systemd: network: don't return allocated buffer of zero length from deserialize_in_addrs()

Imported from systemd:

    deserialize_in_addrs() allocates the buffer before trying to parse
    the IP address. Since a parsing error is silently ignored, the returned
    size might be zero. In such a case we shouldn't return any buffer.

    Anyway, there was no leak, because there are only two callers like

        r = deserialize_in_addrs(&lease->dns, dns);

    which both keep the unused buffer and later release it.

    Note that deserialize_in_addrs() doesn't free the pointer before
    reassigning the new output. The caller must take care to to pass
    "ret" with an allocated buffer that would be leaked when returning
    the result.

https://github.com/systemd/systemd/commit/c24b68216222156a45c5a8a918e7a44c144e9555

1 files changed, 1 insertions, 1 deletions

diff --git a/src/systemd/src/libsystemd-network/network-internal.c b/src/systemd/src/libsystemd-network/network-internal.c
index f03a30f4b3..cee1085312 100644
--- a/src/systemd/src/libsystemd-network/network-internal.c
+++ b/src/systemd/src/libsystemd-network/network-internal.c
@@ -456,7 +456,7 @@ int deserialize_in_addrs(struct in_addr **ret, const char *string) {
                 size++;
         }
 
-        *ret = TAKE_PTR(addresses);
+        *ret = size > 0 ? TAKE_PTR(addresses) : NULL;
 
         return size;
 }