[PATCH] crypto: add missing kernel_fpu_end() call

[Shreyansh Chouhan]

xts_crypt() code doesn't call kernel_fpu_end() after calling
kernel_fpu_begin() if walk.nbytes is 0. Add a call to kernel_fpu_end()
for this case.

Reported-by: syzbot+20191dc583eff8602d2d@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@xxxxxxxxx>
---
 arch/x86/crypto/aesni-intel_glue.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 2144e54a6c89..bd55a0cd7bde 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -894,6 +894,9 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
 			kernel_fpu_begin();
 	}
 
+	if (walk.nbytes == 0)
+		kernel_fpu_end();
+
 	if (unlikely(tail > 0 && !err)) {
 		struct scatterlist sg_src[2], sg_dst[2];
 		struct scatterlist *src, *dst;
-- 
2.31.1