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 --- include/media/jpeg.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 include/media/jpeg.h (limited to 'include/media/jpeg.h') diff --git a/include/media/jpeg.h b/include/media/jpeg.h new file mode 100644 index 000000000..a01e142e9 --- /dev/null +++ b/include/media/jpeg.h @@ -0,0 +1,20 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef _MEDIA_JPEG_H_ +#define _MEDIA_JPEG_H_ + +/* JPEG markers */ +#define JPEG_MARKER_TEM 0x01 +#define JPEG_MARKER_SOF0 0xc0 +#define JPEG_MARKER_DHT 0xc4 +#define JPEG_MARKER_RST 0xd0 +#define JPEG_MARKER_SOI 0xd8 +#define JPEG_MARKER_EOI 0xd9 +#define JPEG_MARKER_SOS 0xda +#define JPEG_MARKER_DQT 0xdb +#define JPEG_MARKER_DRI 0xdd +#define JPEG_MARKER_DHP 0xde +#define JPEG_MARKER_APP0 0xe0 +#define JPEG_MARKER_COM 0xfe + +#endif /* _MEDIA_JPEG_H_ */ -- cgit v1.3.1