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 --- net/atm/resources.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 net/atm/resources.h (limited to 'net/atm/resources.h') diff --git a/net/atm/resources.h b/net/atm/resources.h new file mode 100644 index 000000000..4a0839e92 --- /dev/null +++ b/net/atm/resources.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* net/atm/resources.h - ATM-related resources */ + +/* Written 1995-1998 by Werner Almesberger, EPFL LRC/ICA */ + + +#ifndef NET_ATM_RESOURCES_H +#define NET_ATM_RESOURCES_H + +#include +#include + + +extern struct list_head atm_devs; +extern struct mutex atm_dev_mutex; + +int atm_getnames(void __user *buf, int __user *iobuf_len); +int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len, + int number, int compat); + +#ifdef CONFIG_PROC_FS + +#include + +void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos); +void atm_dev_seq_stop(struct seq_file *seq, void *v); +void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos); + + +int atm_proc_dev_register(struct atm_dev *dev); +void atm_proc_dev_deregister(struct atm_dev *dev); + +#else + +static inline int atm_proc_dev_register(struct atm_dev *dev) +{ + return 0; +} + +static inline void atm_proc_dev_deregister(struct atm_dev *dev) +{ + /* nothing */ +} + +#endif /* CONFIG_PROC_FS */ + +int atm_register_sysfs(struct atm_dev *adev, struct device *parent); +void atm_unregister_sysfs(struct atm_dev *adev); +#endif -- cgit v1.3.1