From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794050376; b=iepePM1C88MQhqqoChz6mhv+0jBjxp8FxV2eiBqR7y4saeE/R9ub+3K97O/dBOOs0fQU vU03RkZvCzrEUEpwc0urbH5nA4ua+QD+ZhxETvojxvvcghOuthtcW4SB5PW+ciyySZgLP s1PgGchf/QuMUdPK8ozifJnbDoE5hYj8eVeWfXEUtFTnrzh0E4kfa9EPPJftcbIXxbYbT zIgafhohgexCZcFqqor+8c4ZunzfwABSS27nGhoQ8KRLffhbClLOQgpKQjkUFoi2boBWC dbM8KQqxENUxLOUJjh08Oyq5Jh93uwQbvbpiak5tmMe1v9EVTeqORLLGuhAfUklSeMw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794050376; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=Z9lpd7pY+LoJ+M/46ZlsWto746shTrQGXyvxjJuoivA=; b=oGSD3zMkS5N/nAWJ13emhLrZ5OcLLYfNG9JUCct9bZc9zFc2rbl/zyOulrGjUbGvkyl5 RDhYAhBUfTAkwC65fIRbW5m/SmJ2aKgzo/e18ftmOqvrfifd5CzTwgoqIkxtFAm2OIZz2 S7Lv2BTdRmiBCM9SzzxqWQhla7dtfUUQoSfGXM1MprUaiA3dKqnT4e2glGKYuXEEMgSbl a7F+6pmx7XZzqdR5rXVguCdqZEsmo2TnKoFAOULyNhM3R4TKlM3Dl9tw8kuTmHEt/6LJi rXBJW3UPjV0f4TI0AFc141G784+v2tezD/z5T4iXqVwYDlCFFNxqUmEMUFaJqPrij/g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="BH3Xa/JG"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 27506606A32C for ; Sat, 7 Nov 2026 11:19:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BH3Xa/JG Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B3CF1F0089F; Sat, 7 Nov 2026 11:19:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794050375; bh=Z9lpd7pY+LoJ+M/46ZlsWto746shTrQGXyvxjJuoivA=; h=From:To:Cc:Subject:Date; b=BH3Xa/JGsslXUF0lMLAZABmGobXNMaDECm9P5iV2Ywi8A37nceKCFnCZRPkcRfwf0 yKz+frGGBlGkwhz8vShJoZWOXz050pG7zSzvNbfJFE6tADnwEL9XfYk1SWQrPxW0jw YG6iiKD+v2iKlk6iw/KZ/htgpbcehRiJM6vhR4j+hWXyaNnfb5bojrA7MFrmwuWw7Z jKRbKj/g5FCQhM0k8YypY8Nu4QwYn77nJJQ4ZkgW2pVGa3dYpHYDC5+6wWyG0LUGf2 oCPDYwZxvNRRrnfOSnoHi5NH09Mj2BRVFzIjlFCEilnAVaL2qcNLm4IxxK9fvOY+Z3 qvqDcfYlIuUNw== From: Sasha Levin To: 4ncienth@gmail.com, herbert@gondor.apana.org.au Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] crypto: algif_skcipher - rewind rounded output bytes" failed to apply to 5.10-stable tree Date: Sat, 7 Nov 2026 06:19:34 -0500 Message-ID: <20261107061933-failed-5.10-2f90facc7b94@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 2f90facc7b94934653eb7ebfadcc25d503b89196 # git commit -s git send-email --to '' --in-reply-to '20261107061933-failed-5.10-2f90facc7b94@kernel.org' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 2f90facc7b94934653eb7ebfadcc25d503b89196 Mon Sep 17 00:00:00 2001 From: Daehyeon Ko <4ncienth@gmail.com> Date: Sun, 4 Oct 2026 14:09:46 +0900 Subject: [PATCH] crypto: algif_skcipher - rewind rounded output bytes af_alg_get_rsgl() advances the receive iterator by the unrounded RX scatterlist length. For a continuing skcipher request, _skcipher_recvmsg() then rounds its local length down to a whole chunksize without restoring the iterator. A later chunk starts after bytes which the provider never wrote, while the syscall returns only the processed length. When copy_splice_read() supplies non-zeroed pages and publishes that return as a dense prefix, the gap exposes stale bytes from a previous page lifetime. With unprivileged xts(aes), a 31-byte MSG_MORE request followed by one final byte advances a 47-byte destination while returning 32 bytes. A hardened v7.2-rc5 image retained all 15 seeded stale bytes in 4,829 of 4,829 records. With init_on_alloc enabled, all 72,345 gap bytes observed were zero. Rewind the iterator by the tail excluded during rounding, before rejecting a zero processed length. The crypto request uses only the rounded length; af_alg_free_resources() releases the entire RX list before another receive iteration. The fixed target-like kernel returned byte-identical dense 48-byte output in 4,771 of 4,771 rounds. The unmodified kernel returned the vulnerable 32-byte short record in 2,409 of 2,409 rounds. Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Signed-off-by: Herbert Xu --- crypto/algif_skcipher.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index 1e61fe6e24b99..291dbd6989325 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -135,12 +135,16 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg, * full block size buffers. */ if (ctx->more || len < ctx->used) { - if (len < bs) { + size_t excess = len % bs; + + len -= excess; + iov_iter_revert(&msg->msg_iter, excess); + + if (!len) { err = -EINVAL; goto free; } - len -= len % bs; cflags |= CRYPTO_SKCIPHER_REQ_NOTFINAL; } -- 2.53.0