mtd: check parts pointer before using it

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=4d523b60ef9d1953d9e12745ca0ed3e2dc98c189
Commit:     4d523b60ef9d1953d9e12745ca0ed3e2dc98c189
Parent:     e2e24e8ebf0e96571fbbac95c215df6a2cebbc5b
Author:     Jason Liu <jason.hui at linaro.org>
AuthorDate: Wed Aug 24 19:26:28 2011 +0800
Committer:  Artem Bityutskiy <artem.bityutskiy at intel.com>
CommitDate: Sun Sep 11 15:02:18 2011 +0300

    mtd: check parts pointer before using it
    
    The code has the check for parts but it called after kmemdup,
    kmemdup(parts, sizeof(*parts) * nr_parts,...)
    if (!parts)
    	return -ENOMEM
    
    In fact, we need check parts before safely using it.
    and we also need check the real_parts to make sure kmemdup
    allocation sucessfully.
    
    Signed-off-by: Jason Liu <jason.hui at linaro.org>
    Signed-off-by: Artem Bityutskiy <artem.bityutskiy at intel.com>
---
 drivers/mtd/mtdcore.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 09bdbac..b01993e 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -465,12 +465,13 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char **types,
 	struct mtd_partition *real_parts;
 
 	err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
-	if (err <= 0 && nr_parts) {
+	if (err <= 0 && nr_parts && parts) {
 		real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
 				     GFP_KERNEL);
-		err = nr_parts;
-		if (!parts)
+		if (!real_parts)
 			err = -ENOMEM;
+		else
+			err = nr_parts;
 	}
 
 	if (err > 0) {