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-rw-r--r--drivers/char/random.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 783dee11cdc9..8d0af74f6569 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -738,15 +738,18 @@ retry:
}
}
-static void credit_entropy_bits_safe(struct entropy_store *r, int nbits)
+static int credit_entropy_bits_safe(struct entropy_store *r, int nbits)
{
const int nbits_max = (int)(~0U >> (ENTROPY_SHIFT + 1));
+ if (nbits < 0)
+ return -EINVAL;
+
/* Cap the value to avoid overflows */
nbits = min(nbits, nbits_max);
- nbits = max(nbits, -nbits_max);
credit_entropy_bits(r, nbits);
+ return 0;
}
/*********************************************************************
@@ -1823,8 +1826,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
return -EPERM;
if (get_user(ent_count, p))
return -EFAULT;
- credit_entropy_bits_safe(&input_pool, ent_count);
- return 0;
+ return credit_entropy_bits_safe(&input_pool, ent_count);
case RNDADDENTROPY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -1838,8 +1840,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
size);
if (retval < 0)
return retval;
- credit_entropy_bits_safe(&input_pool, ent_count);
- return 0;
+ return credit_entropy_bits_safe(&input_pool, ent_count);
case RNDZAPENTCNT:
case RNDCLEARPOOL:
/*