queue-6.18/accel-amdxdna-fix-potential-null-pointer-dereference.patch

From 57afb3ef9c61992e6f30ff32e1d1e9452cff354f Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Fri, 12 Dec 2025 10:32:44 -0800
Subject: accel/amdxdna: Fix potential NULL pointer dereference in context
 cleanup

From: Lizhi Hou <lizhi.hou@amd.com>

[ Upstream commit 97f27573837ef96b4ba42af463cc800cab615c0e ]

aie_destroy_context() is invoked during error handling in
aie2_create_context(). However, aie_destroy_context() assumes that the
context's mailbox channel pointer is non-NULL. If mailbox channel
creation fails, the pointer remains NULL and calling aie_destroy_context()
can lead to a NULL pointer dereference.

In aie2_create_context(), replace aie_destroy_context() with a function
which request firmware to remove the context created previously.

Fixes: be462c97b7df ("accel/amdxdna: Add hardware context")
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20251212183244.1826318-1-lizhi.hou@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/accel/amdxdna/aie2_message.c | 46 ++++++++++++++++------------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/drivers/accel/amdxdna/aie2_message.c b/drivers/accel/amdxdna/aie2_message.c
index 4660e8297ed80..932d495230511 100644
--- a/drivers/accel/amdxdna/aie2_message.c
+++ b/drivers/accel/amdxdna/aie2_message.c
@@ -184,6 +184,19 @@ int aie2_query_firmware_version(struct amdxdna_dev_hdl *ndev,
 	return 0;
 }
 
+static int aie2_destroy_context_req(struct amdxdna_dev_hdl *ndev, u32 id)
+{
+	DECLARE_AIE2_MSG(destroy_ctx, MSG_OP_DESTROY_CONTEXT);
+	struct amdxdna_dev *xdna = ndev->xdna;
+	int ret;
+
+	req.context_id = id;
+	ret = aie2_send_mgmt_msg_wait(ndev, &msg);
+	if (ret)
+		XDNA_WARN(xdna, "Destroy context failed, ret %d", ret);
+
+	return ret;
+}
 int aie2_create_context(struct amdxdna_dev_hdl *ndev, struct amdxdna_hwctx *hwctx)
 {
 	DECLARE_AIE2_MSG(create_ctx, MSG_OP_CREATE_CONTEXT);
@@ -206,7 +219,8 @@ int aie2_create_context(struct amdxdna_dev_hdl *ndev, struct amdxdna_hwctx *hwct
 		return ret;
 
 	hwctx->fw_ctx_id = resp.context_id;
-	WARN_ONCE(hwctx->fw_ctx_id == -1, "Unexpected context id");
+	if (WARN_ON_ONCE(hwctx->fw_ctx_id == -1))
+		return -EINVAL;
 
 	cq_pair = &resp.cq_pair[0];
 	x2i.mb_head_ptr_reg = AIE2_MBOX_OFF(ndev, cq_pair->x2i_q.head_addr);
@@ -221,34 +235,32 @@ int aie2_create_context(struct amdxdna_dev_hdl *ndev, struct amdxdna_hwctx *hwct
 
 	ret = pci_irq_vector(to_pci_dev(xdna->ddev.dev), resp.msix_id);
 	if (ret == -EINVAL) {
-		XDNA_ERR(xdna, "not able to create channel");
-		goto out_destroy_context;
+		XDNA_ERR(xdna, "Alloc IRQ failed %d", ret);
+		goto del_ctx_req;
 	}
 
 	intr_reg = i2x.mb_head_ptr_reg + 4;
 	hwctx->priv->mbox_chann = xdna_mailbox_create_channel(ndev->mbox, &x2i, &i2x,
 							      intr_reg, ret);
 	if (!hwctx->priv->mbox_chann) {
-		XDNA_ERR(xdna, "not able to create channel");
+		XDNA_ERR(xdna, "Not able to create channel");
 		ret = -EINVAL;
-		goto out_destroy_context;
+		goto del_ctx_req;
 	}
 
-	XDNA_DBG(xdna, "%s mailbox channel irq: %d, msix_id: %d",
-		 hwctx->name, ret, resp.msix_id);
-	XDNA_DBG(xdna, "%s created fw ctx %d pasid %d", hwctx->name,
-		 hwctx->fw_ctx_id, hwctx->client->pasid);
+	XDNA_DBG(xdna, "Mailbox channel irq: %d, msix_id: %d", ret, resp.msix_id);
+	XDNA_DBG(xdna, "Created fw ctx %d pasid %d", hwctx->fw_ctx_id, hwctx->client->pasid);
 
 	return 0;
 
-out_destroy_context:
-	aie2_destroy_context(ndev, hwctx);
+del_ctx_req:
+	aie2_destroy_context_req(ndev, hwctx->fw_ctx_id);
+	hwctx->fw_ctx_id = -1;
 	return ret;
 }
 
 int aie2_destroy_context(struct amdxdna_dev_hdl *ndev, struct amdxdna_hwctx *hwctx)
 {
-	DECLARE_AIE2_MSG(destroy_ctx, MSG_OP_DESTROY_CONTEXT);
 	struct amdxdna_dev *xdna = ndev->xdna;
 	int ret;
 
@@ -256,15 +268,9 @@ int aie2_destroy_context(struct amdxdna_dev_hdl *ndev, struct amdxdna_hwctx *hwc
 		return 0;
 
 	xdna_mailbox_stop_channel(hwctx->priv->mbox_chann);
-
-	req.context_id = hwctx->fw_ctx_id;
-	ret = aie2_send_mgmt_msg_wait(ndev, &msg);
-	if (ret)
-		XDNA_WARN(xdna, "%s destroy context failed, ret %d", hwctx->name, ret);
-
+	ret = aie2_destroy_context_req(ndev, hwctx->fw_ctx_id);
 	xdna_mailbox_destroy_channel(hwctx->priv->mbox_chann);
-	XDNA_DBG(xdna, "%s destroyed fw ctx %d", hwctx->name,
-		 hwctx->fw_ctx_id);
+	XDNA_DBG(xdna, "Destroyed fw ctx %d", hwctx->fw_ctx_id);
 	hwctx->priv->mbox_chann = NULL;
 	hwctx->fw_ctx_id = -1;
 
-- 
2.53.0