blob: 46a0624dd4e7d269a33b36a419b088b1a0d52891 [file] [log] [blame]
From 16287397ec5c08aa58db6acf7dbc55470d78087d Mon Sep 17 00:00:00 2001
From: Ondrej Mosnacek <>
Date: Tue, 3 May 2022 13:50:10 +0200
Subject: crypto: qcom-rng - fix infinite loop on requests not multiple of WORD_SZ
From: Ondrej Mosnacek <>
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")
Signed-off-by: Ondrej Mosnacek <>
Reviewed-by: Brian Masney <>
Signed-off-by: Herbert Xu <>
Signed-off-by: Greg Kroah-Hartman <>
drivers/crypto/qcom-rng.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/crypto/qcom-rng.c
+++ b/drivers/crypto/qcom-rng.c
@@ -64,6 +64,7 @@ static int qcom_rng_read(struct qcom_rng
} else {
/* copy only remaining bytes */
memcpy(data, &val, max - currsize);
+ break;
} while (currsize < max);