Add checking return values of snprintf

Change-Id: If38a743334fda4f7f8b697ff9f24ce1531caa6b4
Signed-off-by: Junghyun Yeon <jungh.yeon@samsung.com>

diff --git a/plugin/app2sd/server/app2sd_internals.c b/plugin/app2sd/server/app2sd_internals.c
index a98102d..c093ece 100644 (file)
--- a/plugin/app2sd/server/app2sd_internals.c
+++ b/plugin/app2sd/server/app2sd_internals.c
@@ -184,15 +184,23 @@ int _app2sd_dmcrypt_open_device(const char *pkgid, const char *loopback_device,
 
        if (_app2sd_check_is_luks_device(loopback_device) == 0) {
                _W("legacy image format!");
-               snprintf(dmcrypt_open_cmd, sizeof(dmcrypt_open_cmd),
+               ret = snprintf(dmcrypt_open_cmd, sizeof(dmcrypt_open_cmd),
                                "/bin/echo '%s' | /sbin/cryptsetup "
                                "-M plain -c aes-cbc-plain -h plain open %s %s",
                                passwd, loopback_device, dev_name);
+               if (ret < 0 || ret > sizeof(dmcrypt_open_cmd)) {
+                       _E("snprintf fail\n");
+                       return -1;
+               }
        } else {
-               snprintf(dmcrypt_open_cmd, sizeof(dmcrypt_open_cmd),
+               ret = snprintf(dmcrypt_open_cmd, sizeof(dmcrypt_open_cmd),
                                "/bin/echo '%s' | /sbin/cryptsetup -q luksOpen "
                                "%s %s",
                                passwd, loopback_device, dev_name);
+               if (ret < 0 || ret > sizeof(dmcrypt_open_cmd)) {
+                       _E("snprintf fail\n");
+                       return -1;
+               }
        }
        free(passwd);
 
@@ -209,9 +217,12 @@ int _app2sd_dmcrypt_open_device(const char *pkgid, const char *loopback_device,
                _E("memory alloc failed");
                return APP2EXT_ERROR_OPEN_DMCRYPT_DEVICE;
        }
-       snprintf(*dev_node, size, "/dev/mapper/%s", dev_name);
-
-       return ret;
+       ret = snprintf(*dev_node, size, "/dev/mapper/%s", dev_name);
+       if (ret < 0 || ret > size) {
+                       _E("snprintf fail\n");
+                       return -1;
+       }
+       return 0;
 }
 
 int _app2sd_dmcrypt_close_device(const char *pkgid, uid_t uid)
@@ -236,9 +247,17 @@ int _app2sd_dmcrypt_close_device(const char *pkgid, uid_t uid)
 
        free(t_dev_node);
 
-       snprintf(dev_node, sizeof(dev_node), "/dev/mapper/%s_%d", pkgid, uid);
-       snprintf(dmcrypt_close_cmd, sizeof(dmcrypt_close_cmd),
+       ret = snprintf(dev_node, sizeof(dev_node), "/dev/mapper/%s_%d", pkgid, uid);
+       if (ret < 0 || ret > sizeof(dev_node)) {
+               _E("snprintf fail");
+               return APP2EXT_ERROR_CLOSE_DMCRYPT_DEVICE;
+       }
+       ret = snprintf(dmcrypt_close_cmd, sizeof(dmcrypt_close_cmd),
                        "/sbin/cryptsetup -q luksClose %s", dev_node);
+       if (ret < 0 || ret > sizeof(dmcrypt_close_cmd)) {
+               _E("snprintf fail");
+               return APP2EXT_ERROR_CLOSE_DMCRYPT_DEVICE;
+       }
        ret = system(dmcrypt_close_cmd);
        if (ret) {
                err_str = strerror_r(errno, err_buf, sizeof(err_buf));