From owner-freebsd-hackers  Mon Sep 17 14:56: 2 2001
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Date: Mon, 17 Sep 2001 15:31:58 -0700 (PDT)
From: Julian Elischer <julian@elischer.org>
To: Matt Dillon <dillon@earth.backplane.com>
Cc: hackers@FreeBSD.org
Subject: Re: bug in sshd - signal during free()
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signale interrupying 'free' is ok..
Free is not 'signal-safe' so no malloc/free can be done in a signal..
set the malloc config that catches recursive frees&malocs.


On Mon, 17 Sep 2001, Matt Dillon wrote:

>     sshd died on one of our machines today.  The traceback seems to 
>     indicate that a signal is interrupting a free().  I'm going to 
>     play with the code a bit to see if there's an easy fix.
> 
>     This bug can't occur very often... the key regeneration signal
>     has to occur *just* as sshd is trying to free() something.
> 
> 						-Matt
> 
> (gdb) back
> #0  0x28231e34 in kill () from /usr/lib/libc.so.4
> #1  0x2826dd8a in abort () from /usr/lib/libc.so.4
> #2  0x2826c899 in isatty () from /usr/lib/libc.so.4
> #3  0x2826c8cf in isatty () from /usr/lib/libc.so.4
> #4  0x2826d907 in malloc () from /usr/lib/libc.so.4
> #5  0x2826be58 in __smakebuf () from /usr/lib/libc.so.4
> #6  0x2826bdec in __swsetup () from /usr/lib/libc.so.4
> #7  0x282663ef in vfprintf () from /usr/lib/libc.so.4
> #8  0x28266059 in fprintf () from /usr/lib/libc.so.4
> #9  0x2824e0ed in vsyslog () from /usr/lib/libc.so.4
> #10 0x2824e009 in syslog () from /usr/lib/libc.so.4
> #11 0x804feb3 in do_log ()
> #12 0x806ade3 in log ()
> #13 0x804c742 in key_regeneration_alarm ()
> #14 0xbfbfffac in ?? ()
> #15 0x2826da35 in free () from /usr/lib/libc.so.4
> #16 0x805f087 in xfree ()
> #17 0x804d8be in main ()
> #18 0x804c50d in _start ()
> (gdb) 
> 
> 
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