[libvirt] [PATCHv2] Ignore bridge template names with multiple printf conversions

For some reason, we allow a bridge name with %d in it, which we replace with an unsigned integer to form a bridge name that does not yet exist on the host. Do not blindly pass it to virAsprintf if it's not the only conversion, to prevent crashing on input like: <network> <name>test</name> <forward mode='none'/> <bridge name='virbr%d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s'/> </network> Ignore any template strings that do not have exactly one %d conversion, like we do in various drivers before calling virNetDevTapCreateInBridgePort. --- v2: drop the unnecessary changes in networkBridgeNameValidate src/network/bridge_driver.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 3b879cd..fe2448d 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -2775,7 +2775,13 @@ networkFindUnusedBridgeName(virNetworkObjListPtr nets, int ret = -1, id = 0; char *newname = NULL; - const char *templ = def->bridge ? def->bridge : "virbr%d"; + const char *templ = "virbr%d"; + const char *p; + + if (def->bridge && + (p = strchr(def->bridge, '%')) == strrchr(def->bridge, '%') && + strstr(def->bridge, "%d")) + templ = def->bridge; do { if (virAsprintf(&newname, templ, id) < 0) -- 2.0.5