When the "-n" option is given, jackd crashes when accessing
properties (which it seems to do implicitly for any client, e.g.
jack_lsp).
To reproduce:
jackd -nfoo -dalsa
or
JACK_DEFAULT_SERVER=bar jackd -nfoo -dalsa
While jackd is running, repeat this:
JACK_DEFAULT_SERVER=foo jack_lsp
After a few tries, jackd crashes:
/dev/shm/jack-0/default/__db.001: No such file or directory
cannot open DB environment: No such file or directory
Segmentation fault
I found several problems in the code:
- jack_property_init():
Returns early if db_env != NULL. However, on failure later returns
with db_env != NULL, but db == NULL. Callers assume db != NULL
after it returns.
Patch below. This fixes at least the segfault, but the error
message remains (and whatever consequences it may have, I don't
know).
- 7 places in metadata.c:
if (jack_property_init (NULL)) {
If NULL is passed for server_name, of course it won't use the
actual server name.
How is this supposed to work at all? Was it ever tested?
A fix should consist of passing the actual server name from the
callers.
--- libjack/metadata.c
+++ libjack/metadata.c
@@ -45,11 +45,11 @@
/* idempotent */
- if (db_env) {
+ if (db) {
return 0;
}
- if ((ret = db_env_create(&db_env, 0)) != 0) {
+ if (!db_env && (ret = db_env_create(&db_env, 0)) != 0) {
jack_error ("cannot initialize DB environment: %s\n", db_strerror(ret));
return -1;
}