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/genelf.h | 89 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 tools/perf/util/genelf.h (limited to 'tools/perf/util/genelf.h') diff --git a/tools/perf/util/genelf.h b/tools/perf/util/genelf.h new file mode 100644 index 000000000..9f0b875d6 --- /dev/null +++ b/tools/perf/util/genelf.h @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __GENELF_H__ +#define __GENELF_H__ + +#include + +/* genelf.c */ +int jit_write_elf(int fd, uint64_t code_addr, const char *sym, + const void *code, int csize, void *debug, int nr_debug_entries, + void *unwinding, uint64_t unwinding_header_size, uint64_t unwinding_size); +#ifdef HAVE_LIBDW_SUPPORT +/* genelf_debug.c */ +int jit_add_debug_info(Elf *e, uint64_t code_addr, void *debug, int nr_debug_entries); +#endif + +#if defined(__arm__) +#define GEN_ELF_ARCH EM_ARM +#define GEN_ELF_CLASS ELFCLASS32 +#elif defined(__aarch64__) +#define GEN_ELF_ARCH EM_AARCH64 +#define GEN_ELF_CLASS ELFCLASS64 +#elif defined(__x86_64__) +#define GEN_ELF_ARCH EM_X86_64 +#define GEN_ELF_CLASS ELFCLASS64 +#elif defined(__i386__) +#define GEN_ELF_ARCH EM_386 +#define GEN_ELF_CLASS ELFCLASS32 +#elif defined(__powerpc64__) +#define GEN_ELF_ARCH EM_PPC64 +#define GEN_ELF_CLASS ELFCLASS64 +#elif defined(__powerpc__) +#define GEN_ELF_ARCH EM_PPC +#define GEN_ELF_CLASS ELFCLASS32 +#elif defined(__sparc__) && defined(__arch64__) +#define GEN_ELF_ARCH EM_SPARCV9 +#define GEN_ELF_CLASS ELFCLASS64 +#elif defined(__sparc__) +#define GEN_ELF_ARCH EM_SPARC +#define GEN_ELF_CLASS ELFCLASS32 +#elif defined(__s390x__) +#define GEN_ELF_ARCH EM_S390 +#define GEN_ELF_CLASS ELFCLASS64 +#elif defined(__riscv) && __riscv_xlen == 64 +#define GEN_ELF_ARCH EM_RISCV +#define GEN_ELF_CLASS ELFCLASS64 +#elif defined(__riscv) && __riscv_xlen == 32 +#define GEN_ELF_ARCH EM_RISCV +#define GEN_ELF_CLASS ELFCLASS32 +#elif defined(__loongarch__) +#define GEN_ELF_ARCH EM_LOONGARCH +#define GEN_ELF_CLASS ELFCLASS64 +#else +#error "unsupported architecture" +#endif + +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ +#define GEN_ELF_ENDIAN ELFDATA2MSB +#else +#define GEN_ELF_ENDIAN ELFDATA2LSB +#endif + +#if GEN_ELF_CLASS == ELFCLASS64 +#define elf_newehdr elf64_newehdr +#define elf_newphdr elf64_newphdr +#define elf_getshdr elf64_getshdr +#define Elf_Ehdr Elf64_Ehdr +#define Elf_Phdr Elf64_Phdr +#define Elf_Shdr Elf64_Shdr +#define Elf_Sym Elf64_Sym +#define ELF_ST_TYPE(a) ELF64_ST_TYPE(a) +#define ELF_ST_BIND(a) ELF64_ST_BIND(a) +#define ELF_ST_VIS(a) ELF64_ST_VISIBILITY(a) +#else +#define elf_newehdr elf32_newehdr +#define elf_newphdr elf32_newphdr +#define elf_getshdr elf32_getshdr +#define Elf_Ehdr Elf32_Ehdr +#define Elf_Phdr Elf32_Phdr +#define Elf_Shdr Elf32_Shdr +#define Elf_Sym Elf32_Sym +#define ELF_ST_TYPE(a) ELF32_ST_TYPE(a) +#define ELF_ST_BIND(a) ELF32_ST_BIND(a) +#define ELF_ST_VIS(a) ELF32_ST_VISIBILITY(a) +#endif + +/* The .text section is directly after the ELF header */ +#define GEN_ELF_TEXT_OFFSET round_up(sizeof(Elf_Ehdr) + sizeof(Elf_Phdr), 16) + +#endif -- cgit v1.3.1