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 285A0339BE; Fri, 24 Nov 2023 19:09:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XB2oLItN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A448FC433C7; Fri, 24 Nov 2023 19:09:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700852955; bh=4b7oLvwhNkMrNflgbOkrlxpt8O+gmbO2AHpGTwgeJao=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XB2oLItNgfgqGq4OSBtQI3H0W9Bq9+V+swvMcxdSUv+EJqvkTD9dWq96qtgx+r3c1 VHCMbkps2zixSS3J82SbW8vODTa52tBfmuCditCv3h97r5tlrRUAUTM9m+zVIDNmBr MgBCwpAgqJEKhWYdvyiD0mUZ5JMe2uyeF+Vm61jU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Aneesh Kumar K.V" , Mahesh Salgaonkar , Michael Ellerman Subject: [PATCH 5.10 189/193] powerpc/powernv: Fix fortify source warnings in opal-prd.c Date: Fri, 24 Nov 2023 17:55:16 +0000 Message-ID: <20231124171954.750733172@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124171947.127438872@linuxfoundation.org> References: <20231124171947.127438872@linuxfoundation.org> User-Agent: quilt/0.67 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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Ellerman commit feea65a338e52297b68ceb688eaf0ffc50310a83 upstream. As reported by Mahesh & Aneesh, opal_prd_msg_notifier() triggers a FORTIFY_SOURCE warning: memcpy: detected field-spanning write (size 32) of single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size 4) WARNING: CPU: 9 PID: 660 at arch/powerpc/platforms/powernv/opal-prd.c:355 opal_prd_msg_notifier+0x174/0x188 [opal_prd] NIP opal_prd_msg_notifier+0x174/0x188 [opal_prd] LR opal_prd_msg_notifier+0x170/0x188 [opal_prd] Call Trace: opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable) notifier_call_chain+0xc0/0x1b0 atomic_notifier_call_chain+0x2c/0x40 opal_message_notify+0xf4/0x2c0 This happens because the copy is targeting item->msg, which is only 4 bytes in size, even though the enclosing item was allocated with extra space following the msg. To fix the warning define struct opal_prd_msg with a union of the header and a flex array, and have the memcpy target the flex array. Reported-by: "Aneesh Kumar K.V" Reported-by: Mahesh Salgaonkar Tested-by: Mahesh Salgaonkar Reviewed-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman Link: https://msgid.link/20230821142820.497107-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/opal-prd.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/arch/powerpc/platforms/powernv/opal-prd.c +++ b/arch/powerpc/platforms/powernv/opal-prd.c @@ -24,13 +24,20 @@ #include +struct opal_prd_msg { + union { + struct opal_prd_msg_header header; + DECLARE_FLEX_ARRAY(u8, data); + }; +}; + /* * The msg member must be at the end of the struct, as it's followed by the * message data. */ struct opal_prd_msg_queue_item { - struct list_head list; - struct opal_prd_msg_header msg; + struct list_head list; + struct opal_prd_msg msg; }; static struct device_node *prd_node; @@ -159,7 +166,7 @@ static ssize_t opal_prd_read(struct file int rc; /* we need at least a header's worth of data */ - if (count < sizeof(item->msg)) + if (count < sizeof(item->msg.header)) return -EINVAL; if (*ppos) @@ -189,7 +196,7 @@ static ssize_t opal_prd_read(struct file return -EINTR; } - size = be16_to_cpu(item->msg.size); + size = be16_to_cpu(item->msg.header.size); if (size > count) { err = -EINVAL; goto err_requeue; @@ -355,7 +362,7 @@ static int opal_prd_msg_notifier(struct if (!item) return -ENOMEM; - memcpy(&item->msg, msg->params, msg_size); + memcpy(&item->msg.data, msg->params, msg_size); spin_lock_irqsave(&opal_prd_msg_queue_lock, flags); list_add_tail(&item->list, &opal_prd_msg_queue);