crypto: shash - Fix unaligned calculation with short length

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>

1 files changed, 3 insertions, 0 deletions

diff --git a/crypto/shash.c b/crypto/shash.c
index 7a659733f94a..2ccc8b0076ce 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -77,6 +77,9 @@ static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
         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) ?: