Fix RPC server memory leaks

Resolves: rhbz#1946950

Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
This commit is contained in:
Alexander Bokovoy 2021-04-07 18:05:51 +03:00
parent b05e4ed148
commit d08e5bf692
2 changed files with 163 additions and 1 deletions

157
samba-bz14675-fix.patch Normal file
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@ -0,0 +1,157 @@
From 75a66ce1da41c5b081771b2db55c2994d378d882 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow@samba.org>
Date: Tue, 23 Mar 2021 11:40:21 +0100
Subject: [PATCH 1/3] 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 ${pipename}_op_dispatch_internal() function which is a
dcesrv_call_state object created by dcesrv_process_ncacn_packet() and released
by the RPC server when the RPC request processing is finished.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14675
CI: https://gitlab.com/samba-team/samba/-/merge_requests/1861
Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
(cherry picked from commit 4c3fb2a5912966a61e7ebdb05eb3231a0e1d6033)
---
pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm | 2 ++
source3/rpc_server/rpc_handles.c | 6 ------
2 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm b/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm
index 54feea0a9ef..d1368c3dbca 100644
--- a/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm
+++ b/pidl/lib/Parse/Pidl/Samba4/NDR/ServerCompat.pm
@@ -299,6 +299,7 @@ sub boilerplate_iface($)
$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 45968746440..9ef93231466 100644
--- 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;
--
2.30.2
From 33a7749f7fc5c58752815789d086d696a20878e7 Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow@samba.org>
Date: Mon, 22 Mar 2021 12:06:39 +0100
Subject: [PATCH 2/3] spools: avoid leaking memory into the callers mem_ctx
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>
(cherry picked from commit 481176ec745c14b78fca68e01a61c83405a4b97b)
---
source3/rpc_server/spoolss/srv_spoolss_nt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/source3/rpc_server/spoolss/srv_spoolss_nt.c b/source3/rpc_server/spoolss/srv_spoolss_nt.c
index d20c19d5271..24ea7367ec8 100644
--- a/source3/rpc_server/spoolss/srv_spoolss_nt.c
+++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c
@@ -5731,7 +5731,8 @@ static WERROR construct_printer_driver_info_level(TALLOC_CTX *mem_ctx,
}
if (pinfo2->drivername == NULL || pinfo2->drivername[0] == '\0') {
- return WERR_UNKNOWN_PRINTER_DRIVER;
+ result = WERR_UNKNOWN_PRINTER_DRIVER;
+ goto done;
}
DBG_INFO("Construct printer driver [%s] for [%s]\n",
@@ -7023,7 +7024,8 @@ static WERROR update_printer(struct pipes_struct *p,
raddr = tsocket_address_inet_addr_string(p->remote_address,
p->mem_ctx);
if (raddr == NULL) {
- return WERR_NOT_ENOUGH_MEMORY;
+ result = WERR_NOT_ENOUGH_MEMORY;
+ goto done;
}
/* add_printer_hook() will call reload_services() */
--
2.30.2
From 602290d48d3bc49acca64a089822f26da293ee1e Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl@samba.org>
Date: Tue, 23 Mar 2021 17:06:15 +0100
Subject: [PATCH 3/3] rpc_server3: Fix a memleak for internal pipes
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
state->call should not be talloc'ed off a long-lived context
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14675
CI: https://gitlab.com/samba-team/samba/-/merge_requests/1861
RN: Memory leak in the RPC server
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Samuel Cabrero <scabrero@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
Autobuild-User(master): Ralph Böhme <slow@samba.org>
Autobuild-Date(master): Wed Mar 31 12:14:01 UTC 2021 on sn-devel-184
(cherry picked from commit 12f516e4680753460e7fe8811e6c6ff70057580c)
---
source3/rpc_server/rpc_ncacn_np.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/source3/rpc_server/rpc_ncacn_np.c b/source3/rpc_server/rpc_ncacn_np.c
index 9ba271c2479..494b002e714 100644
--- a/source3/rpc_server/rpc_ncacn_np.c
+++ b/source3/rpc_server/rpc_ncacn_np.c
@@ -476,7 +476,7 @@ static struct tevent_req *rpcint_bh_raw_call_send(TALLOC_CTX *mem_ctx,
return tevent_req_post(req, ev);
}
- state->call = talloc_zero(hs->conn, struct dcesrv_call_state);
+ state->call = talloc_zero(state, struct dcesrv_call_state);
if (tevent_req_nomem(state->call, req)) {
return tevent_req_post(req, ev);
}
--
2.30.2

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@ -108,7 +108,7 @@
%define samba_requires_eq() %(LC_ALL="C" echo '%*' | xargs -r rpm -q --qf 'Requires: %%{name} = %%{epoch}:%%{version}\\n' | sed -e 's/ (none):/ /' -e 's/ 0:/ /' | grep -v "is not")
%global main_release 0
%global main_release 1
%global samba_version 4.14.2
%global talloc_version 2.3.2
@ -177,6 +177,7 @@ Source14: samba.pamd
Source201: README.downgrade
Patch1: samba-s4u.patch
Patch2: samba-bz14675-fix.patch
Requires(pre): /usr/sbin/groupadd
Requires(post): systemd
@ -3839,6 +3840,10 @@ fi
%endif
%changelog
* Wed Apr 07 2021 Alexander Bokovoy <abokovoy@redhat.com> - 4.14.2-1
- Fix memory leaks in RPC server
- resolves: #1946950
* Thu Mar 25 2021 Guenther Deschner <gdeschner@redhat.com> - 4.14.2-0
- Update to Samba 4.14.2
- related: #1941400, #1942496 - Security fixes for CVE-2020-27840