Re: Kernel Bug Report

[Alexander Nyberg]

> > It looks like it panics during a mem_cpy but I know its
> > difficult to tell just by the output.
> > 
> > I get a code: f3 a4 c3 66 66 66 90 66 66 66 90 66 66 66 90 66
> > 
> > The problem appears very reproducable so I can provide more
> > information upon request.
> 
> What does the rest of the panic say? There should be text above this
> that tells where the panic occured and why. Can you please send that
> here?

Ok, could you please try the this patch, I'll attach it aswell:

From:	Andreas Steinmetz <ast@xxxxxxxx>

from include/linux/kernel.h:

#define ALIGN(x,a) (((x)+(a)-1)&~((a)-1))

from crypto/cipher.c:

unsigned int alignmask = ...
u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
...
unsigned int alignmask = ...
u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
...
unsigned int align;
addr = ALIGN(addr, align);
addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);

The compiler first does ~((a)-1)) and then expands the unsigned int to
unsigned long for the & operation. So we end up with only the lower 32
bits of the address. Who did smoke what to do this? Patch attached.
-- 
Andreas Steinmetz                       SPAMmers use robotrap@xxxxxxxx

--- linux.orig/crypto/cipher.c	2005-07-17 13:35:15.000000000 +0200
+++ linux/crypto/cipher.c	2005-07-17 14:04:00.000000000 +0200
@@ -41,7 +41,7 @@
 			       struct scatter_walk *in,
 			       struct scatter_walk *out, unsigned int bsize)
 {
-	unsigned int alignmask = crypto_tfm_alg_alignmask(desc->tfm);
+	unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
 	u8 buffer[bsize * 2 + alignmask];
 	u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 	u8 *dst = src + bsize;
@@ -160,7 +160,7 @@
 			      unsigned int nbytes)
 {
 	struct crypto_tfm *tfm = desc->tfm;
-	unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
+	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 	u8 *iv = desc->info;
 
 	if (unlikely(((unsigned long)iv & alignmask))) {
@@ -424,7 +424,7 @@
 	}
 	
 	if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
-		unsigned int align;
+		unsigned long align;
 		unsigned long addr;
 	    	
 	    	switch (crypto_tfm_alg_blocksize(tfm)) {

--------------080406080505060706090703--
-

> --- Begin Message ---
> from include/linux/kernel.h:
>
> #define ALIGN(x,a) (((x)+(a)-1)&~((a)-1))
>
> from crypto/cipher.c:
>
> unsigned int alignmask = ...
> u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> ...
> unsigned int alignmask = ...
> u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> ...
> unsigned int align;
> addr = ALIGN(addr, align);
> addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
>
> The compiler first does ~((a)-1)) and then expands the unsigned int to
> unsigned long for the & operation. So we end up with only the lower 32
> bits of the address. Who did smoke what to do this? Patch attached.
> -- 
> Andreas Steinmetz                       SPAMmers use robotrap@xxxxxxxx
>
> --- linux.orig/crypto/cipher.c	2005-07-17 13:35:15.000000000 +0200
> +++ linux/crypto/cipher.c	2005-07-17 14:04:00.000000000 +0200
> @@ -41,7 +41,7 @@
>  			       struct scatter_walk *in,
>  			       struct scatter_walk *out, unsigned int bsize)
>  {
> -	unsigned int alignmask = crypto_tfm_alg_alignmask(desc->tfm);
> +	unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
>  	u8 buffer[bsize * 2 + alignmask];
>  	u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
>  	u8 *dst = src + bsize;
> @@ -160,7 +160,7 @@
>  			      unsigned int nbytes)
>  {
>  	struct crypto_tfm *tfm = desc->tfm;
> -	unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
> +	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
>  	u8 *iv = desc->info;
>  
>  	if (unlikely(((unsigned long)iv & alignmask))) {
> @@ -424,7 +424,7 @@
>  	}
>  	
>  	if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
> -		unsigned int align;
> +		unsigned long align;
>  		unsigned long addr;
>  	    	
>  	    	switch (crypto_tfm_alg_blocksize(tfm)) {
>
> --------------080406080505060706090703--
> -
>
> --- End Message ---