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authorOndrej Mosnacek <omosnace@redhat.com>2018-09-13 10:51:31 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2018-09-21 13:24:51 +0800
commitfbe1a850b3b1522e9fc22319ccbbcd2ab05328d2 (patch)
tree7e126126eafb2856eb49c54a2bb2e79ccc39e559 /crypto
parent331351f89c36bf7d03561a28b6f64fa10a9f6f3a (diff)
downloadlinux-stericsson-fbe1a850b3b1522e9fc22319ccbbcd2ab05328d2.tar.gz
crypto: lrw - Fix out-of bounds access on counter overflow
When the LRW block counter overflows, the current implementation returns 128 as the index to the precomputed multiplication table, which has 128 entries. This patch fixes it to return the correct value (127). Fixes: 64470f1b8510 ("[CRYPTO] lrw: Liskov Rivest Wagner, a tweakable narrow block cipher mode") Cc: <stable@vger.kernel.org> # 2.6.20+ Reported-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/lrw.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/crypto/lrw.c b/crypto/lrw.c
index 393a782679c7..5504d1325a56 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -143,7 +143,12 @@ static inline int get_index128(be128 *block)
return x + ffz(val);
}
- return x;
+ /*
+ * If we get here, then x == 128 and we are incrementing the counter
+ * from all ones to all zeros. This means we must return index 127, i.e.
+ * the one corresponding to key2*{ 1,...,1 }.
+ */
+ return 127;
}
static int post_crypt(struct skcipher_request *req)