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 07:17:56 +0000 (09:17 +0200)
commit233a3cc60e7a8fe0be8cf9934ae7b67ba25a866c
tree1635846424ebf7321e32f3b5d280e73a3844a3ba
parent6013ef5f51e0861a904b74a694e621bb451fe7ae
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