[asterisk-bugs] [JIRA] (ASTERISK-24473) Crash if a PRI DAHDI span is removed in the middle of a call

[Matt Jordan (JIRA)]

    [ https://issues.asterisk.org/jira/browse/ASTERISK-24473?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=223309#comment-223309 ] 

Matt Jordan commented on ASTERISK-24473:
----------------------------------------

So, I'm not surprised about this in the least. We knew when many of these commands were added that running them while an active {{ast_channel}} was going to cause severe problems. Take, for example, {{pri destroy span}}:

{code}
                e->command = "pri destroy span";
                e->usage =
                        "Usage: pri destroy span <span>\n"
                        "       Destorys D-channel of span and its B-channels.\n"
                        "       DON'T USE THIS UNLESS YOU KNOW WHAT YOU ARE DOING.\n";
                return NULL;
{code}

Or {{dahdi destroy channels}}:

{code}
        case CLI_INIT:
                e->command = "dahdi destroy channels";
                e->usage =
                        "Usage: dahdi destroy channels <from_channel> [<to_channel>]\n"
                        "       DON'T USE THIS UNLESS YOU KNOW WHAT YOU ARE DOING.  Immediately removes a given channel, whether it is in use or not\n";
                return NULL;
        case CLI_GENERATE:
                return NULL;
        }
{code}

Those large, all caps messages are there exactly because of this problem. Mucking with the private {{chan_dahdi}} information while an {{ast_channel}} is in use will crash. Asterisk is not designed for this feature.

I'm not saying this can't be fixed: it's software. But I think this warrants some serious consideration, because I don't see any way to fix this without massive overhauls in {{chan_dahdi}}. I think a proposal for how you would like this system to function in {{chan_dahdi}} would be appropriate, and should be started on the {{asterisk-dev}} list.

> Crash if a PRI DAHDI span is removed in the middle of a call
> ------------------------------------------------------------
>
>                 Key: ASTERISK-24473
>                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-24473
>             Project: Asterisk
>          Issue Type: Bug
>      Security Level: None
>          Components: Channels/chan_dahdi
>    Affects Versions: 12.0.0, 13.0.0-beta3
>            Reporter: Tzafrir Cohen
>
> Asterisk now includes support for destroying DAHDI channels and pri spans when the device that includes them disappears (try: 'dahdi_span_assignment remove' , or, well, disconnect an Astribank).
> (On a different note: some work is needed to support mfcr2 and ss7 channels)
> However this fails to work when a channel is part of a span and is in the middle of a call. destroy_channel() is called with now=1.
> One example backtrace:
> {noformat}
> #0  0x0039e560 in pthread_mutex_trylock () from /lib/libpthread.so.0
> #1  0x04fb11b0 in dahdi_read (ast=0xb72d27b4) at chan_dahdi.c:9207
> #2  0x080d0a7b in __ast_read (chan=0xb72d27b4, dropaudio=0) at channel.c:4054
> #3  0x080d5cfb in ast_read (c0=0x90a6cec, c1=0xb72d27b4, config=0xb5ee7104, fo=0xb5ee6b60, rc=0xb5ee6b5c) at channel.c:4408
> #4  ast_generic_bridge (c0=0x90a6cec, c1=0xb72d27b4, config=0xb5ee7104, fo=0xb5ee6b60, rc=0xb5ee6b5c) at channel.c:7630
> #5  ast_channel_bridge (c0=0x90a6cec, c1=0xb72d27b4, config=0xb5ee7104, fo=0xb5ee6b60, rc=0xb5ee6b5c) at channel.c:8105
> #6  0x08114482 in ast_bridge_call (chan=0x90a6cec, peer=0xb72d27b4, config=0xb5ee7104) at features.c:4489
> #7  0x027807ee in dial_exec_full (chan=0x90a6cec, data=<value optimized out>, peerflags=0xb5ee7958, continue_exec=0x0) at app_dial.c:3047
> #8  0x02781bfe in dial_exec (chan=0x90a6cec, data=0xb5ee9cbc "DAHDI/g0/1002,300,Tt") at app_dial.c:3130
> #9  0x081789bd in pbx_exec (c=0x90a6cec, app=0x9060c80, data=0xb5ee9cbc "DAHDI/g0/1002,300,Tt") at pbx.c:1622
> #10 0x08184556 in pbx_extension_helper (c=0x90a6cec, con=0x0, context=0x90a78a0 "macro-dialout-trunk", exten=0x90a78f0 "s", priority=22, label=0x0, 
>     callerid=0xb7201f48 "1001", action=E_SPAWN, found=0xb5eebfb8, combined_find_spawn=1) at pbx.c:4915
> #11 0x00e315ac in _macro_exec (chan=<value optimized out>, data=0x90a78f0 "s", exclusive=0) at app_macro.c:412
> #12 0x081789bd in pbx_exec (c=0x90a6cec, app=0x904edf0, data=0xb5eee9ac "dialout-trunk,1,1002,,off") at pbx.c:1622
> #13 0x08184556 in pbx_extension_helper (c=0x90a6cec, con=0x0, context=0x90a78a0 "macro-dialout-trunk", exten=0x90a78f0 "s", priority=5, label=0x0, 
>     callerid=0xb7201f48 "1001", action=E_SPAWN, found=0xb5ef0ad8, combined_find_spawn=1) at pbx.c:4915
> #14 0x0818c450 in ast_spawn_extension (c=0x90a6cec, args=0x0) at pbx.c:6037
> #15 __ast_pbx_run (c=0x90a6cec, args=0x0) at pbx.c:6512
> #16 0x0818e039 in ast_pbx_run_args (c=0x90a6cec) at pbx.c:6890
> #17 ast_pbx_run (c=0x90a6cec) at pbx.c:6899
> #18 0x04fbd5a9 in __analog_ss_thread (data=0xb728d268) at sig_analog.c:2164
> #19 0x081d71f7 in dummy_start (data=0x8cd8cb0) at utils.c:1192
> #20 0x0039cb39 in start_thread () from /lib/libpthread.so.0
> #21 0x002d8ace in error_at_line () from /lib/libc.so.6
> Backtrace stopped: previous frame inner to this frame (corrupt stack?)
> {noformat}
> and in frame 1: we get that:
> p = ast_channel_tech_pvt(ast);
> p is NULL



--
This message was sent by Atlassian JIRA
(v6.2#6252)