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/rds/info.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 net/rds/info.h (limited to 'net/rds/info.h') diff --git a/net/rds/info.h b/net/rds/info.h new file mode 100644 index 000000000..1aab62ab6 --- /dev/null +++ b/net/rds/info.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _RDS_INFO_H +#define _RDS_INFO_H + +struct rds_info_lengths { + unsigned int nr; + unsigned int each; +}; + +struct rds_info_iterator; + +/* + * These functions must fill in the fields of @lens to reflect the size + * of the available info source. If the snapshot fits in @len then it + * should be copied using @iter. The caller will deduce if it was copied + * or not by comparing the lengths. + */ +typedef void (*rds_info_func)(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens); + +void rds_info_register_func(int optname, rds_info_func func); +void rds_info_deregister_func(int optname, rds_info_func func); +int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt); +void rds_info_copy(struct rds_info_iterator *iter, void *data, + unsigned long bytes); +void rds_info_iter_unmap(struct rds_info_iterator *iter); + + +#endif -- cgit v1.3.1