[PATCH] permission checks for chdir need special treatment only on the last step
... so we ought to pass MAY_CHDIR to vfs_permission() instead of having
it triggered on every step of preceding pathname resolution. LOOKUP_CHDIR
is killed by that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index ae0e56f..6c76e1e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -268,8 +268,6 @@
if (nd) {
if (nd->flags & LOOKUP_ACCESS)
extra |= MAY_ACCESS;
- if (nd->flags & LOOKUP_CHDIR)
- extra |= MAY_CHDIR;
if (nd->flags & LOOKUP_OPEN)
extra |= MAY_OPEN;
}
diff --git a/fs/open.c b/fs/open.c
index b2e4c93..8e02d42 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -501,12 +501,11 @@
struct nameidata nd;
int error;
- error = __user_walk(filename,
- LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
+ error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd);
if (error)
goto out;
- error = vfs_permission(&nd, MAY_EXEC);
+ error = vfs_permission(&nd, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 24d88e9..3cf62d2 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -55,7 +55,6 @@
#define LOOKUP_OPEN (0x0100)
#define LOOKUP_CREATE (0x0200)
#define LOOKUP_ACCESS (0x0400)
-#define LOOKUP_CHDIR (0x0800)
extern int __user_walk(const char __user *, unsigned, struct nameidata *);
extern int __user_walk_fd(int dfd, const char __user *, unsigned, struct nameidata *);
