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/target.h | 98 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 tools/perf/util/target.h (limited to 'tools/perf/util/target.h') diff --git a/tools/perf/util/target.h b/tools/perf/util/target.h new file mode 100644 index 000000000..bc2bff9c6 --- /dev/null +++ b/tools/perf/util/target.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _PERF_TARGET_H +#define _PERF_TARGET_H + +#include +#include + +struct target { + const char *pid; + const char *tid; + const char *cpu_list; + const char *bpf_str; + bool system_wide; + bool uses_mmap; + bool default_per_cpu; + bool per_thread; + bool use_bpf; + bool inherit; + int initial_delay; + const char *attr_map; +}; + +enum target_errno { + TARGET_ERRNO__SUCCESS = 0, + + /* + * Choose an arbitrary negative big number not to clash with standard + * errno since SUS requires the errno has distinct positive values. + * See 'Issue 6' in the link below. + * + * http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html + */ + __TARGET_ERRNO__START = -10000, + + /* for target__validate() */ + TARGET_ERRNO__PID_OVERRIDE_CPU = __TARGET_ERRNO__START, + TARGET_ERRNO__PID_OVERRIDE_SYSTEM, + TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD, + TARGET_ERRNO__BPF_OVERRIDE_CPU, + TARGET_ERRNO__BPF_OVERRIDE_PID, + TARGET_ERRNO__BPF_OVERRIDE_THREAD, + + __TARGET_ERRNO__END, +}; + +enum target_errno target__validate(struct target *target); + +uid_t parse_uid(const char *str); + +int target__strerror(struct target *target, int errnum, char *buf, size_t buflen); + +static inline bool target__has_task(const struct target *target) +{ + return target->tid || target->pid; +} + +static inline bool target__has_cpu(const struct target *target) +{ + return target->system_wide || target->cpu_list; +} + +static inline bool target__none(const struct target *target) +{ + return !target__has_task(target) && !target__has_cpu(target); +} + +static inline bool target__enable_on_exec(const struct target *target) +{ + /* + * Normally enable_on_exec should be set if: + * 1) The tracee process is forked (not attaching to existed task or cpu). + * 2) And initial_delay is not configured. + * Otherwise, we enable tracee events manually. + */ + return target__none(target) && !target->initial_delay; +} + +static inline bool target__has_per_thread(const struct target *target) +{ + return target->system_wide && target->per_thread; +} + +static inline bool target__uses_dummy_map(const struct target *target) +{ + bool use_dummy = false; + + if (target->default_per_cpu) + use_dummy = target->per_thread ? true : false; + else if (target__has_task(target) || + (!target__has_cpu(target) && !target->uses_mmap)) + use_dummy = true; + else if (target__has_per_thread(target)) + use_dummy = true; + + return use_dummy; +} + +#endif /* _PERF_TARGET_H */ -- cgit v1.3.1