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/bpf-event.h | 73 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 tools/perf/util/bpf-event.h (limited to 'tools/perf/util/bpf-event.h') diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h new file mode 100644 index 000000000..da4eeb4a1 --- /dev/null +++ b/tools/perf/util/bpf-event.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_BPF_EVENT_H +#define __PERF_BPF_EVENT_H + +#include +#include +#include +#include + +struct bpf_prog_info; +struct machine; +union perf_event; +struct perf_env; +struct perf_sample; +struct perf_session; +struct record_opts; +struct evlist; +struct target; + +struct bpf_metadata { + union perf_event *event; + char **prog_names; + __u64 nr_prog_names; +}; + +struct bpf_prog_info_node { + struct perf_bpil *info_linear; + struct bpf_metadata *metadata; + struct rb_node rb_node; +}; + +struct btf_node { + struct rb_node rb_node; + u32 id; + u32 data_size; + char data[]; +}; + +#ifdef HAVE_LIBBPF_SUPPORT +int machine__process_bpf(struct machine *machine, union perf_event *event, + struct perf_sample *sample); +int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env); +void __bpf_event__print_bpf_prog_info(struct perf_bpil *info_linear, + struct perf_env *env, + FILE *fp); +void bpf_metadata_free(struct bpf_metadata *metadata); +#else +static inline int machine__process_bpf(struct machine *machine __maybe_unused, + union perf_event *event __maybe_unused, + struct perf_sample *sample __maybe_unused) +{ + return 0; +} + +static inline int evlist__add_bpf_sb_event(struct evlist *evlist __maybe_unused, + struct perf_env *env __maybe_unused) +{ + return 0; +} + +static inline void __bpf_event__print_bpf_prog_info(struct perf_bpil *info_linear __maybe_unused, + struct perf_env *env __maybe_unused, + FILE *fp __maybe_unused) +{ + +} + +static inline void bpf_metadata_free(struct bpf_metadata *metadata __maybe_unused) +{ + +} +#endif // HAVE_LIBBPF_SUPPORT +#endif -- cgit v1.3.1