Date: Sun, 28 Jun 2020 18:49:36 -0600 From: Alan Somers <asomers@freebsd.org> To: Warner Losh <imp@bsdimp.com> Cc: Mark Johnston <markj@freebsd.org>, src-committers <src-committers@freebsd.org>, svn-src-all <svn-src-all@freebsd.org>, svn-src-head <svn-src-head@freebsd.org> Subject: Re: svn commit: r342699 - head/sbin/savecore Message-ID: <CAOtMX2jniaDDoCFDyXqjuC6apD660_Qxu6MXUQ%2BqM3txYy9%2B6g@mail.gmail.com> In-Reply-To: <CANCZdfqtuN2rhkukZXu3k6kV4n1jN-iDME-iHgE55eL82tLQqw@mail.gmail.com> References: <201901021709.x02H9ZPM004185@repo.freebsd.org> <CAOtMX2jJfCdiVAuVPL_9QmUR3EhwjC-DpAk5r=J2=tK9WQKh6w@mail.gmail.com> <CANCZdfqtuN2rhkukZXu3k6kV4n1jN-iDME-iHgE55eL82tLQqw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Jun 28, 2020 at 6:46 PM Warner Losh <imp@bsdimp.com> wrote: > > > On Sun, Jun 28, 2020, 6:41 PM Alan Somers <asomers@freebsd.org> wrote: > >> On Wed, Jan 2, 2019 at 10:09 AM Mark Johnston <markj@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? >> > > So the other spots adjusted large, but this one sets one of its elements. > Help me understand how that is a leak? I'm sure I'm just confused. > Because strdup itself allocates new memory. strdup's return value is always supposed to be freed. -Alan
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOtMX2jniaDDoCFDyXqjuC6apD660_Qxu6MXUQ%2BqM3txYy9%2B6g>