File 1159-erts-Fix-leak-in-erlang-trace-3-bif.patch of Package erlang

Overview Repositories Revisions Requests Users Attributes Meta

File 1159-erts-Fix-leak-in-erlang-trace-3-bif.patch of Package erlang (Revision 865d2e25c8b9e0a1b23f89d693ffd991)

Currently displaying revision 865d2e25c8b9e0a1b23f89d693ffd991 , Show latest

From 465cca7df433f1b3d9e310ab7ca827bb9a5c73ab Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Mon, 8 Mar 2021 21:18:27 +0100
Subject: [PATCH 2/2] erts: Fix leak in erlang:trace/3 bif

* if more than one {tracer, Pid} in list
* if {tracer, Pid} followed by invalid flag or improper list
* if {tracer, Pid} but failed to seize code write permission
---
 erts/emulator/beam/erl_bif_trace.c |  9 ++++++++-
 erts/emulator/test/trace_SUITE.erl | 12 ++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index ab42bc15f0..b688e82e70 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -465,19 +465,25 @@ erts_trace_flags(Eterm List,
 	    cpu_timestamp = !0;
 #endif
 	} else if (is_tuple(item)) {
+            ERTS_TRACER_CLEAR(&tracer);
             tracer = erts_term_to_tracer(am_tracer, item);
             if (tracer == THE_NON_VALUE)
                 goto error;
 	} else goto error;
 	list = CDR(list_val(list));
     }
-    if (is_not_nil(list)) goto error;
+    if (is_not_nil(list)) {
+        goto error;
+    }
     
     if (mask)                        *pMask         = mask;
     if (!ERTS_TRACER_IS_NIL(tracer)) *pTracer       = tracer;
     if (cpu_timestamp)               *pCpuTimestamp = cpu_timestamp;
     return !0;
+
  error:
+    if (tracer != THE_NON_VALUE)
+	ERTS_TRACER_CLEAR(&tracer);
     return 0;
 }
 
@@ -541,6 +547,7 @@ Eterm erts_internal_trace_3(BIF_ALIST_3)
     }
 
     if (!erts_try_seize_code_write_permission(BIF_P)) {
+        ERTS_TRACER_CLEAR(&tracer);
 	ERTS_BIF_YIELD3(bif_export[BIF_erts_internal_trace_3],
                         BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
     }
diff --git a/erts/emulator/test/trace_SUITE.erl b/erts/emulator/test/trace_SUITE.erl
index 025f5282fb..951502cb61 100644
--- a/erts/emulator/test/trace_SUITE.erl
+++ b/erts/emulator/test/trace_SUITE.erl
@@ -1684,6 +1684,18 @@ bad_flag(Config) when is_list(Config) ->
     {'EXIT', {badarg, _}} = (catch erlang:trace(new,
                                                 true,
                                                 [not_a_valid_flag])),
+
+    %% Leaks of {tracer,_} in OTP 23.2
+    Pid = spawn(fun() -> receive die -> ok end end),
+    1 = erlang:trace(Pid, true, [{tracer, self()},
+                                 {tracer, self()}]),
+    Pid ! die,
+    {'EXIT', {badarg, _}} =
+        (catch erlang:trace(new, true, [{tracer, self()}
+                                        | improper])),
+    {'EXIT', {badarg, _}} =
+        (catch erlang:trace(new, true, [{tracer, self()},
+                                        not_a_valid_flag])),
     ok.
 
 %% Test erlang:trace_delivered/1
-- 
2.26.2

Places

File 1159-erts-Fix-leak-in-erlang-trace-3-bif.patch of Package erlang (Revision 865d2e25c8b9e0a1b23f89d693ffd991)

Places