sd-id128: check that the kernel is feeding us proper data

The characters are already checked, so we show that
we don't trust the kernel. Make sure we don't overrun
the buffer too.

diff --git a/src/libsystemd-id128/sd-id128.c b/src/libsystemd-id128/sd-id128.c
index 4286ae7d146027b40b03378151387d8f8d0a4a1e..68c4987149d5ead483f5e803cd47a884a8890010 100644 (file)
--- a/src/libsystemd-id128/sd-id128.c
+++ b/src/libsystemd-id128/sd-id128.c
@@ -170,6 +170,9 @@ _public_ int sd_id128_get_boot(sd_id128_t *ret) {
         for (j = 0, p = buf; j < 16; j++) {
                 int a, b;
 
+                if (p >= buf + k)
+                        return -EIO;
+
                 if (*p == '-')
                         p++;