pidl: set the per-request memory context in the pidl generator

The talloc memory context referenced by the pipe_struct mem_ctx member is used
as talloc parent for RPC response data by the RPC service implementations.

In Samba versions up to 4.10 all talloc children of p->mem_ctx were freed after
a RPC response was delivered by calling talloc_free_children(p->mem_ctx). Commit
60fa8e255254d38e9443bf96f2c0f31430be6ab8 removed this call which resulted in all
memory allocations on this context not getting released, which can consume
significant memory in long running RPC connections.

Instead of putting the talloc_free_children(p->mem_ctx) back, just use the
mem_ctx argument of the ${pipename}_op_dispatch_internal() function which is a
dcesrv_call_state object created by dcesrv_process_ncacn_packet() and released
by the RPC server when the RPC request processing is finished.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14675
CI: https://gitlab.com/samba-team/samba/-/merge_requests/1861

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

diff --git a/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm b/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm
index 54feea0a9ef15b46f8db0957c63cd3595e15fcd8..d1368c3dbcaae34a49fe6b47d4983f37961bd2d4 100644 (file)
--- a/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm
+++ b/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm
@@ -299,6 +299,7 @@ sub boilerplate_iface($)
        $self->pidl("/* Update pipes struct opnum */");
        $self->pidl("p->opnum = opnum;");
        $self->pidl("p->dce_call = dce_call;");
+       $self->pidl("p->mem_ctx = mem_ctx;");
        $self->pidl("/* Update pipes struct session info */");
        $self->pidl("pipe_session_info = p->session_info;");
        $self->pidl("p->session_info = dce_call->auth_state->session_info;");
@@ -344,6 +345,7 @@ sub boilerplate_iface($)
        $self->pidl("");
 
        $self->pidl("p->dce_call = NULL;");
+       $self->pidl("p->mem_ctx = NULL;");
        $self->pidl("/* Restore session info */");
        $self->pidl("p->session_info = pipe_session_info;");
        $self->pidl("p->auth.auth_type = 0;");

diff --git a/source3/rpc_server/rpc_handles.c b/source3/rpc_server/rpc_handles.c
index 459687464401e317b9c828f19708b1ea78d3c04c..9ef93231466c6b99a692dd988cdb0e68bc0c4b86 100644 (file)
--- a/source3/rpc_server/rpc_handles.c
+++ b/source3/rpc_server/rpc_handles.c
@@ -60,12 +60,6 @@ int make_base_pipes_struct(TALLOC_CTX *mem_ctx,
                return ENOMEM;
        }
 
-       p->mem_ctx = talloc_named(p, 0, "pipe %s %p", pipe_name, p);
-       if (!p->mem_ctx) {
-               talloc_free(p);
-               return ENOMEM;
-       }
-
        p->msg_ctx = msg_ctx;
        p->transport = transport;