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/zlib.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 tools/perf/util/zlib.c (limited to 'tools/perf/util/zlib.c') diff --git a/tools/perf/util/zlib.c b/tools/perf/util/zlib.c new file mode 100644 index 000000000..1f7c06523 --- /dev/null +++ b/tools/perf/util/zlib.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "util/compress.h" + +#define CHUNK_SIZE 16384 + +int gzip_decompress_to_file(const char *input, int output_fd) +{ + int ret = Z_STREAM_ERROR; + int input_fd; + void *ptr; + int len; + struct stat stbuf; + unsigned char buf[CHUNK_SIZE]; + z_stream zs = { + .zalloc = Z_NULL, + .zfree = Z_NULL, + .opaque = Z_NULL, + .avail_in = 0, + .next_in = Z_NULL, + }; + + input_fd = open(input, O_RDONLY); + if (input_fd < 0) + return -1; + + if (fstat(input_fd, &stbuf) < 0) + goto out_close; + + ptr = mmap(NULL, stbuf.st_size, PROT_READ, MAP_PRIVATE, input_fd, 0); + if (ptr == MAP_FAILED) + goto out_close; + + if (inflateInit2(&zs, 16 + MAX_WBITS) != Z_OK) + goto out_unmap; + + zs.next_in = ptr; + zs.avail_in = stbuf.st_size; + + do { + zs.next_out = buf; + zs.avail_out = CHUNK_SIZE; + + ret = inflate(&zs, Z_NO_FLUSH); + switch (ret) { + case Z_NEED_DICT: + ret = Z_DATA_ERROR; + /* fall through */ + case Z_DATA_ERROR: + case Z_MEM_ERROR: + goto out; + default: + break; + } + + len = CHUNK_SIZE - zs.avail_out; + if (writen(output_fd, buf, len) != len) { + ret = Z_DATA_ERROR; + goto out; + } + + } while (ret != Z_STREAM_END); + +out: + inflateEnd(&zs); +out_unmap: + munmap(ptr, stbuf.st_size); +out_close: + close(input_fd); + + return ret == Z_STREAM_END ? 0 : -1; +} + +bool gzip_is_compressed(const char *input) +{ + int fd = open(input, O_RDONLY); + const uint8_t magic[2] = { 0x1f, 0x8b }; + char buf[2] = { 0 }; + ssize_t rc; + + if (fd < 0) + return false; + + rc = read(fd, buf, sizeof(buf)); + close(fd); + return rc == sizeof(buf) ? + memcmp(buf, magic, sizeof(buf)) == 0 : false; +} -- cgit v1.3.1