diff options
| -rw-r--r-- | drivers/char/random.c | 13 |
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: /* |