From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from youngberry.canonical.com ([91.189.89.112]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1eCSZV-0001KV-SF for linux-mtd@lists.infradead.org; Wed, 08 Nov 2017 15:47:23 +0000 From: Colin King To: David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Andrea Adami , linux-mtd@lists.infradead.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][mtd-next] mtd: sharpslpart: fix overflow on block_adr calculation Date: Wed, 8 Nov 2017 15:46:49 +0000 Message-Id: <20171108154649.30096-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Colin Ian King Multiplying block_num and mtd->erasesize may potentially overflow as they are both unsigned ints and so the multiplication is evaluated in unsigned int arithmetic . Cast block_adr to off_t to ensure multiplication is off_t sized to avoid any potential overflow. Detected by CoverityScan, CID#1461264 ("Unintentional integer overflow") Fixes: fff1e32a50c0 ("mtd: sharpslpart: Add sharpslpart partition parser") Signed-off-by: Colin Ian King --- drivers/mtd/parsers/sharpslpart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/parsers/sharpslpart.c b/drivers/mtd/parsers/sharpslpart.c index 5fe0079ea5ed..b1d97aa3bac4 100644 --- a/drivers/mtd/parsers/sharpslpart.c +++ b/drivers/mtd/parsers/sharpslpart.c @@ -244,7 +244,7 @@ static int sharpsl_nand_read_laddr(struct mtd_info *mtd, return -EINVAL; block_num = ftl->log2phy[log_num]; - block_adr = block_num * mtd->erasesize; + block_adr = (loff_t)block_num * mtd->erasesize; block_ofs = mtd_mod_by_eb((u32)from, mtd); err = mtd_read(mtd, block_adr + block_ofs, len, &retlen, buf); -- 2.14.1