Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull /dev/random updates from Ted Ts'o:
 "This adds a memzero_explicit() call which is guaranteed not to be
  optimized away by GCC.  This is important when we are wiping
  cryptographically sensitive material"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  crypto: memzero_explicit - make sure to clear out sensitive data
  random: add and use memzero_explicit() for clearing data

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 82759cef9043..04645c09fe5e 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1106,7 +1106,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
         __mix_pool_bytes(r, hash.w, sizeof(hash.w));
         spin_unlock_irqrestore(&r->lock, flags);
 
-        memset(workspace, 0, sizeof(workspace));
+        memzero_explicit(workspace, sizeof(workspace));
 
         /*
          * In case the hash function has some recognizable output
@@ -1118,7 +1118,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
         hash.w[2] ^= rol32(hash.w[2], 16);
 
         memcpy(out, &hash, EXTRACT_SIZE);
-        memset(&hash, 0, sizeof(hash));
+        memzero_explicit(&hash, sizeof(hash));
 }
 
 /*
@@ -1175,7 +1175,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
         }
 
         /* Wipe data just returned from memory */
-        memset(tmp, 0, sizeof(tmp));
+        memzero_explicit(tmp, sizeof(tmp));
 
         return ret;
 }
@@ -1218,7 +1218,7 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
         }
 
         /* Wipe data just returned from memory */
-        memset(tmp, 0, sizeof(tmp));
+        memzero_explicit(tmp, sizeof(tmp));
 
         return ret;
 }