Re: sshd fork failure

[marco atzeri <marco.atzeri@gmail.com>]

On 10/13/2012 6:54 PM, Christopher Faylor wrote:
> On Sat, Oct 13, 2012 at 06:10:23PM +0200, marco atzeri wrote:
>> On 10/13/2012 5:39 PM, Christopher Faylor wrote:
>>> On Thu, Aug 30, 2012 at 06:44:39PM +0200, marco atzeri wrote:
>>>> Hi,
>>>> tracing the sshd process on latest cygwin shapshot ,
>>>> I see that the fork is failing due to exception C0000005
>>>>
>>>>       1       1 [main] sshd (4644)
>>>> **********************************************
>>>>    5921    5922 [main] sshd (4644) Program name:
>>>> E:\cygwin\usr\sbin\sshd.exe (windows pid 4644)
>>>>      30    5952 [main] sshd (4644) OS version:   Windows NT-6.1
>>>>      25    5977 [main] sshd (4644)
>>>> **********************************************
>>>>     636    6613 [main] sshd (4644) sigprocmask: 0 = sigprocmask (0,
>>>> 0x6123D428, 0x610FBB30)
>>>>     122    6735 [main] sshd 4644 child_copy: cygheap - hp 0x20C low
>>>> 0x612708D0, high 0x61277640, res 1
>>>>    1368    8103 [main] sshd 4644 child_copy: done
>>>> --- Process 4644, exception C0000005 at 61137277
>>>>
>>>>
>>>>
>>>> $ addr2line.exe 61137277 -e /usr/bin/cygwin1.dll
>>>> /netrel/src/cygwin-snapshot-20120827-1/newlib/libc/stdlib/mbtowc_r.c:323
>>>>
>>>> that should be:
>>>>
>>>>    ch = (state->__count == 1) ? t[i++] : state->__value.__wchb[1];
>>>>
>>>> inside __utf8_mbtowc .
>>>> It looks a strange place for a fork failure, but it is used in
>>>> winsup/cygwin/cygheap.cc so it could make sense.
>>>>
>>>> Any suggestion how to follow/debug the child portion of fork ?
>>>
>>> Is this still failing?  We're looking to release 1.7.17 soon.
>>
>> on  20121012 similar but in another location.
>>
>> --- Process 6280, exception C0000005 at 61137DC8
>>    427  147466 [main] sshd 6280 exception::handle: In
>> cygwin_except_handler exception 0xC0000005 at 0x61137DC8 sp 0x289270
>>     67  147533 [main] sshd 6280 exception::handle: In
>> cygwin_except_handler signal 11 at 0x61137DC8
>>     38  147571 [main] sshd 6280 exception::handle: In
>> cygwin_except_handler calling 0x0
>>     37  147608 [main] sshd 6280 exception::handle: Exception:
>> STATUS_ACCESS_VIOLATION
>>
>>   addr2line.exe 61137DC8 -e /usr/bin/cygwin1.dll
>> /netrel/src/cygwin-snapshot-20121012-1/newlib/libc/stdio/findfp.c:296
>
> You seem to be the only person reporting this problem.  Everyone else
> updates to a snapshot to cure ssh problems.  FWIW, that instruction
> shouldn't even be executed.
>
> cgf
>

I have such issue only on sshd forking and for long time,
so it is not relative to last snapshots.

As this the is only program that involve several USER accounts
I suspect some crippling "corporate" group policy or a very
strange BLODA effect.

Marco



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