crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ
authorOndrej Mosnacek <omosnace@redhat.com>
Tue, 3 May 2022 11:50:10 +0000 (13:50 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 25 May 2022 07:14:34 +0000 (09:14 +0200)
commit8be06f62b426801dba43ddf8893952a0e62ab6ae
tree2d0d0c14487aa5e617ff9215688ac148fd829c10
parentf4a093215b8e28878319d35c463000105e8cf06b
crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ

commit 16287397ec5c08aa58db6acf7dbc55470d78087d upstream.

The commit referenced in the Fixes tag removed the 'break' from the else
branch in qcom_rng_read(), causing an infinite loop whenever 'max' is
not a multiple of WORD_SZ. This can be reproduced e.g. by running:

    kcapi-rng -b 67 >/dev/null

There are many ways to fix this without adding back the 'break', but
they all seem more awkward than simply adding it back, so do just that.

Tested on a machine with Qualcomm Amberwing processor.

Fixes: a680b1832ced ("crypto: qcom-rng - ensure buffer for generate is completely filled")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/crypto/qcom-rng.c