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/tests/pe-file.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 tools/perf/tests/pe-file.c (limited to 'tools/perf/tests/pe-file.c') diff --git a/tools/perf/tests/pe-file.c b/tools/perf/tests/pe-file.c new file mode 100644 index 000000000..eb3df5e98 --- /dev/null +++ b/tools/perf/tests/pe-file.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0 + +// pe-file.exe and pe-file.exe.debug built with; +// x86_64-w64-mingw32-gcc -o pe-file.exe pe-file.c +// -Wl,--file-alignment,4096 -Wl,--build-id +// x86_64-w64-mingw32-objcopy --only-keep-debug +// --compress-debug-sections pe-file.exe pe-file.exe.debug +// x86_64-w64-mingw32-objcopy --strip-debug +// --add-gnu-debuglink=pe-file.exe.debug pe-file.exe + +int main(int argc, char const *argv[]) +{ + return 0; +} -- cgit v1.3.1