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Commit fb469840 authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] all: Check for usage in hard IRQ context 



Using blkcipher/hash crypto operations in hard IRQ context can lead
to random memory corruption due to the reuse of kmap_atomic slots.
Since crypto operations were never meant to be used in hard IRQ
contexts, this patch checks for such usage and returns an error
before kmap_atomic is performed.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 62d0cfcb

crypto/blkcipher.c

+4 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 


#include <linux/crypto.h>

#include <linux/errno.h>

#include <linux/hardirq.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/scatterlist.h>
@@ -313,6 +314,9 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc, 
	struct crypto_blkcipher *tfm = desc->tfm;

	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);



	if (WARN_ON_ONCE(in_irq()))

		return -EDEADLK;



	walk->nbytes = walk->total;

	if (unlikely(!walk->total))

		return 0;

crypto/digest.c

+16 −3
Original line number Diff line number Diff line
@@ -14,7 +14,9 @@ 


#include <linux/mm.h>

#include <linux/errno.h>

#include <linux/hardirq.h>

#include <linux/highmem.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/scatterlist.h>
@@ -29,7 +31,7 @@ static int init(struct hash_desc *desc) 
	return 0;

}



static int update(struct hash_desc *desc,

static int update2(struct hash_desc *desc,

		   struct scatterlist *sg, unsigned int nbytes)

{

	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
@@ -81,6 +83,14 @@ static int update(struct hash_desc *desc, 
	return 0;

}



static int update(struct hash_desc *desc,

		  struct scatterlist *sg, unsigned int nbytes)

{

	if (WARN_ON_ONCE(in_irq()))

		return -EDEADLK;

	return update2(desc, sg, nbytes);

}



static int final(struct hash_desc *desc, u8 *out)

{

	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
@@ -118,8 +128,11 @@ static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen) 
static int digest(struct hash_desc *desc,

		  struct scatterlist *sg, unsigned int nbytes, u8 *out)

{

	if (WARN_ON_ONCE(in_irq()))

		return -EDEADLK;



	init(desc);

	update(desc, sg, nbytes);

	update2(desc, sg, nbytes);

	return final(desc, out);

}

crypto/xcbc.c

+17 −4
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 


#include <linux/crypto.h>

#include <linux/err.h>

#include <linux/hardirq.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/rtnetlink.h>
@@ -108,7 +109,7 @@ static int crypto_xcbc_digest_init(struct hash_desc *pdesc) 
	return 0;

}



static int crypto_xcbc_digest_update(struct hash_desc *pdesc,

static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,

				      struct scatterlist *sg,

				      unsigned int nbytes)

{
@@ -183,6 +184,15 @@ static int crypto_xcbc_digest_update(struct hash_desc *pdesc, 
	return 0;

}



static int crypto_xcbc_digest_update(struct hash_desc *pdesc,

				     struct scatterlist *sg,

				     unsigned int nbytes)

{

	if (WARN_ON_ONCE(in_irq()))

		return -EDEADLK;

	return crypto_xcbc_digest_update2(pdesc, sg, nbytes);

}



static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)

{

	struct crypto_hash *parent = pdesc->tfm;
@@ -234,8 +244,11 @@ static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out) 
static int crypto_xcbc_digest(struct hash_desc *pdesc,

		  struct scatterlist *sg, unsigned int nbytes, u8 *out)

{

	if (WARN_ON_ONCE(in_irq()))

		return -EDEADLK;



	crypto_xcbc_digest_init(pdesc);

	crypto_xcbc_digest_update(pdesc, sg, nbytes);

	crypto_xcbc_digest_update2(pdesc, sg, nbytes);

	return crypto_xcbc_digest_final(pdesc, out);

}