Merged revisions 114208 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

................
r114208 | mmichelson | 2008-04-17 11:40:12 -0500 (Thu, 17 Apr 2008) | 20 lines

Merged revisions 114207 via svnmerge from 
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
r114207 | mmichelson | 2008-04-17 11:28:03 -0500 (Thu, 17 Apr 2008) | 12 lines

It was possible for a reference to a frame which was part of a freed DSP to still be
referenced, leading to memory corruption and eventual crashes. This code change ensures
that the dsp is freed when we are finished with the frame. This change is very similar
to a change Russell made with translators back a month or so ago.

(closes issue #11999)
Reported by: destiny6628
Patches:
      11999.patch uploaded by putnopvut (license 60)
Tested by: destiny6628, victoryure


........

................


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.6.0@114210 f38db490-d61c-443f-a65b-d21fe96a405b

2 files changed, 35 insertions, 0 deletions

diff --git a/main/dsp.c b/main/dsp.c
index 6945464d4..f24030ebb 100644
--- a/main/dsp.c
+++ b/main/dsp.c
@@ -1241,6 +1241,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 		memset(&dsp->f, 0, sizeof(dsp->f));
 		dsp->f.frametype = AST_FRAME_NULL;
 		ast_frfree(af);
+		ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 		return &dsp->f;
 	}
 	if ((dsp->features & DSP_FEATURE_BUSY_DETECT) && ast_dsp_busydetect(dsp)) {
@@ -1250,6 +1251,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 		dsp->f.subclass = AST_CONTROL_BUSY;
 		ast_frfree(af);
 		ast_debug(1, "Requesting Hangup because the busy tone was detected on channel %s\n", chan->name);
+		ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 		return &dsp->f;
 	}
 	if (((dsp->features & DSP_FEATURE_DTMF_DETECT) || (dsp->features & DSP_FEATURE_FAX_DETECT))) {
@@ -1271,6 +1273,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 					if (chan)
 						ast_queue_frame(chan, af);
 					ast_frfree(af);
+					ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 					return &dsp->f;
 				}
 			} else {
@@ -1297,6 +1300,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 							ast_queue_frame(chan, af);
 						ast_frfree(af);
 					}
+					ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 					return &dsp->f;
 				} else {
 					memset(&dsp->f, 0, sizeof(dsp->f));
@@ -1314,6 +1318,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 					if (chan)
 						ast_queue_frame(chan, af);
 					ast_frfree(af);
+					ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 					return &dsp->f;
 				}
 			}
@@ -1331,6 +1336,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 			if (chan)
 				ast_queue_frame(chan, af);
 			ast_frfree(af);
+			ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 			return &dsp->f;
 		}
 	}
@@ -1403,6 +1409,17 @@ void ast_dsp_set_features(struct ast_dsp *dsp, int features)
 
 void ast_dsp_free(struct ast_dsp *dsp)
 {
+	if (ast_test_flag(&dsp->f, AST_FRFLAG_FROM_DSP)) {
+		/* If this flag is still set, that means that the dsp's destruction 
+		 * been torn down, while we still have a frame out there being used.
+		 * When ast_frfree() gets called on that frame, this ast_trans_pvt
+		 * will get destroyed, too. */
+
+		/* Set the magic flag to destroy the dsp when the frame is freed */
+		dsp->freqcount = -1;
+
+		return;
+	}
 	ast_free(dsp);
 }
 
@@ -1516,3 +1533,17 @@ int ast_dsp_get_tcount(struct ast_dsp *dsp)
 {
 	return dsp->tcount;
 }
+
+void ast_dsp_frame_freed(struct ast_frame *fr)
+{
+	struct ast_dsp *dsp;
+
+	ast_clear_flag(fr, AST_FRFLAG_FROM_DSP);
+
+	dsp = (struct ast_dsp *) (((char *) fr) - offsetof(struct ast_dsp, f));
+
+	if (dsp->freqcount != -1)
+		return;
+	
+	ast_dsp_free(dsp);
+}
diff --git a/main/frame.c b/main/frame.c
index 07ce936f2..dc471eebe 100644
--- a/main/frame.c
+++ b/main/frame.c
@@ -37,6 +37,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/threadstorage.h"
 #include "asterisk/linkedlists.h"
 #include "asterisk/translate.h"
+#include "asterisk/dsp.h"
 
 #ifdef TRACE_FRAMES
 static int headers;
@@ -308,6 +309,8 @@ void ast_frame_free(struct ast_frame *fr, int cache)
 {
 	if (ast_test_flag(fr, AST_FRFLAG_FROM_TRANSLATOR))
 		ast_translate_frame_freed(fr);
+	else if (ast_test_flag(fr, AST_FRFLAG_FROM_DSP))
+		ast_dsp_frame_freed(fr);
 
 	if (!fr->mallocd)
 		return;
@@ -357,6 +360,7 @@ struct ast_frame *ast_frisolate(struct ast_frame *fr)
 	void *newdata;
 
 	ast_clear_flag(fr, AST_FRFLAG_FROM_TRANSLATOR);
+	ast_clear_flag(fr, AST_FRFLAG_FROM_DSP);
 
 	if (!(fr->mallocd & AST_MALLOCD_HDR)) {
 		/* Allocate a new header if needed */