From mboxrd@z Thu Jan 1 00:00:00 1970 From: Miquel Raynal Date: Wed, 1 Aug 2018 10:18:24 +0200 Subject: [U-Boot] [PATCH v6 03/27] mtd: Add sanity checks in mtd_write/read_oob() In-Reply-To: <20180801081848.19398-1-miquel.raynal@bootlin.com> References: <20180801081848.19398-1-miquel.raynal@bootlin.com> Message-ID: <20180801081848.19398-4-miquel.raynal@bootlin.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de From: Boris Brezillon Unlike what's done in mtd_read/write(), there are no checks to make sure the parameters passed to mtd_read/write_oob() are consistent, which forces implementers of ->_read/write_oob() to do it, which in turn leads to code duplication and possibly errors in the logic. Do general sanity checks, like ops fields consistency and range checking. Signed-off-by: Boris Brezillon Cc: Peter Pan Signed-off-by: Richard Weinberger [Miquel: squashed the fix about the chip's size check] Signed-off-by: Miquel Raynal --- drivers/mtd/mtdcore.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index ad61406dac..9a3efe95df 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -1010,12 +1010,50 @@ int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, } EXPORT_SYMBOL_GPL(mtd_panic_write); +static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs, + struct mtd_oob_ops *ops) +{ + /* + * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving + * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in + * this case. + */ + if (!ops->datbuf) + ops->len = 0; + + if (!ops->oobbuf) + ops->ooblen = 0; + + if (offs < 0 || offs + ops->len > mtd->size) + return -EINVAL; + + if (ops->ooblen) { + u64 maxooblen; + + if (ops->ooboffs >= mtd_oobavail(mtd, ops)) + return -EINVAL; + + maxooblen = ((mtd_div_by_ws(mtd->size, mtd) - + mtd_div_by_ws(offs, mtd)) * + mtd_oobavail(mtd, ops)) - ops->ooboffs; + if (ops->ooblen > maxooblen) + return -EINVAL; + } + + return 0; +} + int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) { int ret_code; ops->retlen = ops->oobretlen = 0; if (!mtd->_read_oob) return -EOPNOTSUPP; + + ret_code = mtd_check_oob_ops(mtd, from, ops); + if (ret_code) + return ret_code; + /* * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics * similar to mtd->_read(), returning a non-negative integer @@ -1034,11 +1072,18 @@ EXPORT_SYMBOL_GPL(mtd_read_oob); int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops) { + int ret; + ops->retlen = ops->oobretlen = 0; if (!mtd->_write_oob) return -EOPNOTSUPP; if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; + + ret = mtd_check_oob_ops(mtd, to, ops); + if (ret) + return ret; + return mtd->_write_oob(mtd, to, ops); } EXPORT_SYMBOL_GPL(mtd_write_oob); -- 2.14.1