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/ipack/devices/ipoctal.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 drivers/ipack/devices/ipoctal.h (limited to 'drivers/ipack/devices/ipoctal.h') diff --git a/drivers/ipack/devices/ipoctal.h b/drivers/ipack/devices/ipoctal.h new file mode 100644 index 000000000..773dc41bd --- /dev/null +++ b/drivers/ipack/devices/ipoctal.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * driver for the IPOCTAL boards + * + * Copyright (C) 2009-2012 CERN (www.cern.ch) + * Author: Nicolas Serafini, EIC2 SA + * Author: Samuel Iglesias Gonsalvez + */ + +#ifndef _IPOCTAL_H_ +#define _IPOCTAL_H_ + +#define NR_CHANNELS 8 +#define IPOCTAL_MAX_BOARDS 16 +#define MAX_DEVICES (NR_CHANNELS * IPOCTAL_MAX_BOARDS) + +/** + * struct ipoctal_stats -- Stats since last reset + * + * @tx: Number of transmitted bytes + * @rx: Number of received bytes + * @overrun: Number of overrun errors + * @parity_err: Number of parity errors + * @framing_err: Number of framing errors + * @rcv_break: Number of break received + */ +struct ipoctal_stats { + unsigned long tx; + unsigned long rx; + unsigned long overrun_err; + unsigned long parity_err; + unsigned long framing_err; + unsigned long rcv_break; +}; + +#endif /* _IPOCTAL_H_ */ -- cgit v1.3.1