svn commit: r342699 - head/sbin/savecore

[Alan Somers]

On Wed, Jan 2, 2019 at 10:09 AM Mark Johnston <markj at freebsd.org> wrote:

> Author: markj
> Date: Wed Jan  2 17:09:35 2019
> New Revision: 342699
> URL: https://svnweb.freebsd.org/changeset/base/342699
>
> Log:
>   Capsicumize savecore(8).
>
>   - Use cap_fileargs(3) to open dump devices after entering capability
>     mode, and use cap_syslog(3) to log messages.
>   - Use a relative directory fd to open output files.
>   - Use zdopen(3) to compress kernel dumps in capability mode.
>
>   Reviewed by:  cem, oshogbo
>   MFC after:    2 months
>   Sponsored by: The FreeBSD Foundation
>   Differential Revision:        https://reviews.freebsd.org/D18458
>
> Modified:
>   head/sbin/savecore/Makefile
>   head/sbin/savecore/savecore.c
>
> Modified: head/sbin/savecore/savecore.c
>
> ==============================================================================
> --- head/sbin/savecore/savecore.c       Wed Jan  2 16:42:07 2019
> (r342698)
> +++ head/sbin/savecore/savecore.c       Wed Jan  2 17:09:35 2019
> (r342699)
>
> +static char **
> +enum_dumpdevs(int *argcp)
> +{
> +       struct fstab *fsp;
> +       char **argv;
> +       int argc, n;
> +
> +       /*
> +        * We cannot use getfsent(3) in capability mode, so we must
> +        * scan /etc/fstab and build up a list of candidate devices
> +        * before proceeding.
> +        */
> +       argc = 0;
> +       n = 8;
> +       argv = malloc(n * sizeof(*argv));
>

It looks like the memory allocated here


> +       if (argv == NULL) {
> +               logmsg(LOG_ERR, "malloc(): %m");
> +               exit(1);
> +       }
> +       for (;;) {
> +               fsp = getfsent();
> +               if (fsp == NULL)
> +                       break;
> +               if (strcmp(fsp->fs_vfstype, "swap") != 0 &&
> +                   strcmp(fsp->fs_vfstype, "dump") != 0)
> +                       continue;
> +               if (argc >= n) {
> +                       n *= 2;
> +                       argv = realloc(argv, n * sizeof(*argv));
>

and here


> +                       if (argv == NULL) {
> +                               logmsg(LOG_ERR, "realloc(): %m");
> +                               exit(1);
> +                       }
> +               }
> +               argv[argc] = strdup(fsp->fs_spec);
>

and here is leaked.  I can't find any corresponding free.  However, neither
Valgrind nor Coverity complains.  What am I missing?  Does this memory
sneakily get freed by a subroutine somewhere, or does Capsicum confuse our
tools?
-Alan