[PATCH] smbfs chroot issue (CVE-2006-1864)

Mark Moseley reported that a chroot environment on a SMB share can be left
via "cd ..\\".  Similar to CVE-2006-1863 issue with cifs, this fix is for
smbfs.

Steven French <sfrench@us.ibm.com> wrote:

Looks fine to me.  This should catch the slash on lookup or equivalent,
which will be all obvious paths of interest.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/smbfs/dir.c b/fs/smbfs/dir.c
index 34c7a11d91f0..70d9c5a37f5a 100644
--- a/fs/smbfs/dir.c
+++ b/fs/smbfs/dir.c
@@ -434,6 +434,11 @@ smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
         if (dentry->d_name.len > SMB_MAXNAMELEN)
                 goto out;
 
+        /* Do not allow lookup of names with backslashes in */
+        error = -EINVAL;
+        if (memchr(dentry->d_name.name, '\\', dentry->d_name.len))
+                goto out;
+
         lock_kernel();
         error = smb_proc_getattr(dentry, &finfo);
 #ifdef SMBFS_PARANOIA