From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 458FF3537EF; Wed, 8 Apr 2026 18:28:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672912; cv=none; b=nDUEZVEtUUln26N6kl2fqQOCf/4g30HFp53XIL01fOAODlZjb+HvKT4kGsU7LLdh/P2azQBCXJiTs6q6hv91RaixwYsWFYT6/HaPgvvGRCGP9OLfiTfR14Qn/BiC/XRVNWciokR9pdSRZmwT07S4FtNhx2Uo3z533uMCXlGAmpU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672912; c=relaxed/simple; bh=ZWbLcg5sFmS1DsrSjRB4lDuOx+btpVxPeCHxVpn7mw4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f6ceXzSFLADoGdJHKdmiyznEsa7ljNLQP289BjX13UcTmP7vgcTgNaB7AidBerOkGpOtXdCmJQQa8MFtSG4PyegmVFDe6b37stnzfBjH7nokaQq6L7lQykXswUGAU2wGD0MYNBnS4+uUqFDpBz+tgJGOVk/VpsEzBl0nRLclEEs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OGvBAXjK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OGvBAXjK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D184DC19421; Wed, 8 Apr 2026 18:28:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775672912; bh=ZWbLcg5sFmS1DsrSjRB4lDuOx+btpVxPeCHxVpn7mw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OGvBAXjKDC2+cQNWF13Llf+AnqJnZ9QlUPEZr9qY/+LhSfLY+3MAbbGAVAk2hQrJM NtlbLCpHH2s4pQC9c2GZaoiFeqMl2HYXiEao4IUEW42TwcJOX5c98CwdewOegTKtcS OqlLxg2R/CODVJPxxccRlYNCioR3DiMWZi7nbf1Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Norbert Szetei , Herbert Xu , Sasha Levin Subject: [PATCH 6.18 028/277] crypto: af-alg - fix NULL pointer dereference in scatterwalk Date: Wed, 8 Apr 2026 20:00:13 +0200 Message-ID: <20260408175934.903778726@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.836769063@linuxfoundation.org> References: <20260408175933.836769063@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Norbert Szetei [ Upstream commit 62397b493e14107ae82d8b80938f293d95425bcb ] The AF_ALG interface fails to unmark the end of a Scatter/Gather List (SGL) when chaining a new af_alg_tsgl structure. If a sendmsg() fills an SGL exactly to MAX_SGL_ENTS, the last entry is marked as the end. A subsequent sendmsg() allocates a new SGL and chains it, but fails to clear the end marker on the previous SGL's last data entry. This causes the crypto scatterwalk to hit a premature end, returning NULL on sg_next() and leading to a kernel panic during dereference. Fix this by explicitly unmarking the end of the previous SGL when performing sg_chain() in af_alg_alloc_tsgl(). Fixes: 8ff590903d5f ("crypto: algif_skcipher - User-space interface for skcipher operations") Signed-off-by: Norbert Szetei Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- crypto/af_alg.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 6c271e55f44d9..78e995dddf879 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -623,8 +623,10 @@ static int af_alg_alloc_tsgl(struct sock *sk) sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); sgl->cur = 0; - if (sg) + if (sg) { + sg_unmark_end(sg + MAX_SGL_ENTS - 1); sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); + } list_add_tail(&sgl->list, &ctx->tsgl_list); } -- 2.53.0