mmc: check find_mmc_device return value
find_mmc_device returns NULL if an invalid device number is specified.
Check for this to avoid dereferencing NULL pointers.
Signed-off-by: Rabin Vincent <rabin@rab.in>
diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c
index bd55ff1..039fe59 100644
--- a/common/cmd_mmc.c
+++ b/common/cmd_mmc.c
@@ -149,6 +149,9 @@
int dev = simple_strtoul(argv[2], NULL, 10);
struct mmc *mmc = find_mmc_device(dev);
+ if (!mmc)
+ return 1;
+
mmc_init(mmc);
return 0;
@@ -175,6 +178,9 @@
u32 blk = simple_strtoul(argv[4], NULL, 16);
struct mmc *mmc = find_mmc_device(dev);
+ if (!mmc)
+ return 1;
+
printf("\nMMC read: dev # %d, block # %d, count %d ... ",
dev, blk, cnt);
@@ -197,6 +203,9 @@
int blk = simple_strtoul(argv[4], NULL, 16);
+ if (!mmc)
+ return 1;
+
printf("\nMMC write: dev # %d, block # %d, count %d ... ",
dev, blk, cnt);
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 7791c38..70b4130 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -846,7 +846,7 @@
{
struct mmc *mmc = find_mmc_device(dev);
- return &mmc->block_dev;
+ return mmc ? &mmc->block_dev : NULL;
}
int mmc_init(struct mmc *mmc)
