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 CE881433A8; Tue, 22 Jul 2025 13:47:20 +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=1753192041; cv=none; b=l3f6kdvP+sc5etAUmUsYoGX/L4N9D8uqCalNe47H7IGUz9CugPljzDHukFz1aIwLgfYIa12MAdXcMZIroamarhTHeHCqypoUFVoTTJNrY4HFzrGu4IZLPHQ6icB5AJ93Md7xoUH0UMd8pYDGlzl2UmqwKLUKSBmRsJTTNy+HVaU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753192041; c=relaxed/simple; bh=9bMIiWhLPqqJqjoC5NJ9QkaT0Gm84MgScawmQ/E0CMo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=quzCbEJRUKqbQIpZ09BpNNiXxL9qNI0iSD/kzWWPsKjuL2fQAHHuQv757gdc8xC8KNOLK30KAtM3ual59RWu0LoSJCXcAAYMbf0LTGlluOP1MmePAohOymuxS14wi/ECnpF0RdkteXhr2SXtaXTASi0U5aIsHSwFM8K+DyAw/HM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JqHXWan3; 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="JqHXWan3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7F57C4CEF6; Tue, 22 Jul 2025 13:47:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1753192040; bh=9bMIiWhLPqqJqjoC5NJ9QkaT0Gm84MgScawmQ/E0CMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JqHXWan3HBdNo0Tks3PO8MCE2ei8S6s2RV0FgXsLYUWnZ8eEEMlg87Nl+FGPh8Fs6 JbPST6VzQUgjnjIcR4Ar6lJ9m3jpVb4eP6YZ65ieGPjWvZcF387CjJ2rj4sXFQhXxb OI6oPbfsMZ2gh6k2zq+nqtWcB897YQUfQM+8OarE= 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 6.1 27/79] smb: client: fix use-after-free in crypt_message when using async crypto Date: Tue, 22 Jul 2025 15:44:23 +0200 Message-ID: <20250722134329.369300470@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250722134328.384139905@linuxfoundation.org> References: <20250722134328.384139905@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 6.1-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 @@ -4497,6 +4497,7 @@ 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; @@ -4545,7 +4546,11 @@ 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);