[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/blkcipher.c b/crypto/blkcipher.c
index 6e93004f2181ccb3f265994cf9806db528641796..cbb4c4e5c229ca2ecd52b4ebdebb9027e4b42503 100644 (file)
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -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;

diff --git a/crypto/digest.c b/crypto/digest.c
index 8f4593268ce0bf5c5ef2e9e47d8ab72789adb842..bc47af648cb16dae48216e82785e76002f047d10 100644 (file)
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -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);
 }
 

diff --git a/crypto/xcbc.c b/crypto/xcbc.c
index 9347eb6bcf69dec5a971be9a9c805b6e548cc94d..317e9f08fc045ca7cee745c7418b606b11020ad8 100644 (file)
--- 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 @@ static int crypto_xcbc_digest_init(struct hash_desc *pdesc)
        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 @@ 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);
 }