lkml.org 
[lkml]   [2002]   [Dec]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2.4] Fix d_path() truncating excessive long path name vulnerability
Date
Hi Marcelo,

there isn't fixed the d_path() long name truncation vulnerability
(see http://cert.uni-stuttgart.de/archive/bugtraq/2002/03/msg00384.html) in
2.4.x up to 2.4.21-BK.

This trivial patch fixes it. Instead of truncating the path with no error,
caller gets ENAMETOOLONG.

Patch credits go to Jirka Kosina.

Has been in WOLK and in -aa kernels for ages.

ciao, Marc--- linux/fs/dcache.c.orig Mon Feb 25 20:38:08 2002
+++ linux/fs/dcache.c Mon Apr 1 04:16:45 2002
@@ -976,14 +976,17 @@
parent = dentry->d_parent;
namelen = dentry->d_name.len;
buflen -= namelen + 1;
- if (buflen < 0)
- break;
+ if (buflen < 0){
+ retval = ERR_PTR(-ENAMETOOLONG);
+ goto out;
+ }
end -= namelen;
memcpy(end, dentry->d_name.name, namelen);
*--end = '/';
retval = end;
dentry = parent;
}
+out:
return retval;
global_root:
namelen = dentry->d_name.len;
@@ -992,6 +995,8 @@
retval -= namelen-1; /* hit the slash */
memcpy(retval, dentry->d_name.name, namelen);
}
+ else
+ retval = ERR_PTR(-ENAMETOOLONG);
return retval;
}

@@ -1041,8 +1046,11 @@
spin_unlock(&dcache_lock);

error = -ERANGE;
+
+ if (cwd == ERR_PTR(-ENAMETOOLONG)) error = -ENAMETOOLONG;
+
len = PAGE_SIZE + page - cwd;
- if (len <= size) {
+ if (len <= size && error != -ENAMETOOLONG) {
error = len;
if (copy_to_user(buf, cwd, len))
error = -EFAULT;
\
 
 \ /
  Last update: 2005-03-22 13:31    [W:0.030 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site