[asterisk-bugs] [JIRA] (ASTERISK-25212) Segfault when triggering deadlock detection

[Rusty Newton (JIRA)]

     [ https://issues.asterisk.org/jira/browse/ASTERISK-25212?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Rusty Newton updated ASTERISK-25212:
------------------------------------

    Component/s: Core/General

> Segfault when triggering deadlock detection
> -------------------------------------------
>
>                 Key: ASTERISK-25212
>                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-25212
>             Project: Asterisk
>          Issue Type: Bug
>      Security Level: None
>          Components: Core/General
>    Affects Versions: 11.19.0
>            Reporter: Walter Doekes
>         Attachments: btallfull.txt, btall.txt, btfull.txt, bt.txt, infothreads.txt
>
>
> When attempting to reproduce a deadlock, I enabled DEBUG_THREADS and DETECT_DEADLOCKS.
> Instead of detecting the deadlock, sometimes Asterisk crashes instead.
> Recent crash contains this:
> {noformat}
> (gdb) bt
> #0  pthread_cond_signal@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S:69
> #1  0x0000000000509909 in __ast_cond_signal (filename=0x5c993b "autoservice.c", lineno=222, func=0x5c9a10 <__PRETTY_FUNCTION__.13263> "ast_autoservice_start", cond_name=0x5c9967 "&as_cond", 
>     cond=0x885680 <as_cond>) at lock.c:508
> #2  0x0000000000456ec8 in ast_autoservice_start (chan=0x3b31188) at autoservice.c:222
> #3  0x00000000004573ba in ast_autoservice_chan_hangup_peer (chan=0x3b31188, peer=0x7eff1038ef68) at autoservice.c:317
> #4  0x00007efed32345c7 in dial_exec_full (chan=0x3b31188, data=0x7efec6cc6b10 "SIP/bob", peerflags=0x7efec6cc64c0, continue_exec=0x0) at app_dial.c:3078
> #5  0x00007efed323499a in dial_exec (chan=0x3b31188, data=0x7efec6cc6b10 "SIP/bob") at app_dial.c:3130
> #6  0x0000000000533b49 in pbx_exec (c=0x3b31188, app=0x27c0440, data=0x7efec6cc6b10 "SIP/bob") at pbx.c:1677
> #7  0x000000000053e7c8 in pbx_extension_helper (c=0x3b31188, con=0x0, context=0x3b31fd8 "default", exten=0x3b32028 "bob", priority=1, label=0x0, callerid=0x3df43b0 "alice", action=E_SPAWN, 
>     found=0x7efec6ccabfc, combined_find_spawn=1) at pbx.c:4970
> {noformat}
> {noformat}
> (gdb) disass
> Dump of assembler code for function pthread_cond_signal@@GLIBC_2.3.2:
> ...
>    0x00007eff16ab3c4e <+62>:	je     0x7eff16ab3c67 <pthread_cond_signal@@GLIBC_2.3.2+87>
>    0x00007eff16ab3c50 <+64>:	mov    0x20(%r8),%rcx
> => 0x00007eff16ab3c54 <+68>:	mov    0x10(%rcx),%r11d
>    0x00007eff16ab3c58 <+72>:	and    $0x30,%r11d
>    0x00007eff16ab3c5c <+76>:	cmp    $0x20,%r11d
> ...
> (gdb) up
> #1  0x0000000000509909 in __ast_cond_signal (filename=0x5c993b "autoservice.c", lineno=222, func=0x5c9a10 <__PRETTY_FUNCTION__.13263> "ast_autoservice_start", cond_name=0x5c9967 "&as_cond", 
>     cond=0x885680 <as_cond>) at lock.c:508
> 508		return pthread_cond_signal(cond);
> (gdb) print cond
> $55 = (ast_cond_t *) 0x885680 <as_cond>
> (gdb) print *cond
> $56 = {__data = {__lock = 1, __futex = 1638, __total_seq = 8389759012580623496, __wakeup_seq = 7809628147932885606, __woken_seq = 6874024004411486821, __mutex = 0x7069700074696e69, __nwaiters = 101, 
>     __broadcast_seq = 2063597568}, __size = "\001\000\000\000f\006\000\000\210\004\000\000_intfrnal_alertpipe_init\000pipe\000\000\000\000\000\000{", __align = 7035156430849}
> (gdb) p *(char(*)[48])cond
> $57 = "\001\000\000\000f\006\000\000\210\004\000\000_intfrnal_alertpipe_init\000pipe\000\000\000\000\000\000{"
> {noformat}
> That doesn't look like valid values in the cond struct.
> {noformat}
> (gdb) info registers
> rax            0xca	202
> rbx            0x10	16
> rcx            0x7069700074696e69	8100128552057925225
> rdx            0x1	1
> rsi            0x5	5
> rdi            0x885684	8935044
> rbp            0x7efec6cc5520	0x7efec6cc5520
> rsp            0x7efec6cc54f0	0x7efec6cc54f0
> r8             0x885680	8935040
> r9             0x843510	8664336
> r10            0x7efec4456de0	139632679677408
> r11            0x7efec6ccafc8	139632722096072
> r12            0x3b32028	62070824
> r13            0x1	1
> r14            0x3caa942	63613250
> r15            0x27c04a0	41682080
> rip            0x509909	0x509909 <__ast_cond_signal+39>
> eflags         0x10217	[ CF PF AF IF RF ]
> cs             0x33	51
> ss             0x2b	43
> ds             0x0	0
> es             0x0	0
> fs             0x0	0
> gs             0x0	0
> {noformat}
> Cheers,
> Walter Doekes
> OSSO B.V.



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