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 --- fs/btrfs/async-thread.h | 51 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 fs/btrfs/async-thread.h (limited to 'fs/btrfs/async-thread.h') diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h new file mode 100644 index 000000000..04c2f3175 --- /dev/null +++ b/fs/btrfs/async-thread.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * Copyright (C) 2014 Fujitsu. All rights reserved. + */ + +#ifndef BTRFS_ASYNC_THREAD_H +#define BTRFS_ASYNC_THREAD_H + +#include +#include +#include + +struct btrfs_fs_info; +struct btrfs_workqueue; +struct btrfs_work; + +typedef void (*btrfs_func_t)(struct btrfs_work *arg); +typedef void (*btrfs_ordered_func_t)(struct btrfs_work *arg, bool); + +struct btrfs_work { + btrfs_func_t func; + btrfs_ordered_func_t ordered_func; + + /* Don't touch things below */ + struct work_struct normal_work; + struct list_head ordered_list; + struct btrfs_workqueue *wq; + unsigned long flags; +}; + +struct btrfs_workqueue *btrfs_alloc_workqueue(struct btrfs_fs_info *fs_info, + const char *name, + unsigned int flags, + int limit_active, + int thresh); +struct btrfs_workqueue *btrfs_alloc_ordered_workqueue( + struct btrfs_fs_info *fs_info, const char *name, + unsigned int flags); +void btrfs_init_work(struct btrfs_work *work, btrfs_func_t func, + btrfs_ordered_func_t ordered_func); +void btrfs_queue_work(struct btrfs_workqueue *wq, + struct btrfs_work *work); +void btrfs_destroy_workqueue(struct btrfs_workqueue *wq); +void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int max); +struct btrfs_fs_info * __pure btrfs_work_owner(const struct btrfs_work *work); +struct btrfs_fs_info * __pure btrfs_workqueue_owner(const struct btrfs_workqueue *wq); +bool btrfs_workqueue_normal_congested(const struct btrfs_workqueue *wq); +void btrfs_flush_workqueue(struct btrfs_workqueue *wq); + +#endif -- cgit v1.3.1