[PATCH] Fix nasty /proc vulnerability (CVE-2006-3626)

Fix nasty /proc vulnerability

We have a bad interaction with both the kernel and user space being able
to change some of the /proc file status.  This fixes the most obvious
part of it, but I expect we'll also make it harder for users to modify
even their "own" files in /proc.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 6cc77dc3f3ff79c49fa7d4ce89360b595995d839..5a8b89a8a46730841b2a863b4b43e5ab8f24650b 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1404,6 +1404,7 @@ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
                } else {
                        inode->i_uid = 0;
                        inode->i_gid = 0;
+                       inode->i_mode = 0;
                }
                security_task_to_inode(task, inode);
                return 1;