From e409a129af8da2d68d2a51c2b8131405b99cb01d Mon Sep 17 00:00:00 2001
From: Mark Michelson <mmichelson@digium.com>
Date: Fri, 11 Apr 2008 15:49:35 +0000
Subject: [PATCH] Merged revisions 114063 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4
........
r114063 | mmichelson | 2008-04-11 10:44:28 -0500 (Fri, 11 Apr 2008) | 11 lines
Fix a race condition that may happen between a sip hangup
and a "core show channel" command. This patch adds locking
to prevent the resulting crash.
(closes issue #12155)
Reported by: tsearle
Patches:
show_channels_crash2.patch uploaded by tsearle (license 373)
Tested by: tsearle
........
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@114064 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
main/features.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/main/features.c b/main/features.c
index 99bf768066..089f27a0fe 100644
--- a/main/features.c
+++ b/main/features.c
@@ -2098,6 +2098,7 @@ int ast_bridge_call(struct ast_channel *chan,struct ast_channel *peer,struct ast
bridge_cdr = ast_cdr_alloc();
if (bridge_cdr) {
if (chan->cdr && peer->cdr) { /* both of them? merge */
+ ast_channel_lock(chan); /* lock the channel before modifying cdrs */
ast_cdr_init(bridge_cdr,chan); /* seems more logicaller to use the destination as a base, but, really, it's random */
ast_cdr_start(bridge_cdr); /* now is the time to start */
@@ -2106,14 +2107,22 @@ int ast_bridge_call(struct ast_channel *chan,struct ast_channel *peer,struct ast
if (!ast_test_flag(chan->cdr, AST_CDR_FLAG_LOCKED))
ast_cdr_discard(chan->cdr); /* if locked cdrs are in chan, they are taken over in the merge */
+ chan->cdr = NULL;
+ ast_channel_unlock(chan);
/* absorb the peer cdr */
+ ast_channel_lock(peer);
ast_cdr_merge(bridge_cdr, peer->cdr);
if (!ast_test_flag(peer->cdr, AST_CDR_FLAG_LOCKED))
ast_cdr_discard(peer->cdr); /* if locked cdrs are in peer, they are taken over in the merge */
- peer->cdr = NULL;
+ peer->cdr = NULL; /* remove pointer to freed memory before releasing the lock */
+ ast_channel_unlock(peer);
+
+ ast_channel_lock(chan);
chan->cdr = bridge_cdr; /* make this available to the rest of the world via the chan while the call is in progress */
+ ast_channel_unlock(chan);
} else if (chan->cdr) {
+ ast_channel_lock(chan); /* Lock before modifying CDR */
/* take the cdr from the channel - literally */
ast_cdr_init(bridge_cdr,chan);
/* absorb this data */
@@ -2121,7 +2130,9 @@ int ast_bridge_call(struct ast_channel *chan,struct ast_channel *peer,struct ast
if (!ast_test_flag(chan->cdr, AST_CDR_FLAG_LOCKED))
ast_cdr_discard(chan->cdr); /* if locked cdrs are in chan, they are taken over in the merge */
chan->cdr = bridge_cdr; /* make this available to the rest of the world via the chan while the call is in progress */
+ ast_channel_unlock(chan);
} else if (peer->cdr) {
+ ast_channel_lock(peer); /* Lock before modifying CDR */
/* take the cdr from the peer - literally */
ast_cdr_init(bridge_cdr,peer);
/* absorb this data */
@@ -2130,10 +2141,13 @@ int ast_bridge_call(struct ast_channel *chan,struct ast_channel *peer,struct ast
ast_cdr_discard(peer->cdr); /* if locked cdrs are in chan, they are taken over in the merge */
peer->cdr = NULL;
peer->cdr = bridge_cdr; /* make this available to the rest of the world via the chan while the call is in progress */
+ ast_channel_unlock(peer);
} else {
+ ast_channel_lock(chan); /* Lock before modifying CDR */
/* make up a new cdr */
ast_cdr_init(bridge_cdr,chan); /* eh, just pick one of them */
chan->cdr = bridge_cdr; /* */
+ ast_channel_unlock(chan);
}
if (ast_strlen_zero(bridge_cdr->dstchannel)) {
if (strcmp(bridge_cdr->channel, peer->name) != 0)
--
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