libmount: ignore name=value if only 'name' is expected

For example

	mount /srv/www /mnt -o rw,group=woven,dev,suid

the group= should not be interpreted as userspace mount option, because
umount(8) expects 'group' (without =<value>).

Reported-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libmount/src/optstr.c b/libmount/src/optstr.c
index d0072447be30c7e11b940fab52231c4ce04e6489..1bc2566c42f5c924658de14f0c46c6d2de8fb02c 100644 (file)
--- a/libmount/src/optstr.c
+++ b/libmount/src/optstr.c
@@ -35,6 +35,9 @@ struct libmnt_optloc {
 
 #define mnt_init_optloc(_ol)   (memset((_ol), 0, sizeof(struct libmnt_optloc)))
 
+#define mnt_optmap_entry_novalue(e) \
+               (e && (e)->name && !strchr((e)->name, '=') && !((e)->mask & MNT_PREFIX))
+
 /*
  * Parses the first option from @optstr. The @optstr pointer is set to begin of
  * the next option.
@@ -526,6 +529,10 @@ int mnt_split_optstr(const char *optstr, char **user, char **vfs,
                if (ent && !ent->id)
                        continue;       /* ignore undefined options (comments) */
 
+               /* ignore name=<value> if options map expects <name> only */
+               if (valsz && mnt_optmap_entry_novalue(ent))
+                       m = NULL;
+
                if (ent && m && m == maps[0] && vfs) {
                        if (ignore_vfs && (ent->mask & ignore_vfs))
                                continue;
@@ -595,6 +602,11 @@ int mnt_optstr_get_options(const char *optstr, char **subset,
 
                if (ignore && (ent->mask & ignore))
                        continue;
+
+               /* ignore name=<value> if options map expects <name> only */
+               if (valsz && mnt_optmap_entry_novalue(ent))
+                       continue;
+
                rc = __mnt_optstr_append_option(subset, name, namesz, val, valsz);
                if (rc) {
                        free(*subset);
@@ -655,6 +667,10 @@ int mnt_optstr_get_flags(const char *optstr, unsigned long *flags,
                if (!m || !ent || !ent->id)
                        continue;
 
+               /* ignore name=<value> if options map expects <name> only */
+               if (valsz && mnt_optmap_entry_novalue(ent))
+                       continue;
+
                if (m == map) {                         /* requested map */
                        if (ent->mask & MNT_INVERT)
                                *flags &= ~ent->id;
@@ -748,8 +764,12 @@ int mnt_optstr_apply_flags(char **optstr, unsigned long flags,
                                /*
                                 * remove unwanted option (rw/ro is already set)
                                 */
-                               if (!ent->id)
+                               if (!ent || !ent->id)
                                        continue;
+                               /* ignore name=<value> if options map expects <name> only */
+                               if (valsz && mnt_optmap_entry_novalue(ent))
+                                       continue;
+
                                if (ent->id == MS_RDONLY ||
                                    (ent->mask & MNT_INVERT) ||
                                    (fl & ent->id) != (unsigned long) ent->id) {