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 --- drivers/bcma/scan.h | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 drivers/bcma/scan.h (limited to 'drivers/bcma/scan.h') diff --git a/drivers/bcma/scan.h b/drivers/bcma/scan.h new file mode 100644 index 000000000..e53079a3d --- /dev/null +++ b/drivers/bcma/scan.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BCMA_SCAN_H_ +#define BCMA_SCAN_H_ + +#define BCMA_ADDR_BASE 0x18000000 +#define BCMA_WRAP_BASE 0x18100000 + +#define SCAN_ER_VALID 0x00000001 +#define SCAN_ER_TAGX 0x00000006 /* we have to ignore 0x8 bit when checking tag for SCAN_ER_TAG_ADDR */ +#define SCAN_ER_TAG 0x0000000E +#define SCAN_ER_TAG_CI 0x00000000 +#define SCAN_ER_TAG_MP 0x00000002 +#define SCAN_ER_TAG_ADDR 0x00000004 +#define SCAN_ER_TAG_END 0x0000000E +#define SCAN_ER_BAD 0xFFFFFFFF + +#define SCAN_CIA_CLASS 0x000000F0 +#define SCAN_CIA_CLASS_SHIFT 4 +#define SCAN_CIA_ID 0x000FFF00 +#define SCAN_CIA_ID_SHIFT 8 +#define SCAN_CIA_MANUF 0xFFF00000 +#define SCAN_CIA_MANUF_SHIFT 20 + +#define SCAN_CIB_NMP 0x000001F0 +#define SCAN_CIB_NMP_SHIFT 4 +#define SCAN_CIB_NSP 0x00003E00 +#define SCAN_CIB_NSP_SHIFT 9 +#define SCAN_CIB_NMW 0x0007C000 +#define SCAN_CIB_NMW_SHIFT 14 +#define SCAN_CIB_NSW 0x00F80000 +#define SCAN_CIB_NSW_SHIFT 19 +#define SCAN_CIB_REV 0xFF000000 +#define SCAN_CIB_REV_SHIFT 24 + +#define SCAN_ADDR_AG32 0x00000008 +#define SCAN_ADDR_SZ 0x00000030 +#define SCAN_ADDR_SZ_SHIFT 4 +#define SCAN_ADDR_SZ_4K 0x00000000 +#define SCAN_ADDR_SZ_8K 0x00000010 +#define SCAN_ADDR_SZ_16K 0x00000020 +#define SCAN_ADDR_SZ_SZD 0x00000030 +#define SCAN_ADDR_TYPE 0x000000C0 +#define SCAN_ADDR_TYPE_SLAVE 0x00000000 +#define SCAN_ADDR_TYPE_BRIDGE 0x00000040 +#define SCAN_ADDR_TYPE_SWRAP 0x00000080 +#define SCAN_ADDR_TYPE_MWRAP 0x000000C0 +#define SCAN_ADDR_PORT 0x00000F00 +#define SCAN_ADDR_PORT_SHIFT 8 +#define SCAN_ADDR_ADDR 0xFFFFF000 + +#define SCAN_ADDR_SZ_BASE 0x00001000 /* 4KB */ + +#define SCAN_SIZE_SZ_ALIGN 0x00000FFF +#define SCAN_SIZE_SZ 0xFFFFF000 +#define SCAN_SIZE_SG32 0x00000008 + +#endif /* BCMA_SCAN_H_ */ -- cgit v1.3.1