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Subject[PATCH 4.19 31/99] crypto: sm3 - fix undefined shift by >= width of value
Date
4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@google.com>

commit d45a90cb5d061fa7d411b974b950fe0b8bc5f265 upstream.

sm3_compress() calls rol32() with shift >= 32, which causes undefined
behavior. This is easily detected by enabling CONFIG_UBSAN.

Explicitly AND with 31 to make the behavior well defined.

Fixes: 4f0fc1600edb ("crypto: sm3 - add OSCCA SM3 secure hash")
Cc: <stable@vger.kernel.org> # v4.15+
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/sm3_generic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/crypto/sm3_generic.c
+++ b/crypto/sm3_generic.c
@@ -100,7 +100,7 @@ static void sm3_compress(u32 *w, u32 *wt

for (i = 0; i <= 63; i++) {

- ss1 = rol32((rol32(a, 12) + e + rol32(t(i), i)), 7);
+ ss1 = rol32((rol32(a, 12) + e + rol32(t(i), i & 31)), 7);

ss2 = ss1 ^ rol32(a, 12);


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