crypto: aesni - don't use GFP_ATOMIC allocation if the request doesn't cross a page...

This patch fixes gcmaes_crypt_by_sg so that it won't use memory
allocation if the data doesn't cross a page boundary.

Authenticated encryption may be used by dm-crypt. If the encryption or
decryption fails, it would result in I/O error and filesystem corruption.
The function gcmaes_crypt_by_sg is using GFP_ATOMIC allocation that can
fail anytime. This patch fixes the logic so that it won't attempt the
failing allocation if the data doesn't cross a page boundary.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
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 acbe7e8336d8556c272f915c7543d02132a852d3..e4b78f96287494d55eca9cc4d14fc4dfbc6e901f 100644 (file)
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -817,7 +817,7 @@ static int gcmaes_crypt_by_sg(bool enc, struct aead_request *req,
        /* Linearize assoc, if not already linear */
        if (req->src->length >= assoclen && req->src->length &&
                (!PageHighMem(sg_page(req->src)) ||
-                       req->src->offset + req->src->length < PAGE_SIZE)) {
+                       req->src->offset + req->src->length <= PAGE_SIZE)) {
                scatterwalk_start(&assoc_sg_walk, req->src);
                assoc = scatterwalk_map(&assoc_sg_walk);
        } else {