Re: Fw: [Bugme-new] [Bug 5194] New: IPSec related OOps in 2.6.13

[Herbert Xu <herbert@gondor.apana.org.au>]

On Tue, Sep 06, 2005 at 04:08:56AM -0700, Andrew Morton wrote:
> 
> Problem Description:
> 
> Oops: 0000 [#1]
> PREEMPT
> Modules linked in:
> CPU:    0
> EIP:    0060:[<c01f562c>]    Not tainted VLI
> EFLAGS: 00010216   (2.6.13)
> EIP is at sha1_update+0x7c/0x160

Thanks for the report.  Matt LaPlante had exactly the same problem
a couple of days ago.  I've tracked down now to my broken crypto
cipher wrapper functions which will step over a page boundary if
it's not aligned correctly.


[CRYPTO] Fix boundary check in standard multi-block cipher processors

The boundary check in the standard multi-block cipher processors are
broken when nbytes is not a multiple of bsize.  In those cases it will
always process an extra block.

This patch corrects the check so that it processes at most nbytes of data.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

diff --git a/crypto/cipher.c b/crypto/cipher.c
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -191,6 +191,8 @@ static unsigned int cbc_process_encrypt(
 	u8 *iv = desc->info;
 	unsigned int done = 0;
 
+	nbytes -= bsize;
+
 	do {
 		xor(iv, src);
 		fn(crypto_tfm_ctx(tfm), dst, iv);
@@ -198,7 +200,7 @@ static unsigned int cbc_process_encrypt(
 
 		src += bsize;
 		dst += bsize;
-	} while ((done += bsize) < nbytes);
+	} while ((done += bsize) <= nbytes);
 
 	return done;
 }
@@ -219,6 +221,8 @@ static unsigned int cbc_process_decrypt(
 	u8 *iv = desc->info;
 	unsigned int done = 0;
 
+	nbytes -= bsize;
+
 	do {
 		u8 *tmp_dst = *dst_p;
 
@@ -230,7 +234,7 @@ static unsigned int cbc_process_decrypt(
 
 		src += bsize;
 		dst += bsize;
-	} while ((done += bsize) < nbytes);
+	} while ((done += bsize) <= nbytes);
 
 	return done;
 }
@@ -243,12 +247,14 @@ static unsigned int ecb_process(const st
 	void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
 	unsigned int done = 0;
 
+	nbytes -= bsize;
+
 	do {
 		fn(crypto_tfm_ctx(tfm), dst, src);
 
 		src += bsize;
 		dst += bsize;
-	} while ((done += bsize) < nbytes);
+	} while ((done += bsize) <= nbytes);
 
 	return done;
 }