@@ -1107,6 +1107,39 @@ 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;
@@ -1114,6 +1147,10 @@ int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
if (!mtd->_read_oob)
return -EOPNOTSUPP;
+ ret_code = mtd_check_oob_ops(mtd, from, ops);
+ if (ret_code)
+ return ret_code;
+
ledtrig_mtd_activity();
/*
* In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
@@ -1133,11 +1170,18 @@ 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;
+
ledtrig_mtd_activity();
return mtd->_write_oob(mtd, to, ops);
}
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 <boris.brezillon@free-electrons.com> Cc: Peter Pan <peterpandong@micron.com> --- Hi Peter, This patch is meant to replace https://patchwork.ozlabs.org/patch/766337/. Note that I changed my mind regarding the "do not fix inconsistent ->ooblen/oobuf and ->len/datbuf and return an error" solution. It seems that all users assume that ->datbuf = NULL implies ->len = 0 and ->oobbuf = NULL implies ->ooblen = 0, so I decided to silently fix ->[oob]len and ->dat/oobbuf mismatch in the mtd_check_oob_ops() helper instead. Regards, Boris --- drivers/mtd/mtdcore.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)