config: Fix parsing of mount options

When parsing mount options e.g. from lxc.mount.entry the specified
options are mapped to the flags constants. To do so, the strings
are compared to the options contained in mount_opt. However,
when comparing the strings, the length of the string is not
checked. That entails that the option "rootcontext=selinux-context"
is mapped to the mount option read-only (ro). This commit fixes
this issue by checking if a '=' is contained in the specified option
and additionally comparing the length of the strings.

Signed-off-by: Maximilian Blenk <Maximilian.Blenk@bmw.de>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index b192c7550ac88b0d9c16918c877de8271559ddda..9410d4c9d8f5bb336d61d148d93c39859a763a8f 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -1853,16 +1853,21 @@ static void parse_mntopt(char *opt, unsigned long *flags, char **data, size_t si
 {
        struct mount_opt *mo;
 
-       /* If opt is found in mount_opt, set or clear flags.
-        * Otherwise append it to data. */
-
-       for (mo = &mount_opt[0]; mo->name != NULL; mo++) {
-               if (strncmp(opt, mo->name, strlen(mo->name)) == 0) {
-                       if (mo->clear)
-                               *flags &= ~mo->flag;
-                       else
-                               *flags |= mo->flag;
-                       return;
+       /* If '=' is contained in opt, the option must go into data. */
+       if (!strchr(opt, '=')) {
+
+               /* If opt is found in mount_opt, set or clear flags.
+                * Otherwise append it to data. */
+               size_t opt_len = strlen(opt);
+               for (mo = &mount_opt[0]; mo->name != NULL; mo++) {
+                       size_t mo_name_len = strlen(mo->name);
+                       if (opt_len == mo_name_len && strncmp(opt, mo->name, mo_name_len) == 0) {
+                               if (mo->clear)
+                                       *flags &= ~mo->flag;
+                               else
+                                       *flags |= mo->flag;
+                               return;
+                       }
                }
        }