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authorArd Biesheuvel <ardb@kernel.org>2020-07-21 09:05:54 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2020-07-31 18:09:00 +1000
commit958ea4e0d64e39d039245e6450f625108833e522 (patch)
tree2154c28f985065016cd67b4cd7aef640b947068b
parent28ee8b0912ca2ff68c2c03ff97bf1c22634c7942 (diff)
crypto: xts - Replace memcpy() invocation with simple assignment
Colin reports that the memcpy() call in xts_cts_final() trigggers a "Overlapping buffer in memory copy" warning in Coverity, which is a false postive, given that tail is guaranteed to be smaller than or equal to the distance between source and destination. However, given that any additional bytes that we copy will be ignored anyway, we can simply copy XTS_BLOCK_SIZE unconditionally, which means we can use struct assignment of the array members instead, which is likely to be more efficient as well. Addresses-Coverity: ("Overlapping buffer in memory copy") Fixes: 8083b1bf8163 ("crypto: xts - add support for ciphertext stealing") Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/xts.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/crypto/xts.c b/crypto/xts.c
index 3c3ed02c7663..ad45b009774b 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -171,7 +171,7 @@ static int xts_cts_final(struct skcipher_request *req,
offset - XTS_BLOCK_SIZE);
scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
- memcpy(b + 1, b, tail);
+ b[1] = b[0];
scatterwalk_map_and_copy(b, req->src, offset, tail, 0);
le128_xor(b, &rctx->t, b);