[PATCH v5 2/2] KEYS: asymmetric: Copy sig and digest in public_key_verify_signature()

[Jarkko Sakkinen]

On Thu, Feb 09, 2023 at 06:53:37PM +0000, Eric Biggers wrote:
> On Thu, Feb 09, 2023 at 11:49:19AM +0100, Roberto Sassu wrote:
> > On Fri, 2023-01-27 at 09:27 +0100, Roberto Sassu wrote:
> > > On Thu, 2022-12-29 at 14:39 -0800, Eric Biggers wrote:
> > > > On Tue, Dec 27, 2022 at 03:27:40PM +0100, Roberto Sassu wrote:
> > > > > From: Roberto Sassu <roberto.sassu at huawei.com>
> > > > > 
> > > > > Commit ac4e97abce9b8 ("scatterlist: sg_set_buf() argument must be in linear
> > > > > mapping") checks that both the signature and the digest reside in the
> > > > > linear mapping area.
> > > > > 
> > > > > However, more recently commit ba14a194a434c ("fork: Add generic vmalloced
> > > > > stack support") made it possible to move the stack in the vmalloc area,
> > > > > which is not contiguous, and thus not suitable for sg_set_buf() which needs
> > > > > adjacent pages.
> > > > > 
> > > > > Always make a copy of the signature and digest in the same buffer used to
> > > > > store the key and its parameters, and pass them to sg_init_one(). Prefer it
> > > > > to conditionally doing the copy if necessary, to keep the code simple. The
> > > > > buffer allocated with kmalloc() is in the linear mapping area.
> > > > > 
> > > > > Cc: stable at vger.kernel.org # 4.9.x
> > > > > Fixes: ba14a194a434 ("fork: Add generic vmalloced stack support")
> > > > > Link: https://lore.kernel.org/linux-integrity/Y4pIpxbjBdajymBJ@sol.localdomain/
> > > > > Suggested-by: Eric Biggers <ebiggers at kernel.org>
> > > > > Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
> > > > > ---
> > > > >  crypto/asymmetric_keys/public_key.c | 38 ++++++++++++++++-------------
> > > > >  1 file changed, 21 insertions(+), 17 deletions(-)
> > > > 
> > > > Reviewed-by: Eric Biggers <ebiggers at google.com>
> > > 
> > > Hi David
> > > 
> > > could you please take this patch in your repo, if it is ok?
> > 
> > Kindly ask your support here. Has this patch been queued somewhere?
> > Wasn't able to find it, also it is not in linux-next.
> > 
> 
> The maintainer of asymmetric_keys (David Howells) is ignoring this patch, so
> you'll need to find someone else to apply it.  Herbert Xu, the maintainer of the
> crypto subsystem, might be willing to apply it.  Or maybe Jarkko Sakkinen, who
> is a co-maintainer of the keyrings subsystem (but not asymmetric_keys, for some
> reason; should that change?).

I can apply this if no objections?

BR, Jarkko