Re: 2.6.22-rc6(mm1) Unable to handle kernel NULL pointer dereference - git-bisect result

[Markus Trippelsdorf <markus@trippelsdorf.de>]

On Sun, Jul 08, 2007 at 10:06:43AM -0700, Ulrich Drepper wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Markus Trippelsdorf wrote:
> > I tested this further and it turned out that the Linus tree is also
> > affected. So I ran git-bisect, after I found out that version
> > 2.6.21.6 was not affected by this bug.
> 
> Try this patch.  The vfs_permission test can be skipped since the VFS
> isn't involved.  We got the inode etc from a file descriptor.
> 
> 
> Signed-Off-By: Ulrich Drepper <drepper@redhat.com>
> 
> diff --git a/fs/utimes.c b/fs/utimes.c
> index 480f7c8..873edcb 100644
> - --- a/fs/utimes.c
> +++ b/fs/utimes.c
> @@ -106,7 +106,8 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags
>                  if (IS_IMMUTABLE(inode))
>                          goto dput_and_out;
> 
> - -               if (current->fsuid != inode->i_uid &&
> +               if (f == NULL &&
> +                   current->fsuid != inode->i_uid &&
>                     (error = vfs_permission(&nd, MAY_WRITE)) != 0)
>                         goto dput_and_out;
>         }
> 
> 

I had to hand apply the patch, but it solved the problem.
Thanks.
-- 
Markus
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