Re: [REPOST PATCH] crypto: caam - reject overlong RSA CRT parameters

[Herbert Xu]

On Thu, Oct 15, 2026 at 08:28:50PM +1100, Herbert Xu wrote:
> On Thu, Oct 08, 2026 at 09:35:53AM +0000, Jérémy Jean wrote:
> > caam_read_rsa_crt() right-aligns dP, dQ, and qInv in buffers sized
> > from the corresponding prime. rsa_parse_priv_key() only bounds these
> > integers against n, so a malformed key can provide, for example, a
> > two-byte dP with a one-byte p. dstlen - nbytes then underflows and
> > memcpy() writes outside the allocation during set_priv_key(). KASAN
> > reports a slab-out-of-bounds write in caam_read_rsa_crt().
> > 
> > Reject empty or overlong CRT parameters after stripping leading zeros.
> > qInv is consumed by CAAM as a p-sized value, so size it from p rather
> > than q to match the DMA mapping in set_rsa_priv_f3_pdb(). Let the
> > top-level key cleanup handle partial form-3 allocations and return the
> > specific error to the caller.
> > 
> > Also test nbytes before dereferencing it while stripping zeros, so an
> > all-zero integer does not read one byte beyond its input.
> > 
> > Fixes: 4a651b122adb ("crypto: caam - add support for RSA key form 3")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Assisted-by: LLM
> > Signed-off-by: Jérémy Jean <Jeremy.Jean@xxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/crypto/caam/caampkc.c | 69 +++++++++++++++--------------------
> >  1 file changed, 30 insertions(+), 39 deletions(-)
> 
> Sahil, could you please review this patch?

Hi Sahil:

It's been two weeks and you've provided no feedback.

If there isn't going to be timely feedback to patches on this
driver then it will be removed.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt