[patch 046/100] crypto: shash - Fix unaligned calculation with short length

Chris Wright
2009-04-23T07:41:33Z

[-- Attachment #1: crypto-shash-fix-unaligned-calculation-with-short-length.patch --]
[-- Type: text/plain, Size: 972 bytes --]

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

From: Yehuda Sadeh <yehuda@hq.newdream.net>

upstream commit: f4f689933c63e0fbfba62f2a80efb2b424b139ae

When the total length is shorter than the calculated number of unaligned bytes, the call to shash->update breaks. For example, calling crc32c on unaligned buffer with length of 1 can result in a system crash.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

crypto/shash.c | 3 +++
1 file changed, 3 insertions(+)

--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -82,6 +82,9 @@ static int shash_update_unaligned(struct
u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
__attribute__ ((aligned));

+ if (unaligned_len > len)
+ unaligned_len = len;
+
memcpy(buf, data, unaligned_len);

return shash->update(desc, buf, unaligned_len) ?: