From: Bryan O'Donoghue Date: Fri, 28 Jul 2017 13:22:57 +0000 (+0100) Subject: mtd: nand: sunxi: fix potential divide-by-zero error X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=791eccd94965a8029ae09c5530bcb9a76794e408;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git mtd: nand: sunxi: fix potential divide-by-zero error clk_round_rate() can return <= 0. Currently the value returned by clk_round_rate() is used directly for a division. This patch introduces a guard to ensure a divide-by-zero or a divide by a negative number for that matter can't happen by bugging out returning -EINVAL if clk_round_rate() returns <= 0. Fixes: 2d43457f79e4 ("mtd: nand: sunxi: fix EDO mode selection") Signed-off-by: Bryan O'Donoghue Signed-off-by: Boris Brezillon --- diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c index d0b6f8f9f297..6abd142b1324 100644 --- a/drivers/mtd/nand/sunxi_nand.c +++ b/drivers/mtd/nand/sunxi_nand.c @@ -1728,6 +1728,10 @@ static int sunxi_nfc_setup_data_interface(struct mtd_info *mtd, int csline, */ chip->clk_rate = NSEC_PER_SEC / min_clk_period; real_clk_rate = clk_round_rate(nfc->mod_clk, chip->clk_rate); + if (real_clk_rate <= 0) { + dev_err(nfc->dev, "Unable to round clk %lu\n", chip->clk_rate); + return -EINVAL; + } /* * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data