Re: XTerm 4.0.1b(144) segfault with ssh -v and sudo
On Thu, Sep 07, 2000 at 08:25:39PM +0300, Tommi Virtanen wrote:
> I can make xterm segfault reproducibly
> on Debian GNU/Linux woody (unstable).
I stumbled over one cause today (it's dependent on the keystrokes, and just
doesn't break on this host ;-). A couple of places in the code I integrated in
#140 aren't checked if the terminal is running in UTF-8 mode before going off
and doing things. Your traceback is one of the two. (I'll put together a
short patch tonight - #146).
> [tv@hq ~/tmp/x]$ ./xterm -version
> XFree86 4.0.1b(144)
>
> If I start an xterm, ssh -v remotehost,
> and run sudo there, so that sudo prompts
> for a password, the local xterm segfaults.
> This only happens with ssh -v, which is
> weird, and needs a specific version of
> _something_ in the remote end -- a bit
> under-updated Debian 2.2 (potato) seems
> to cause it, the newer unstable woody
> doesn't.
>
> crashes:
> sudo 1.6.2p2
> OpenSSH 1.2.3
>
> doesn't crash:
> sudo 1.6.3p5
> OpenSSH 2.1.1p4
>
> Here's the end of strace
>
> select(4, [3], [], [], {0, 0}) = 0 (Timeout)
> read(4, "Password:\0", 4096) = 10
> --- SIGSEGV (Segmentation fault) ---
>
> And ltrace:
>
> memcpy(0x40302548, "Password:", 9) = 0x40302548
> memset(0x40302598, '\200', 9) = 0x40302598
> memset(0x403025e8, '\000', 9) = 0x403025e8
> memset(0x40302638, '\000', 9) = 0x40302638
> --- SIGSEGV (Segmentation fault) ---
>
> Here's a backtrace:
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x8066076 in addXtermCombining ()
> (gdb) bt
> #0 0x8066076 in addXtermCombining ()
> #1 0x804fa3d in VTparse ()
> #2 0x8053b5e in VTRun ()
> #3 0x80697d8 in main ()
> #4 0x40225a52 in __libc_start_main () from /lib/libc.so.6
> (gdb)
>
> Do tell if I can help you any more. I speak
> C well enough and can manage my way with the
> debugger.
>
> --
> tv@{{hq.yok.utu,havoc,gaeshido}.fi,{debian,wanderer}.org,stonesoft.com}
> unix, linux, debian, networks, security, | Error messages
> kernel, TCP/IP, C, perl, free software, | cannot completely convey.
> mail, www, sw devel, unix admin, hacks. | We now know shared loss.
--
Thomas E. Dickey <dickey@herndon4.his.com>
http://dickey.his.com
ftp://dickey.his.com
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