Re: [PATCH 4.4.y] tcp: Fix missing range_truesize enlargement in the backport

[Greg Kroah-Hartman]

On Wed, Aug 15, 2018 at 11:58:46AM +0200, Takashi Iwai wrote:
> The 4.4.y stable backport dc6ae4dffd65 for the upstream commit
> 3d4bf93ac120 ("tcp: detect malicious patterns in
> tcp_collapse_ofo_queue()") missed a line that enlarges the
> range_truesize value, which broke the whole check.
> 
> Fixes: dc6ae4dffd65 ("tcp: detect malicious patterns in tcp_collapse_ofo_queue()")
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
> ---
> 
> Greg, this is a fix-up specific to 4.4.y stable backport that had a
> slightly different form from upstream fix.  I haven't looked at the
> older trees, but 4.9.y and later took the upstream fix as is, so this
> patch isn't needed for them.
> 
> The patch hasn't been tested with the real test case, though; let me
> know if the current code is intended.  Thanks!

Hm, I did the initial backport, and then Eric showed what I got wrong
and fixed that up, so being still wrong is not inconceivable at all :)

Have you tried testing this with the reproducer?  That might be the best
verification here.  If your testing proves to be good, I'll gladly take
this patch, thanks!

greg k-h

thanks,

greg k-h