[lxc-devel] [PATCH] fix wait status in pid reuse case

[Serge Hallyn]

Quoting Dwight Engen (dwight.engen at oracle.com):
> Commit 37c3dfc9 sets the wait status on only the child pid. It
> intended to match the pid only once to protect against pid reuse but it
> won't because the indicator was reset to 0 every time at the top of the
> loop. If the child pid is reused, the wait status will be set again.
> Fix by setting indicator outside the loop.
> 
> Signed-off-by: Dwight Engen <dwight.engen at oracle.com>

Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>

> ---
>  src/lxc/lxc_init.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/src/lxc/lxc_init.c b/src/lxc/lxc_init.c
> index 5693da5..c83c2f1 100644
> --- a/src/lxc/lxc_init.c
> +++ b/src/lxc/lxc_init.c
> @@ -63,7 +63,7 @@ int main(int argc, char *argv[])
>  	int err = -1;
>  	char **aargv;
>  	sigset_t mask, omask;
> -	int i, shutdown = 0;
> +	int i, have_status = 0, shutdown = 0;
>  
>  	while (1) {
>  		int ret = getopt_long_only(argc, argv, "", options, NULL);
> @@ -162,7 +162,6 @@ int main(int argc, char *argv[])
>  	err = 0;
>  	for (;;) {
>  		int status;
> -		int orphan = 0;
>  		pid_t waited_pid;
>  
>  		switch (was_interrupted) {
> @@ -209,10 +208,10 @@ int main(int argc, char *argv[])
>  		 * (not wrapped pid) and continue to wait for
>  		 * the end of the orphan group.
>  		 */
> -		if ((waited_pid != pid) || (orphan ==1))
> -			continue;
> -		orphan = 1;
> -		err = lxc_error_set_and_log(waited_pid, status);
> +		if (waited_pid == pid && !have_status) {
> +			err = lxc_error_set_and_log(waited_pid, status);
> +			have_status = 1;
> +		}
>  	}
>  out:
>  	return err;
> -- 
> 1.7.12.3
> 
> 
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