Commit 4a1cc9e9 authored by Sudeep Holla's avatar Sudeep Holla
Browse files

firmware: arm_ffa: Validate framework notification message layout 

Framework notifications carry an indirect message in the shared RX
buffer. Validate the reported offset and size before using them, reject
zero-length payloads, and ensure that any non-header payload starts at
the UUID field rather than in the middle of the message header.

Use the validated offset and size values for both kmemdup() and the UUID
parsing path so malformed firmware data cannot drive an out-of-bounds
read or an oversized allocation.

Fixes: 285a5ea0 ("firmware: arm_ffa: Add support for handling framework notifications")
Link: https://patch.msgid.link/20260428-ffa_fixes-v2-8-8595ae450034@kernel.org


Signed-off-by: default avatarSudeep Holla <sudeep.holla@kernel.org>
parent 2af18f8e

drivers/firmware/arm_ffa/driver.c

+16 −2
Original line number Diff line number Diff line
@@ -1487,21 +1487,35 @@ static void handle_fwk_notif_callbacks(u32 bitmap) 
	int notify_id = 0, target;

	struct ffa_indirect_msg_hdr *msg;

	struct notifier_cb_info *cb_info = NULL;

	size_t min_offset = offsetof(struct ffa_indirect_msg_hdr, uuid);



	/* Only one framework notification defined and supported for now */

	if (!(bitmap & FRAMEWORK_NOTIFY_RX_BUFFER_FULL))

		return;



	scoped_guard(mutex, &drv_info->rx_lock) {

		u32 offset, size;



		msg = drv_info->rx_buffer;

		buf = kmemdup((void *)msg + msg->offset, msg->size, GFP_KERNEL);

		offset = msg->offset;

		size = msg->size;



		if (!size || (offset != min_offset && offset < sizeof(*msg)) ||

		    offset > drv_info->rxtx_bufsz ||

		    size > drv_info->rxtx_bufsz - offset) {

			pr_err("invalid framework notification message\n");

			ffa_rx_release();

			return;

		}



		buf = kmemdup((void *)msg + offset, size, GFP_KERNEL);

		if (!buf) {

			ffa_rx_release();

			return;

		}



		target = SENDER_ID(msg->send_recv_id);

		if (msg->offset >= sizeof(*msg))

		if (offset >= sizeof(*msg))

			uuid_copy(&uuid, &msg->uuid);

		else

			uuid_copy(&uuid, &uuid_null);