From 9bdb5e285872e5287e57cc200a1507f8e7883d35 Mon Sep 17 00:00:00 2001 From: Ryan Moeller Date: Fri, 14 Jan 2022 15:38:32 -0500 Subject: [PATCH] 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 Reviewed-by: Rich Ercolani Signed-off-by: Ryan Moeller Closes #12961 --- lib/libspl/os/freebsd/mnttab.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/lib/libspl/os/freebsd/mnttab.c b/lib/libspl/os/freebsd/mnttab.c index bd3e3e4e3eef..d830257fbd16 100644 --- a/lib/libspl/os/freebsd/mnttab.c +++ b/lib/libspl/os/freebsd/mnttab.c @@ -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 @@ statfs_init(void) 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);