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 --- include/drm/drm_ras.h | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 include/drm/drm_ras.h (limited to 'include/drm/drm_ras.h') diff --git a/include/drm/drm_ras.h b/include/drm/drm_ras.h new file mode 100644 index 000000000..0beede3dd --- /dev/null +++ b/include/drm/drm_ras.h @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: MIT */ +/* + * Copyright © 2026 Intel Corporation + */ + +#ifndef __DRM_RAS_H__ +#define __DRM_RAS_H__ + +#include + +#include + +/** + * struct drm_ras_node - A DRM RAS Node + */ +struct drm_ras_node { + /** @id: Unique identifier for the node. Dynamically assigned. */ + u32 id; + /** + * @device_name: Human-readable name of the device. Given by the driver. + */ + const char *device_name; + /** @node_name: Human-readable name of the node. Given by the driver. */ + const char *node_name; + /** @type: Type of the node (enum drm_ras_node_type). */ + enum drm_ras_node_type type; + + /* Error-Counter Related Callback and Variables */ + + /** @error_counter_range: Range of valid Error IDs for this node. */ + struct { + /** @first: First valid Error ID. */ + u32 first; + /** @last: Last valid Error ID. Mandatory entry. */ + u32 last; + } error_counter_range; + + /** + * @query_error_counter: + * + * This callback is used by drm-ras to query a specific error counter. + * Used for input check and to iterate all error counters in a node. + * + * Driver should expect query_error_counter() to be called with + * error_id from `error_counter_range.first` to + * `error_counter_range.last`. + * + * The @query_error_counter is a mandatory callback for + * error_counter_node. + * + * Returns: 0 on success, + * -ENOENT when error_id is not supported as an indication that + * drm_ras should silently skip this entry. Used for + * supporting non-contiguous error ranges. + * Driver is responsible for maintaining the list of + * supported error IDs in the range of first to last. + * Other negative values on errors that should terminate the + * netlink query. + */ + int (*query_error_counter)(struct drm_ras_node *node, u32 error_id, + const char **name, u32 *val); + + /** + * @clear_error_counter: + * + * This callback is used by drm_ras to clear a specific error counter. + * Driver should implement this callback to support clearing error counters + * of a node. + * + * Returns: 0 on success, negative error code on failure. + */ + int (*clear_error_counter)(struct drm_ras_node *node, u32 error_id); + + /** @priv: Driver private data */ + void *priv; +}; + +struct drm_device; + +#if IS_ENABLED(CONFIG_DRM_RAS) +int drm_ras_node_register(struct drm_ras_node *node); +void drm_ras_node_unregister(struct drm_ras_node *node); +#else +static inline int drm_ras_node_register(struct drm_ras_node *node) { return 0; } +static inline void drm_ras_node_unregister(struct drm_ras_node *node) { } +#endif + +#endif -- cgit v1.3.1