This is a note to let you know that I've just added the patch titled
crypto: ecc - Fix off-by-one missing to clear most significant digit
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-ecc-fix-off-by-one-missing-to-clear-most-sign.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 26727b72c076b28ee9ea8d77952bcf92a49033b4
Author: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Date: Thu Jun 13 17:38:20 2024 -0400
crypto: ecc - Fix off-by-one missing to clear most significant digit
[ Upstream commit 1dcf865d3bf5bff45e93cb2410911b3428dacb78 ]
Fix an off-by-one error where the most significant digit was not
initialized leading to signature verification failures by the testmgr.
Example: If a curve requires ndigits (=9) and diff (=2) indicates that
2 digits need to be set to zero then start with digit 'ndigits - diff' (=7)
and clear 'diff' digits starting from there, so 7 and 8.
Reported-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/linux-crypto/619bc2de-b18a-4939-a652-9ca886bf6349@xxxxxxxxxxxxx/T/#m045d8812409ce233c17fcdb8b88b6629c671f9f4
Fixes: 2fd2a82ccbfc ("crypto: ecdsa - Use ecc_digits_from_bytes to create hash digits array")
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Tested-by: Venkat Rao Bagalkote <venkat88@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/crypto/ecc.c b/crypto/ecc.c
index fe761256e335..dd48d9928a21 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -78,7 +78,7 @@ void ecc_digits_from_bytes(const u8 *in, unsigned int nbytes,
/* diff > 0: not enough input bytes: set most significant digits to 0 */
if (diff > 0) {
ndigits -= diff;
- memset(&out[ndigits - 1], 0, diff * sizeof(u64));
+ memset(&out[ndigits], 0, diff * sizeof(u64));
}
if (o) {
