From 32bcf7c1eea953155d75319eddeb574549cc7585 Mon Sep 17 00:00:00 2001 From: William Zhang Date: Mon, 16 Sep 2024 11:58:45 +0200 Subject: [PATCH] mtd: rawnand: brcmnand: Fix potential out-of-bounds access in oob write Backport of upstream Linux commit 5d53244186c9ac58cb88d76a0958ca55b83a15cd "mtd: rawnand: brcmnand: Fix potential out-of-bounds access in oob write" When the oob buffer length is not in multiple of words, the oob write function does out-of-bounds read on the oob source buffer at the last iteration. Fix that by always checking length limit on the oob buffer read and fill with 0xff when reaching the end of the buffer to the oob registers. Signed-off-by: William Zhang Reviewed-by: Florian Fainelli Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230706182909.79151-5-william.zhang@broadcom.com Signed-off-by: Linus Walleij Reviewed-by: William Zhang --- drivers/mtd/nand/raw/brcmnand/brcmnand.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c index 46a4107a83..60d34bd21f 100644 --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c @@ -1334,19 +1334,33 @@ static int write_oob_to_regs(struct brcmnand_controller *ctrl, int i, const u8 *oob, int sas, int sector_1k) { int tbytes = sas << sector_1k; - int j; + int j, k = 0; + u32 last = 0xffffffff; + u8 *plast = (u8 *)&last; /* Adjust OOB values for 1K sector size */ if (sector_1k && (i & 0x01)) tbytes = max(0, tbytes - (int)ctrl->max_oob); tbytes = min_t(int, tbytes, ctrl->max_oob); - for (j = 0; j < tbytes; j += 4) + /* + * tbytes may not be multiple of words. Make sure we don't read out of + * the boundary and stop at last word. + */ + for (j = 0; (j + 3) < tbytes; j += 4) oob_reg_write(ctrl, j, (oob[j + 0] << 24) | (oob[j + 1] << 16) | (oob[j + 2] << 8) | (oob[j + 3] << 0)); + + /* handle the remaing bytes */ + while (j < tbytes) + plast[k++] = oob[j++]; + + if (tbytes & 0x3) + oob_reg_write(ctrl, (tbytes & ~0x3), (__force u32)cpu_to_be32(last)); + return tbytes; } -- 2.39.5