summaryrefslogtreecommitdiff
path: root/drivers/char/random.c
diff options
context:
space:
mode:
authorAndy Lutomirski <luto@kernel.org>2019-12-23 00:20:46 -0800
committerTheodore Ts'o <tytso@mit.edu>2020-01-07 16:07:00 -0500
commit75551dbf112c992bc6c99a972990b3f272247e23 (patch)
tree14f6622786b61f5e244eb9c0ec402e3d64cd8faa /drivers/char/random.c
parentc6f1deb158789abba02a7eba600747843eeb3a57 (diff)
random: add GRND_INSECURE to return best-effort non-cryptographic bytes
Signed-off-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/d5473b56cf1fa900ca4bd2b3fc1e5b8874399919.1577088521.git.luto@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r--drivers/char/random.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 91954c0091a5..b7e2ad7eafca 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2194,7 +2194,14 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
{
int ret;
- if (flags & ~(GRND_NONBLOCK|GRND_RANDOM))
+ if (flags & ~(GRND_NONBLOCK|GRND_RANDOM|GRND_INSECURE))
+ return -EINVAL;
+
+ /*
+ * Requesting insecure and blocking randomness at the same time makes
+ * no sense.
+ */
+ if ((flags & (GRND_INSECURE|GRND_RANDOM)) == (GRND_INSECURE|GRND_RANDOM))
return -EINVAL;
if (count > INT_MAX)
@@ -2203,7 +2210,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
if (flags & GRND_RANDOM)
return _random_read(flags & GRND_NONBLOCK, buf, count);
- if (!crng_ready()) {
+ if (!(flags & GRND_INSECURE) && !crng_ready()) {
if (flags & GRND_NONBLOCK)
return -EAGAIN;
ret = wait_for_random_bytes();