commit 81487b65b9eb8148471e729b8c1959521d62c69e
author Pauli <pauli@openssl.org> Wed Mar 16 14:13:25 2022 +1100
committer Pauli <pauli@openssl.org> Fri Mar 25 17:31:37 2022 +1100
tree e9b1a5006b767159f122e9b77d3fb278e6fada42
parent 288e9680399d3a755861d309058dda2fb48af8bf

Fix Coverity 1498612: integer overflow

The assert added cannot ever fail because (current & 0xFFFF) != 0 from the
while loop and the trailing zero bit count therefore cannot be as large as 32.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/17892)

crypto/ec/curve448/curve448.c

diff --git a/crypto/ec/curve448/curve448.c b/crypto/ec/curve448/curve448.c
index 9b9786d..4db72cd 100644
--- a/crypto/ec/curve448/curve448.c
+++ b/crypto/ec/curve448/curve448.c
@@ -586,6 +586,7 @@
             int32_t delta = odd & mask;
 
             assert(position >= 0);
+            assert(pos < 32);       /* can't fail since current & 0xFFFF != 0 */
             if (odd & (1 << (table_bits + 1)))
                 delta -= (1 << (table_bits + 1));
             current -= delta * (1 << pos);