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/mmap.h | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 tools/perf/util/mmap.h (limited to 'tools/perf/util/mmap.h') diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h new file mode 100644 index 000000000..4d72c5fa5 --- /dev/null +++ b/tools/perf/util/mmap.h @@ -0,0 +1,64 @@ +#ifndef __PERF_MMAP_H +#define __PERF_MMAP_H 1 + +#include +#include +#include +#include +#ifdef HAVE_AIO_SUPPORT +#include +#endif +#include "auxtrace.h" +#include "util/compress.h" + +struct aiocb; + +struct mmap_cpu_mask { + unsigned long *bits; + size_t nbits; +}; + +#define MMAP_CPU_MASK_BYTES(m) \ + (BITS_TO_LONGS(((struct mmap_cpu_mask *)m)->nbits) * sizeof(unsigned long)) + +/** + * struct mmap - perf's ring buffer mmap details + * + * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this + */ +struct mmap { + struct perf_mmap core; + struct auxtrace_mmap auxtrace_mmap; +#ifdef HAVE_AIO_SUPPORT + struct { + void **data; + struct aiocb *cblocks; + struct aiocb **aiocb; + int nr_cblocks; + } aio; +#endif + struct mmap_cpu_mask affinity_mask; + void *data; + struct perf_data_file *file; + struct zstd_data zstd_data; +}; + +struct mmap_params { + struct perf_mmap_param core; + int nr_cblocks, affinity, flush, comp_level; + struct auxtrace_mmap_params auxtrace_mp; +}; + +int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, struct perf_cpu cpu); +void mmap__munmap(struct mmap *map); + +union perf_event *perf_mmap__read_forward(struct mmap *map); + +int perf_mmap__push(struct mmap *md, void *to, + int push(struct mmap *map, void *to, void *buf, size_t size)); + +size_t mmap__mmap_len(struct mmap *map); + +void mmap_cpu_mask__scnprintf(struct mmap_cpu_mask *mask, const char *tag); + +#endif /*__PERF_MMAP_H */ -- cgit v1.3.1