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/misc/altera.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/misc/altera.h (limited to 'include/misc/altera.h') diff --git a/include/misc/altera.h b/include/misc/altera.h new file mode 100644 index 000000000..60cb5c598 --- /dev/null +++ b/include/misc/altera.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * altera.h + * + * altera FPGA driver + * + * Copyright (C) Altera Corporation 1998-2001 + * Copyright (C) 2010 NetUP Inc. + * Copyright (C) 2010 Igor M. Liplianin + */ + +#ifndef _ALTERA_H_ +#define _ALTERA_H_ + +struct altera_config { + void *dev; + u8 *action; + int (*jtag_io) (void *dev, int tms, int tdi, int tdo); +}; + +#if defined(CONFIG_ALTERA_STAPL) || \ + (defined(CONFIG_ALTERA_STAPL_MODULE) && defined(MODULE)) + +extern int altera_init(struct altera_config *config, const struct firmware *fw); +#else + +static inline int altera_init(struct altera_config *config, + const struct firmware *fw) +{ + printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__); + return 0; +} +#endif /* CONFIG_ALTERA_STAPL */ + +#endif /* _ALTERA_H_ */ -- cgit v1.3.1