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/parse-sublevel-options.c | 70 ++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 tools/perf/util/parse-sublevel-options.c (limited to 'tools/perf/util/parse-sublevel-options.c') diff --git a/tools/perf/util/parse-sublevel-options.c b/tools/perf/util/parse-sublevel-options.c new file mode 100644 index 000000000..a841d17ff --- /dev/null +++ b/tools/perf/util/parse-sublevel-options.c @@ -0,0 +1,70 @@ +#include +#include +#include +#include + +#include "util/debug.h" +#include "util/parse-sublevel-options.h" + +static int parse_one_sublevel_option(const char *str, + struct sublevel_option *opts) +{ + struct sublevel_option *opt = opts; + char *vstr, *s = strdup(str); + int v = 1; + + if (!s) { + pr_err("no memory\n"); + return -1; + } + + vstr = strchr(s, '='); + if (vstr) + *vstr++ = 0; + + while (opt->name) { + if (!strcmp(s, opt->name)) + break; + opt++; + } + + if (!opt->name) { + pr_err("Unknown option name '%s'\n", s); + free(s); + return -1; + } + + if (vstr) + v = atoi(vstr); + + *opt->value_ptr = v; + free(s); + return 0; +} + +/* parse options like --foo a=,b,c... */ +int perf_parse_sublevel_options(const char *str, struct sublevel_option *opts) +{ + char *s = strdup(str); + char *p = NULL; + int ret; + + if (!s) { + pr_err("no memory\n"); + return -1; + } + + p = strtok(s, ","); + while (p) { + ret = parse_one_sublevel_option(p, opts); + if (ret) { + free(s); + return ret; + } + + p = strtok(NULL, ","); + } + + free(s); + return 0; +} -- cgit v1.3.1