net/colo: Fix a "double free" crash to clear the conn_list

We notice the QEMU may crash when the guest has too many
incoming network connections with the following log:

15197@1593578622.668573:colo_proxy_main : colo proxy connection hashtable full, clear it
free(): invalid pointer
[1]    15195 abort (core dumped)  qemu-system-x86_64 ....

This is because we create the s->connection_track_table with
g_hash_table_new_full() which is defined as:

GHashTable * g_hash_table_new_full (GHashFunc hash_func,
                       GEqualFunc key_equal_func,
                       GDestroyNotify key_destroy_func,
                       GDestroyNotify value_destroy_func);

The fourth parameter connection_destroy() will be called to free the
memory allocated for all 'Connection' values in the hashtable when
we call g_hash_table_remove_all() in the connection_hashtable_reset().

But both connection_track_table and conn_list reference to the same
conn instance. It will trigger double free in conn_list clear. So this
patch remove free action on hash table side to avoid double free the
conn.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Zhang Chen 2022-04-01 11:47:00 +08:00 committed by Jason Wang
parent 669846c530
commit a18d436954
2 changed files with 2 additions and 2 deletions

View File

@ -1323,7 +1323,7 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
s->connection_track_table = g_hash_table_new_full(connection_key_hash,
connection_key_equal,
g_free,
connection_destroy);
NULL);
colo_compare_iothread(s);

View File

@ -383,7 +383,7 @@ static void colo_rewriter_setup(NetFilterState *nf, Error **errp)
s->connection_track_table = g_hash_table_new_full(connection_key_hash,
connection_key_equal,
g_free,
connection_destroy);
NULL);
s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
}