From 16287397ec5c08aa58db6acf7dbc55470d78087d Mon Sep 17 00:00:00 2001
From: Ondrej Mosnacek <omosnace@redhat.com>
Date: Tue, 3 May 2022 13:50:10 +0200
Subject: [PATCH] crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ
Git-commit: 16287397ec5c08aa58db6acf7dbc55470d78087d
Patch-mainline: v5.18
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/crypto/qcom-rng.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/crypto/qcom-rng.c b/drivers/crypto/qcom-rng.c
index 11f30fd48c14..031b5f701a0a 100644
--- a/drivers/crypto/qcom-rng.c
+++ b/drivers/crypto/qcom-rng.c
@@ -65,6 +65,7 @@ static int qcom_rng_read(struct qcom_rng *rng, u8 *data, unsigned int max)
 		} else {
 			/* copy only remaining bytes */
 			memcpy(data, &val, max - currsize);
+			break;
 		}
 	} while (currsize < max);
 
-- 
2.35.3