Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto fix from Herbert Xu:
 "This fixes a bug on sparc where we may dereference freed stack memory"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: Work around deallocated stack frame reference gcc bug on sparc.

Author: torvalds

drivers/infiniband/sw/rxe/rxe.h

@@ -68,6 +68,7 @@
 static inline u32 rxe_crc32(struct rxe_dev *rxe,
 			    u32 crc, void *next, size_t len)
 {
+	u32 retval;
 	int err;
 
 	SHASH_DESC_ON_STACK(shash, rxe->tfm);
@@ -81,7 +82,9 @@ static inline u32 rxe_crc32(struct rxe_dev *rxe,
 		return crc32_le(crc, next, len);
 	}
 
-	return *(u32 *)shash_desc_ctx(shash);
+	retval = *(u32 *)shash_desc_ctx(shash);
+	barrier_data(shash_desc_ctx(shash));
+	return retval;
 }
 
 int rxe_set_mtu(struct rxe_dev *rxe, unsigned int dev_mtu);

fs/btrfs/hash.c

@@ -38,6 +38,7 @@ u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
 {
 	SHASH_DESC_ON_STACK(shash, tfm);
 	u32 *ctx = (u32 *)shash_desc_ctx(shash);
+	u32 retval;
 	int err;
 
 	shash->tfm = tfm;
@@ -47,5 +48,7 @@ u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
 	err = crypto_shash_update(shash, address, length);
 	BUG_ON(err);
 
-	return *ctx;
+	retval = *ctx;
+	barrier_data(ctx);
+	return retval;
 }

fs/f2fs/f2fs.h

@@ -1078,6 +1078,7 @@ static inline u32 f2fs_crc32(struct f2fs_sb_info *sbi, const void *address,
 {
 	SHASH_DESC_ON_STACK(shash, sbi->s_chksum_driver);
 	u32 *ctx = (u32 *)shash_desc_ctx(shash);
+	u32 retval;
 	int err;
 
 	shash->tfm = sbi->s_chksum_driver;
@@ -1087,7 +1088,9 @@ static inline u32 f2fs_crc32(struct f2fs_sb_info *sbi, const void *address,
 	err = crypto_shash_update(shash, address, length);
 	BUG_ON(err);
 
-	return *ctx;
+	retval = *ctx;
+	barrier_data(ctx);
+	return retval;
 }
 
 static inline bool f2fs_crc_valid(struct f2fs_sb_info *sbi, __u32 blk_crc,

lib/libcrc32c.c

@@ -43,7 +43,7 @@ static struct crypto_shash *tfm;
 u32 crc32c(u32 crc, const void *address, unsigned int length)
 {
 	SHASH_DESC_ON_STACK(shash, tfm);
-	u32 *ctx = (u32 *)shash_desc_ctx(shash);
+	u32 ret, *ctx = (u32 *)shash_desc_ctx(shash);
 	int err;
 
 	shash->tfm = tfm;
@@ -53,7 +53,9 @@ u32 crc32c(u32 crc, const void *address, unsigned int length)
 	err = crypto_shash_update(shash, address, length);
 	BUG_ON(err);
 
-	return *ctx;
+	ret = *ctx;
+	barrier_data(ctx);
+	return ret;
 }
 
 EXPORT_SYMBOL(crc32c);