crypto: shash - Fix unaligned calculation with short length

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>

diff --git a/crypto/shash.c b/crypto/shash.c
index d5a2b619c55f79e3b7cbff1f1d06d3048364b49c..6792a675c8b70e9bc137bd7dcd8cbc2c7758a9a1 100644 (file)
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -82,6 +82,9 @@ 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) ?: