGIC) {
+                        if (BCM47XXPART_MAX_PARTS - curr_part < 4) {
+                                pr_warn("Not enough partitions left to register trx, scanning stopped!\n");
+                                break;
+                        }
+
                         trx = (struct trx_header *)buf;
 
                         trx_part = curr_part;