mtd: partitions: redboot: Added conversion of operands to a larger type

Denis Arefev · miquelraynal · commit 1162bc2f8f5d · 2024-03-25T11:17:16.000+01:00
The value of an arithmetic expression directory * master->erasesize is subject to overflow due to a failure to cast operands to a larger data type before perfroming arithmetic Found by Linux Verification Center (linuxtesting.org) with SVACE. Signed-off-by: Denis Arefev <arefev@swemel.ru> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20240315093758.20790-1-arefev@swemel.ru
diff --git a/drivers/mtd/parsers/redboot.c b/drivers/mtd/parsers/redboot.c
@@ -102,7 +102,7 @@ static int parse_redboot_partitions(struct mtd_info *master,
 			offset -= master->erasesize;
 		}
 	} else {
-		offset = directory * master->erasesize;
+		offset = (unsigned long) directory * master->erasesize;
 		while (mtd_block_isbad(master, offset)) {
 			offset += master->erasesize;
 			if (offset == master->size)

Original file line number	Diff line number	Diff line change
`@@ -102,7 +102,7 @@ static int parse_redboot_partitions(struct mtd_info *master,`
`102`	`102`	`offset -= master->erasesize;`
`103`	`103`	`}`
`104`	`104`	`} else {`
`105`		`- offset = directory * master->erasesize;`
	`105`	`+ offset = (unsigned long) directory * master->erasesize;`
`106`	`106`	`while (mtd_block_isbad(master, offset)) {`
`107`	`107`	`offset += master->erasesize;`
`108`	`108`	`if (offset == master->size)`