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/vdso.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 tools/perf/util/vdso.h (limited to 'tools/perf/util/vdso.h') diff --git a/tools/perf/util/vdso.h b/tools/perf/util/vdso.h new file mode 100644 index 000000000..bc74ace60 --- /dev/null +++ b/tools/perf/util/vdso.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_VDSO__ +#define __PERF_VDSO__ + +#include +#include +#include + +#define VDSO__MAP_NAME "[vdso]" + +#define DSO__NAME_VDSO "[vdso]" +#define DSO__NAME_VDSO32 "[vdso32]" +#define DSO__NAME_VDSOX32 "[vdsox32]" + +static inline bool is_vdso_map(const char *filename) +{ + return !strcmp(filename, VDSO__MAP_NAME); +} + +struct dso; + +bool dso__is_vdso(struct dso *dso); + +struct machine; +struct thread; + +struct dso *machine__findnew_vdso(struct machine *machine, struct thread *thread); +void machine__exit_vdso(struct machine *machine); + +#endif /* __PERF_VDSO__ */ -- cgit v1.3.1