[PATCH] register_chrdev_region() don't hand out the LOCAL/EXPERIMENTAL majors

As pointed out in http://bugzilla.kernel.org/show_bug.cgi?id=7922, dynamic
chardev major allocation can hand out majors which LANANA has defined as being
for local/experimental use.

Cc: Torben Mathiasen <device@lanana.org>
Cc: Greg KH <greg@kroah.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tomas Klas <tomas.klas@mepatek.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/char_dev.c b/fs/char_dev.c
index a885f46ca001..e6194e2b9bb9 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -108,6 +108,13 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
         /* temporary */
         if (major == 0) {
                 for (i = ARRAY_SIZE(chrdevs)-1; i > 0; i--) {
+                        /*
+                         * Disallow the LANANA-assigned LOCAL/EXPERIMENTAL
+                         * majors
+                         */
+                        if ((60 <= i && i <= 63) || (120 <= i && i <= 127) ||
+                                        (240 <= i && i <= 254))
+                                continue;
                         if (chrdevs[i] == NULL)
                                 break;
                 }