crypto: aesni - xts_crypt() return if walk.nbytes is 0

xts_crypt() code doesn't call kernel_fpu_end() after calling
kernel_fpu_begin() if walk.nbytes is 0. The correct behavior should be
not calling kernel_fpu_begin() if walk.nbytes is 0.

Reported-by: syzbot+20191dc583eff8602d2d@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 388643c..0fc961b 100644 (file)
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -849,7 +849,7 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
                return -EINVAL;
 
        err = skcipher_walk_virt(&walk, req, false);
-       if (err)
+       if (!walk.nbytes)
                return err;
 
        if (unlikely(tail > 0 && walk.nbytes < walk.total)) {