[Pkg-shadow-devel] Bug#476519: Bug#476519: shell-mode garbles input

Stephane Chazelas Stephane_Chazelas at yahoo.fr
Fri May 2 15:50:53 UTC 2008


On Fri, May 02, 2008 at 11:27:00PM +0800, jidanni at jidanni.org wrote:
> SC> Try
> SC> sudo env -i SHELLOPTS=xtrace su -p - nobody
> (I don't use sudo)
> uid=0(root) gid=0(root) groups=0(root)
> # env -i SHELLOPTS=xtrace su -p - nobody
> + PATH=/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
> + '[' /bin/sh ']'
> + PS1='\u@\h:\w\$ '
> + export PATH
> + umask 022
> nobody at jidanni2:/root$ kill -1 $$
> + kill -1 6215
> # env -i SHELLOPTS=xtrace su -p - nobody
> + PATH=/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
> + '[' /bin/sh ']'
> + PS1='\u@\h:\w\$ '
> + export PATH
> + umask 022
> nobody at jidanni2:/root$ logout
> #
> 
> Above on my first attempt the shell stayed alive, so I typed kill -1
> $$ (instead of exit, so it would be clear that I typed it, as that is
> something the "magic hand" never uses.) On the second and later
> attempts, some magic hand typed "logout" for me. The magic hand also
> sometimes types "exit"...
[...]

Does that happen straight away or after a delay?

The "logout" thing looks a bit like eof from the terminal.

It could be the "read" being interupted by a signal or something
like that.

strace would probably help then:

sudo env -i strace -vfo /tmp/strace.out /bin/su - nobody

And look at the last read(0 in /tmp/strace.out

It could be worth checking the ulimits as well.

-- 
Stéphane





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