[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: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/xcbc.c b/crypto/xcbc.c
index 9347eb6..317e9f08 100644
--- a/crypto/xcbc.c
+++ b/crypto/xcbc.c
@@ -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>
@@ -108,9 +109,9 @@
return 0;
}
-static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
- struct scatterlist *sg,
- unsigned int nbytes)
+static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
+ struct scatterlist *sg,
+ unsigned int nbytes)
{
struct crypto_hash *parent = pdesc->tfm;
struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
@@ -183,6 +184,15 @@
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(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);
}