Re: [PATCH net-next 1/3] ipv6: sr: Fix MAC comparison to be constant-time

[Eric Biggers <ebiggers@kernel.org>]

On Mon, Aug 18, 2025 at 07:38:52PM +0000, Eric Biggers wrote:
> On Mon, Aug 18, 2025 at 09:16:07PM +0200, Andrea Mayer wrote:
> > On Fri, 15 Aug 2025 20:11:34 -0700
> > Eric Biggers <ebiggers@kernel.org> wrote:
> > 
> > > To prevent timing attacks, MACs need to be compared in constant time.
> > > Use the appropriate helper function for this.
> > > 
> > > Fixes: bf355b8d2c30 ("ipv6: sr: add core files for SR HMAC support")
> > > Cc: stable@vger.kernel.org
> > > Signed-off-by: Eric Biggers <ebiggers@kernel.org>
> > > ---
> > >  net/ipv6/seg6_hmac.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > 
> > Hi Eric,
> > 
> > Thanks for the fix!
> > 
> > I believe it would be best to submit this fix separately from the current patch
> > set. Since this addresses a bug rather than an enhancement or cleanup, sending
> > it individually with the 'net' tag will help facilitate applying this patch to
> > the net tree.
> > 
> > Ciao,
> > Andrea
> 
> Then there would be a merge conflict between the two patchsets.
> 
> I can do that if you want, but then I'd probably have to wait for this
> patch to reach net-next before the rest can proceed.

I guess patches 2 and 3 have to wait for "ipv6: sr: validate HMAC
algorithm ID in seg6_hmac_info_add" anyway, as they conflict with that
too.  Okay, I resent patch 1 as a standalone patch targeting "net":
https://lore.kernel.org/netdev/20250818202724.15713-1-ebiggers@kernel.org/

- Eric