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

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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: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu
2006-12-10 10:45:28 +11:00
parent 62d0cfcb27
commit fb469840b8
3 changed files with 37 additions and 7 deletions
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19
crypto/digest.c
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@@ -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>
@@ -29,8 +31,8 @@ static int init(struct hash_desc *desc)
return 0;
}
static int update(struct hash_desc *desc,
struct scatterlist *sg, unsigned int nbytes)
static int update2(struct hash_desc *desc,
struct scatterlist *sg, unsigned int nbytes)
{
struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
unsigned int alignmask = crypto_tfm_alg_alignmask(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);
}