linux/fs/namei.c
Al Viro 7507c7e113 RCU pathwalk breakage when running into a symlink overmounting something
commit 3cab989afd upstream.

Calling unlazy_walk() in walk_component() and do_last() when we find
a symlink that needs to be followed doesn't acquire a reference to vfsmount.
That's fine when the symlink is on the same vfsmount as the parent directory
(which is almost always the case), but it's not always true - one _can_
manage to bind a symlink on top of something.  And in such cases we end up
with excessive mntput().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06 21:59:20 +02:00

4445 lines
110 KiB