FreeBSD: Fix leaked strings in libspl mnttab

The FreeBSD implementations of various libspl functions for getting
mounted device information were found to leak several strings which
were being allocated in statfs2mnttab but never freed.

The Solaris getmntany(3C) and related interfaces are expected to return
strings residing in static buffers that need to be copied rather than
freed by the caller.

Use static thread-local storage to stash the mnttab structure strings
from FreeBSD's statfs info rather than strings allocated on the heap by
strdup(3).

While here, remove some stray commented out lines.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #12961
This commit is contained in:
Ryan Moeller 2022-01-14 15:38:32 -05:00 committed by GitHub
parent 12bd322dde
commit 69c5e694a1
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1 changed files with 16 additions and 9 deletions

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@ -91,16 +91,28 @@ optadd(char *mntopts, size_t size, const char *opt)
strlcat(mntopts, opt, size);
}
static __thread char gfstypename[MFSNAMELEN];
static __thread char gmntfromname[MNAMELEN];
static __thread char gmntonname[MNAMELEN];
static __thread char gmntopts[MNTMAXSTR];
void
statfs2mnttab(struct statfs *sfs, struct mnttab *mp)
{
static char mntopts[MNTMAXSTR];
long flags;
mntopts[0] = '\0';
strlcpy(gfstypename, sfs->f_fstypename, sizeof (gfstypename));
mp->mnt_fstype = gfstypename;
strlcpy(gmntfromname, sfs->f_mntfromname, sizeof (gmntfromname));
mp->mnt_special = gmntfromname;
strlcpy(gmntonname, sfs->f_mntonname, sizeof (gmntonname));
mp->mnt_mountp = gmntonname;
flags = sfs->f_flags;
#define OPTADD(opt) optadd(mntopts, sizeof (mntopts), (opt))
gmntopts[0] = '\0';
#define OPTADD(opt) optadd(gmntopts, sizeof (gmntopts), (opt))
if (flags & MNT_RDONLY)
OPTADD(MNTOPT_RO);
else
@ -121,10 +133,7 @@ statfs2mnttab(struct statfs *sfs, struct mnttab *mp)
else
OPTADD(MNTOPT_EXEC);
#undef OPTADD
mp->mnt_special = strdup(sfs->f_mntfromname);
mp->mnt_mountp = strdup(sfs->f_mntonname);
mp->mnt_fstype = strdup(sfs->f_fstypename);
mp->mnt_mntopts = strdup(mntopts);
mp->mnt_mntopts = gmntopts;
}
static struct statfs *gsfs = NULL;
@ -166,7 +175,6 @@ fail:
int
getmntany(FILE *fd __unused, struct mnttab *mgetp, struct mnttab *mrefp)
{
// struct statfs *sfs;
int i, error;
error = statfs_init();
@ -195,7 +203,6 @@ getmntany(FILE *fd __unused, struct mnttab *mgetp, struct mnttab *mrefp)
int
getmntent(FILE *fp, struct mnttab *mp)
{
// struct statfs *sfs;
int error, nfs;
nfs = (int)lseek(fileno(fp), 0, SEEK_CUR);