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 7867BA32; Tue, 22 Jul 2025 14:02:33 +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=1753192953; cv=none; b=Ces4tdkyPLK3ijKy5Xy8egYMdzMZHKBMWJtB8DW7Zig3ownfT/3KWLi340LTl48fybe5Sl/myQiyQ/jCpXuuD11yJVVpiXFnes73EOnxZYYksFYYszH1iOwQ+izA19pnxIVFwT3qpb6Xe9JAik5JHXjR2SbuzNsGVYOnNdlPuAg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753192953; c=relaxed/simple; bh=CcL7P1twAhA3kEvl4gE0fU96TvNy+DRuOXHkRMVrKlA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H4zAMzHJaPedTmv2hU5UYZaDbIBu1j/dX3um7FEOEioeSRqrTr070b5loU1ttAuV+K41QGNmyb+J3VBON7qR2+866LCXgq2g6oDSJlVd4feFHTpIu3AdATfAXeuuXLdpcPPF3T3lnYgHNGdBwjPIqGbjoazBCp+d0ILFfhYVRBQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=creGQ68x; 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="creGQ68x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A217BC4CEEB; Tue, 22 Jul 2025 14:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1753192953; bh=CcL7P1twAhA3kEvl4gE0fU96TvNy+DRuOXHkRMVrKlA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=creGQ68x5H9/NykskFiW4muWkw11N6LfqmvYVYaq0pu7aERYzQKhVUzr0giafWJOi vbk5TiyVLG6XXBLN3425OSLWkf1gXnx0idahyvf1ZnnfIugHYUvNB/dOqCvv8VfEZ5 lBjp+nfg8Mr2i4zGjLfmAsaPDlPVGmgw1dX94PYw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Paulo Alcantara (Red Hat)" , Wang Zhaolong , Steve French Subject: [PATCH 6.12 064/158] smb: client: fix use-after-free in crypt_message when using async crypto Date: Tue, 22 Jul 2025 15:44:08 +0200 Message-ID: <20250722134343.145088225@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250722134340.596340262@linuxfoundation.org> References: <20250722134340.596340262@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wang Zhaolong commit b220bed63330c0e1733dc06ea8e75d5b9962b6b6 upstream. The CVE-2024-50047 fix removed asynchronous crypto handling from crypt_message(), assuming all crypto operations are synchronous. However, when hardware crypto accelerators are used, this can cause use-after-free crashes: crypt_message() // Allocate the creq buffer containing the req creq = smb2_get_aead_req(..., &req); // Async encryption returns -EINPROGRESS immediately rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); // Free creq while async operation is still in progress kvfree_sensitive(creq, ...); Hardware crypto modules often implement async AEAD operations for performance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS, the operation completes asynchronously. Without crypto_wait_req(), the function immediately frees the request buffer, leading to crashes when the driver later accesses the freed memory. This results in a use-after-free condition when the hardware crypto driver later accesses the freed request structure, leading to kernel crashes with NULL pointer dereferences. The issue occurs because crypto_alloc_aead() with mask=0 doesn't guarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in the mask, async implementations can be selected. Fix by restoring the async crypto handling: - DECLARE_CRYPTO_WAIT(wait) for completion tracking - aead_request_set_callback() for async completion notification - crypto_wait_req() to wait for operation completion This ensures the request buffer isn't freed until the crypto operation completes, whether synchronous or asynchronous, while preserving the CVE-2024-50047 fix. Fixes: b0abcd65ec54 ("smb: client: fix UAF in async decryption") Link: https://lore.kernel.org/all/8b784a13-87b0-4131-9ff9-7a8993538749@huaweicloud.com/ Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Wang Zhaolong Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/smb2ops.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -4342,6 +4342,7 @@ crypt_message(struct TCP_Server_Info *se u8 key[SMB3_ENC_DEC_KEY_SIZE]; struct aead_request *req; u8 *iv; + DECLARE_CRYPTO_WAIT(wait); unsigned int crypt_len = le32_to_cpu(tr_hdr->OriginalMessageSize); void *creq; size_t sensitive_size; @@ -4392,7 +4393,11 @@ crypt_message(struct TCP_Server_Info *se aead_request_set_crypt(req, sg, sg, crypt_len, iv); aead_request_set_ad(req, assoc_data_len); - rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); + aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + crypto_req_done, &wait); + + rc = crypto_wait_req(enc ? crypto_aead_encrypt(req) + : crypto_aead_decrypt(req), &wait); if (!rc && enc) memcpy(&tr_hdr->Signature, sign, SMB2_SIGNATURE_SIZE);