From 433135c85c521aa9119b8ad1343eb70973c58f21 Mon Sep 17 00:00:00 2001 From: Zahari Doychev Date: Tue, 8 Jul 2014 09:37:35 +0200 Subject: [PATCH] drivers/mtd: fix NULL pointer dereference in partition lock/unlock Some mtd device does not support lock and unlock functions. Adding this check avoids crashing when mtd_part_lock/unlock are called for such devices. Signed-off-by: Zahari Doychev Signed-off-by: Sascha Hauer --- drivers/mtd/partition.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/mtd/partition.c b/drivers/mtd/partition.c index 9b2b20ef5..e393fa68f 100644 --- a/drivers/mtd/partition.c +++ b/drivers/mtd/partition.c @@ -51,6 +51,9 @@ static int mtd_part_erase(struct mtd_info *mtd, struct erase_info *instr) static int mtd_part_lock(struct mtd_info *mtd, loff_t offset, size_t len) { + if (!mtd->master->lock) + return -ENOSYS; + if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS; @@ -64,6 +67,9 @@ static int mtd_part_lock(struct mtd_info *mtd, loff_t offset, size_t len) static int mtd_part_unlock(struct mtd_info *mtd, loff_t offset, size_t len) { + if (!mtd->master->unlock) + return -ENOSYS; + if (!(mtd->flags & MTD_WRITEABLE)) return -EROFS;