tree 8b84e1c7a18df7c134d32cbe587cd6d88c9e942e
parent 6212f2c7f70c591efb0d9f3d50ad29112392fee2
author Joy Latten <latten@austin.ibm.com> 1204802924 +0800
committer Herbert Xu <herbert@gondor.apana.org.au> 1204802924 +0800

[CRYPTO] xcbc: Fix crash with IPsec

When using aes-xcbc-mac for authentication in IPsec, 
the kernel crashes. It seems this algorithm doesn't 
account for the space IPsec may make in scatterlist for authtag.
Thus when crypto_xcbc_digest_update2() gets called,
nbytes may be less than sg[i].length. 
Since nbytes is an unsigned number, it wraps
at the end of the loop allowing us to go back 
into loop and causing crash in memcpy.

I used update function in digest.c to model this fix.
Please let me know if it looks ok.

Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>