mount: fix mount helper fs option handling

If a mount helper is used, only argopts (given on commandline) are
passed to the helper via -o parameter. Option strings from fstab are
ignored.

This patch replaces global argopts pointer with a character array
fsopts. A maximum length for filesytem options is #defined (used by
fsopts and data), and argument/mntent options are length-checked to fit.
A filesystem with too long an option string will print an error, cause
mount to exit with an error status, and not attempt to mount the
filesystem. This obviates the need for overflow checking of data in
parseopts(), though it hasn't been removed.
This commit is contained in:
Brad Barden 2016-01-28 15:53:36 -06:00 committed by sin
parent 4ece17d605
commit 4dbd00fc94
1 changed files with 21 additions and 11 deletions

32
mount.c
View File

@ -15,6 +15,8 @@
#include "text.h" #include "text.h"
#include "util.h" #include "util.h"
#define FSOPTS_MAXLEN 512
struct { struct {
const char *opt; const char *opt;
const char *notopt; const char *notopt;
@ -37,7 +39,7 @@ struct {
}; };
static unsigned long argflags = 0; static unsigned long argflags = 0;
static char *argopts = NULL; static char fsopts[FSOPTS_MAXLEN] = "";
static char * static char *
findtype(const char *types, const char *t) findtype(const char *types, const char *t)
@ -121,9 +123,9 @@ mounthelper(const char *fsname, const char *dir, const char *fstype)
if (argflags & MS_REC) if (argflags & MS_REC)
eargv[i++] = "-R"; eargv[i++] = "-R";
if (argopts) { if (fsopts[0]) {
eargv[i++] = "-o"; eargv[i++] = "-o";
eargv[i++] = argopts; eargv[i++] = fsopts;
} }
eargv[i++] = fsname; eargv[i++] = fsname;
eargv[i++] = dir; eargv[i++] = dir;
@ -188,11 +190,11 @@ usage(void)
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
char *types = NULL, data[512] = "", *resolvpath = NULL; char *types = NULL, data[FSOPTS_MAXLEN] = "", *resolvpath = NULL;
char *files[] = { "/proc/mounts", "/etc/fstab", NULL }; char *files[] = { "/proc/mounts", "/etc/fstab", NULL };
const char *source, *target; const char *source, *target;
struct mntent *me = NULL; struct mntent *me = NULL;
int aflag = 0, oflag = 0, status = 0, i, r; int aflag = 0, status = 0, i, r;
unsigned long flags = 0; unsigned long flags = 0;
FILE *fp; FILE *fp;
@ -210,9 +212,9 @@ main(int argc, char *argv[])
aflag = 1; aflag = 1;
break; break;
case 'o': case 'o':
oflag = 1; if (strlcat(fsopts, EARGF(usage()), sizeof(fsopts)) >= sizeof(fsopts))
argopts = EARGF(usage()); eprintf("option string too long\n");
parseopts(argopts, &flags, data, sizeof(data)); parseopts(fsopts, &flags, data, sizeof(data));
break; break;
case 't': case 't':
types = EARGF(usage()); types = EARGF(usage());
@ -260,8 +262,10 @@ main(int argc, char *argv[])
target = me->mnt_dir; target = me->mnt_dir;
source = me->mnt_fsname; source = me->mnt_fsname;
} }
if (!oflag) if (!fsopts[0])
parseopts(me->mnt_opts, &flags, data, sizeof(data)); if (strlcat(fsopts, me->mnt_opts, sizeof(fsopts)) >= sizeof(fsopts))
eprintf("%s: option string too long\n", target);
parseopts(fsopts, &flags, data, sizeof(data));
if (!types) if (!types)
types = me->mnt_type; types = me->mnt_type;
goto mountsingle; goto mountsingle;
@ -294,7 +298,13 @@ mountall:
if (hasmntopt(me, MNTOPT_NOAUTO) || mounted(me->mnt_dir)) if (hasmntopt(me, MNTOPT_NOAUTO) || mounted(me->mnt_dir))
continue; continue;
flags = 0; flags = 0;
parseopts(me->mnt_opts, &flags, data, sizeof(data)); fsopts[0] = '\0';
if (strlcat(fsopts, me->mnt_opts, sizeof(fsopts)) >= sizeof(fsopts)) {
weprintf("%s: option string too long\n", me->mnt_dir);
status = 1;
continue;
}
parseopts(fsopts, &flags, data, sizeof(data));
/* if -t types specified: /* if -t types specified:
* if non-match, skip * if non-match, skip
* if match and prefixed with "no", skip */ * if match and prefixed with "no", skip */