From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- drivers/firmware/imx/rm.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/firmware/imx/rm.c (limited to 'drivers/firmware/imx/rm.c') diff --git a/drivers/firmware/imx/rm.c b/drivers/firmware/imx/rm.c new file mode 100644 index 000000000..d492b99e1 --- /dev/null +++ b/drivers/firmware/imx/rm.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2020 NXP + * + * File containing client-side RPC functions for the RM service. These + * function are ported to clients that communicate to the SC. + */ + +#include + +struct imx_sc_msg_rm_rsrc_owned { + struct imx_sc_rpc_msg hdr; + u16 resource; +} __packed __aligned(4); + +/* + * This function check @resource is owned by current partition or not + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * + * @return Returns 0 for not owned and 1 for owned. + */ +bool imx_sc_rm_is_resource_owned(struct imx_sc_ipc *ipc, u16 resource) +{ + struct imx_sc_msg_rm_rsrc_owned msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_RM; + hdr->func = IMX_SC_RM_FUNC_IS_RESOURCE_OWNED; + hdr->size = 2; + + msg.resource = resource; + + /* + * SCU firmware only returns value 0 or 1 + * for resource owned check which means not owned or owned. + * So it is always successful. + */ + imx_scu_call_rpc(ipc, &msg, true); + + return hdr->func; +} +EXPORT_SYMBOL(imx_sc_rm_is_resource_owned); + +struct imx_sc_msg_rm_get_resource_owner { + struct imx_sc_rpc_msg hdr; + union { + struct { + u16 resource; + } req; + struct { + u8 val; + } resp; + } data; +} __packed __aligned(4); + +/* + * This function get @resource partition number + * + * @param[in] ipc IPC handle + * @param[in] resource resource the control is associated with + * @param[out] pt pointer to return the partition number + * + * @return Returns 0 for success and < 0 for errors. + */ +int imx_sc_rm_get_resource_owner(struct imx_sc_ipc *ipc, u16 resource, u8 *pt) +{ + struct imx_sc_msg_rm_get_resource_owner msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + int ret; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_RM; + hdr->func = IMX_SC_RM_FUNC_GET_RESOURCE_OWNER; + hdr->size = 2; + + msg.data.req.resource = resource; + + ret = imx_scu_call_rpc(ipc, &msg, true); + if (ret) + return ret; + + if (pt) + *pt = msg.data.resp.val; + + return 0; +} +EXPORT_SYMBOL(imx_sc_rm_get_resource_owner); -- cgit v1.3.1