[libvirt] [PATCH] rpc: libssh: don't crash when known_hosts file path is not provided

When connecting as root, the "hostsfile" variable would be NULL due to the code leading to this point. This would result into a crash when attempting to set the known hosts file path. To avoid deviating from the approach taken in the libssh2 driver set the file to /dev/null so that all entries are discarded unless explicitly specified. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1406457 --- Note that it would be much simpler just to skip ssh_options_set if 'hostsfile' is NULL. This would result in using /root/.ssh/known_hosts (according to the config) which would be different to the approach taken in libssh2. With libssh2 this can't be done (at least the last time I checked) as it happened to corrupt the file in some cases. src/rpc/virnetlibsshsession.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/rpc/virnetlibsshsession.c b/src/rpc/virnetlibsshsession.c index 5de6629d7..5fc16ba8a 100644 --- a/src/rpc/virnetlibsshsession.c +++ b/src/rpc/virnetlibsshsession.c @@ -1172,6 +1172,9 @@ virNetLibsshSessionSetHostKeyVerification(virNetLibsshSessionPtr sess, goto error; } + if (!hostsfile) + hostsfile = "/dev/null"; + /* set the known hosts file */ if (ssh_options_set(sess->session, SSH_OPTIONS_KNOWNHOSTS, hostsfile) < 0) goto error; -- 2.11.0