On Sun, Jul 25, 2010 at 01:48:16PM +0200, Jilles Tjoelker wrote:
> On Sun, Jul 18, 2010 at 12:20:33PM +1000, Sean wrote:
> > I'm getting the same thing; what shell are you using? I changed my shell 
> > on one machine from /bin/tcsh to /usr/local/bin/bash and problem 
> > disappeared.
> That this workaround helps confirms that masked/ignored SIGPIPE is the
> problem. From a few shells I have tried, bash and zsh reset SIGPIPE to
> caught or default even if it was ignored (only in interactive mode,
> however), while tcsh, sh, mksh and ksh93 leave it ignored.
> The underlying problem is the program that is passing the ignored/masked
> signal to child processes. Please check if the problem occurs with
> various ways to log in (text console, ssh, xterm, etc). Things like PAM
> modules may also cause problems here.
> For example, sshd sets SIGPIPE to ignored, but resets it back to default
> before starting a child process, so assuming I read the code correctly
> it does not cause problems.


pooma% cat
In the other shell,
pooma% ps auxww | grep cat
kostik     41346  0.0  0.0  5824  1084   2  I+   11:34PM   0:00.00 cat
pooma% procstat -i 41346 | grep PIPE
41346 cat              PIPE     ---

pooma% sudo cat
pooma% ps auxww | grep cat
root       41360  0.0  0.0  5824  1084   2  S+   11:36PM   0:00.01 cat
pooma% procstat -i 41366 | grep PIPE
41366 cat              PIPE     ---

And now
oma% sudo -k cat                                                            ~
pooma% ps auxww | grep cat
root       41387  0.0  0.0  5824  1084   2  S+   11:39PM   0:00.01 cat
pooma% procstat -i 41387 | grep PIPE
41387 cat              PIPE     -I-

This would describe both the observed behaviour and the reason why
I was unable to repeat it after the first run.

sudo changelog has a promising entry from 2010-06-09, but I definitely
not going to read sudo code. security/sudo maintainer Cc:ed.

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