Fix bug of mmc.c not checking read_file result.

This bug causes segment fault when reading name node of
SDIO mmc device's /sys file, which is not existed at all.

Signed-off-by: Xinyu Chen <xinyu.chen@freescale.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/vold/mmc.c b/vold/mmc.c
index fcf7c2f9..6ad97f43 100644
--- a/vold/mmc.c
+++ b/vold/mmc.c
@@ -158,6 +158,10 @@ static int mmc_bootstrap_card(char *sysfs_path)
 
     sprintf(filename, "/sys%s/name", devpath);
     p = read_file(filename, &sz);
+    if (!p) {
+        LOGE("Unable to read MMC name: %s", filename);
+        return -errno;
+    }
     p[strlen(p) - 1] = '\0';
     sprintf(tmp, "MMC_NAME=%s", p);
     free(p);