From 5d53244186c9ac58cb88d76a0958ca55b83a15cd Mon Sep 17 00:00:00 2001 From: William Zhang Date: Thu, 6 Jul 2023 11:29:08 -0700 Subject: [PATCH] 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. Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller") Signed-off-by: William Zhang Reviewed-by: Florian Fainelli Cc: stable@vger.kernel.org Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230706182909.79151-5-william.zhang@broadcom.com --- 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 b2c6396..71d0ba6 100644 --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c @@ -1477,19 +1477,33 @@ 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; } -- 2.7.4