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 --- tools/perf/util/expr.h | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 tools/perf/util/expr.h (limited to 'tools/perf/util/expr.h') diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h new file mode 100644 index 000000000..ed12e4007 --- /dev/null +++ b/tools/perf/util/expr.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef PARSE_CTX_H +#define PARSE_CTX_H 1 + +struct hashmap; +struct metric_ref; + +struct expr_scanner_ctx { + char *user_requested_cpu_list; + int runtime; + bool system_wide; + bool is_test; +}; + +struct expr_parse_ctx { + struct hashmap *ids; + struct expr_scanner_ctx sctx; +}; + +struct expr_id_data; + +struct hashmap *ids__new(void); +void ids__free(struct hashmap *ids); +int ids__insert(struct hashmap *ids, const char *id); +/* + * Union two sets of ids (hashmaps) and construct a third, freeing ids1 and + * ids2. + */ +struct hashmap *ids__union(struct hashmap *ids1, struct hashmap *ids2); + +struct expr_parse_ctx *expr__ctx_new(void); +void expr__ctx_clear(struct expr_parse_ctx *ctx); +void expr__ctx_free(struct expr_parse_ctx *ctx); + +void expr__del_id(struct expr_parse_ctx *ctx, const char *id); +int expr__add_id(struct expr_parse_ctx *ctx, const char *id); +int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val); +int expr__add_id_val_source_count(struct expr_parse_ctx *ctx, const char *id, + double val, int source_count); +int expr__add_id_val_source_count_aggr_nr(struct expr_parse_ctx *ctx, const char *id, + double val, int source_count, int aggr_nr); +int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref); +int expr__get_id(struct expr_parse_ctx *ctx, const char *id, + struct expr_id_data **data); +bool expr__subset_of_ids(struct expr_parse_ctx *haystack, + struct expr_parse_ctx *needles); +int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id, + struct expr_id_data **datap); + +int expr__parse(double *final_val, struct expr_parse_ctx *ctx, + const char *expr); + +int expr__find_ids(const char *expr, const char *one, + struct expr_parse_ctx *ids); + +double expr_id_data__value(const struct expr_id_data *data); +double expr_id_data__source_count(const struct expr_id_data *data); +double expr_id_data__aggr_nr(const struct expr_id_data *data); + +double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx); +double expr__has_event(const struct expr_parse_ctx *ctx, bool compute_ids, const char *id); +double expr__strcmp_cpuid_str(const struct expr_parse_ctx *ctx, bool compute_ids, const char *id); + +#endif -- cgit v1.3.1