Messages in this thread Patch in this message | | | Date | Mon, 21 Oct 2013 12:37:32 -0400 | From | Dave Jones <> | Subject | Re: [ 05/11] ext4: fix memory leak in xattr |
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On Fri, Oct 18, 2013 at 12:53:34PM -0700, Greg Kroah-Hartman wrote: > 3.4-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Dave Jones <davej@redhat.com> > > commit 6e4ea8e33b2057b85d75175dd89b93f5e26de3bc upstream. > > If we take the 2nd retry path in ext4_expand_extra_isize_ea, we > potentionally return from the function without having freed these > allocations. If we don't do the return, we over-write the previous > allocation pointers, so we leak either way. > > Spotted with Coverity. > > [ Fixed by tytso to set is and bs to NULL after freeing these > pointers, in case in the retry loop we later end up triggering an > error causing a jump to cleanup, at which point we could have a double > free bug. -- Ted ] > > Signed-off-by: Dave Jones <davej@fedoraproject.org> > Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> > Reviewed-by: Eric Sandeen <sandeen@redhat.com> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I'm still waiting to hear if we also need this..
Ted ?
--
If we take the retry path here, we end up potentially overwriting bh, leaving it with an elevated reference count.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 03e9beb..1423c48 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1352,6 +1352,7 @@ retry: new_extra_isize = s_min_extra_isize; kfree(is); is = NULL; kfree(bs); bs = NULL; + brelse(bh); goto retry; } error = -1;
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