[PATCH 3.18 23/84] dm crypt: use memzero_explicit for on-stack buffer

From: Greg Kroah-Hartman
Date: Tue Jan 06 2015 - 22:04:39 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Milan Broz <gmazyland@xxxxxxxxx>

commit 1a71d6ffe18c0d0f03fc8531949cc8ed41d702ee upstream.

Use memzero_explicit to cleanup sensitive data allocated on stack
to prevent the compiler from optimizing and removing memset() calls.

Signed-off-by: Milan Broz <gmazyland@xxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/md/dm-crypt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -705,7 +705,7 @@ static int crypt_iv_tcw_whitening(struct
for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
crypto_xor(data + i * 8, buf, 8);
out:
- memset(buf, 0, sizeof(buf));
+ memzero_explicit(buf, sizeof(buf));
return r;
}



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