From 0373615579c7359dfd0bc66139c2e7bf67793480 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 31 Jan 2007 17:58:29 +0200 Subject: [MTD] [NAND] Correctly validate out-of-band offset and length Add checks to ensure that out-of-band reads and writes are not attempted with an invalid offset or length. Specifically, the offset must be less than the size of oob for a page and the length must not go beyond the size of the device. Additionally the checks must adjust for auto-placement (MTD_OOB_AUTO) of oob data. Signed-off-by: Adrian Hunter Signed-off-by: David Woodhouse --- drivers/mtd/nand/nand_base.c | 46 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 41 insertions(+), 5 deletions(-) (limited to 'drivers/mtd') diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index dfe56e03e48b..c13d66426360 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -1272,10 +1272,25 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from, DEBUG(MTD_DEBUG_LEVEL3, "nand_read_oob: from = 0x%08Lx, len = %i\n", (unsigned long long)from, readlen); - if (ops->mode == MTD_OOB_RAW) - len = mtd->oobsize; - else + if (ops->mode == MTD_OOB_AUTO) len = chip->ecc.layout->oobavail; + else + len = mtd->oobsize; + + if (unlikely(ops->ooboffs >= len)) { + DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: " + "Attempt to start read outside oob\n"); + return -EINVAL; + } + + /* Do not allow reads past end of device */ + if (unlikely(from >= mtd->size || + ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) - + (from >> chip->page_shift)) * len)) { + DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: " + "Attempt read beyond end of device\n"); + return -EINVAL; + } chipnr = (int)(from >> chip->chip_shift); chip->select_chip(mtd, chipnr); @@ -1742,19 +1757,40 @@ static int nand_write(struct mtd_info *mtd, loff_t to, size_t len, static int nand_do_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops) { - int chipnr, page, status; + int chipnr, page, status, len; struct nand_chip *chip = mtd->priv; DEBUG(MTD_DEBUG_LEVEL3, "nand_write_oob: to = 0x%08x, len = %i\n", (unsigned int)to, (int)ops->ooblen); + if (ops->mode == MTD_OOB_AUTO) + len = chip->ecc.layout->oobavail; + else + len = mtd->oobsize; + /* Do not allow write past end of page */ - if ((ops->ooboffs + ops->ooblen) > mtd->oobsize) { + if ((ops->ooboffs + ops->ooblen) > len) { DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: " "Attempt to write past end of page\n"); return -EINVAL; } + if (unlikely(ops->ooboffs >= len)) { + DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: " + "Attempt to start write outside oob\n"); + return -EINVAL; + } + + /* Do not allow reads past end of device */ + if (unlikely(to >= mtd->size || + ops->ooboffs + ops->ooblen > + ((mtd->size >> chip->page_shift) - + (to >> chip->page_shift)) * len)) { + DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: " + "Attempt write beyond end of device\n"); + return -EINVAL; + } + chipnr = (int)(to >> chip->chip_shift); chip->select_chip(mtd, chipnr); -- cgit v1.2.3