linux_dsm_epyc7002/drivers/android/binder_alloc.h
Todd Kjos bb4a2e48d5 binder: return errors from buffer copy functions
The buffer copy functions assumed the caller would ensure
correct alignment and that the memory to be copied was
completely within the binder buffer. There have been
a few cases discovered by syzkallar where a malformed
transaction created by a user could violated the
assumptions and resulted in a BUG_ON.

The fix is to remove the BUG_ON and always return the
error to be handled appropriately by the caller.

Acked-by: Martijn Coenen <maco@android.com>
Reported-by: syzbot+3ae18325f96190606754@syzkaller.appspotmail.com
Fixes: bde4a19fc0 ("binder: use userspace pointer as base of buffer space")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-01 08:42:47 +02:00

176 lines
6.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2017 Google, Inc.
*/
#ifndef _LINUX_BINDER_ALLOC_H
#define _LINUX_BINDER_ALLOC_H
#include <linux/rbtree.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/rtmutex.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/list_lru.h>
#include <uapi/linux/android/binder.h>
extern struct list_lru binder_alloc_lru;
struct binder_transaction;
/**
* struct binder_buffer - buffer used for binder transactions
* @entry: entry alloc->buffers
* @rb_node: node for allocated_buffers/free_buffers rb trees
* @free: %true if buffer is free
* @allow_user_free: %true if user is allowed to free buffer
* @async_transaction: %true if buffer is in use for an async txn
* @debug_id: unique ID for debugging
* @transaction: pointer to associated struct binder_transaction
* @target_node: struct binder_node associated with this buffer
* @data_size: size of @transaction data
* @offsets_size: size of array of offsets
* @extra_buffers_size: size of space for other objects (like sg lists)
* @user_data: user pointer to base of buffer space
*
* Bookkeeping structure for binder transaction buffers
*/
struct binder_buffer {
struct list_head entry; /* free and allocated entries by address */
struct rb_node rb_node; /* free entry by size or allocated entry */
/* by address */
unsigned free:1;
unsigned allow_user_free:1;
unsigned async_transaction:1;
unsigned debug_id:29;
struct binder_transaction *transaction;
struct binder_node *target_node;
size_t data_size;
size_t offsets_size;
size_t extra_buffers_size;
void __user *user_data;
};
/**
* struct binder_lru_page - page object used for binder shrinker
* @page_ptr: pointer to physical page in mmap'd space
* @lru: entry in binder_alloc_lru
* @alloc: binder_alloc for a proc
*/
struct binder_lru_page {
struct list_head lru;
struct page *page_ptr;
struct binder_alloc *alloc;
};
/**
* struct binder_alloc - per-binder proc state for binder allocator
* @vma: vm_area_struct passed to mmap_handler
* (invarient after mmap)
* @tsk: tid for task that called init for this proc
* (invariant after init)
* @vma_vm_mm: copy of vma->vm_mm (invarient after mmap)
* @buffer: base of per-proc address space mapped via mmap
* @buffers: list of all buffers for this proc
* @free_buffers: rb tree of buffers available for allocation
* sorted by size
* @allocated_buffers: rb tree of allocated buffers sorted by address
* @free_async_space: VA space available for async buffers. This is
* initialized at mmap time to 1/2 the full VA space
* @pages: array of binder_lru_page
* @buffer_size: size of address space specified via mmap
* @pid: pid for associated binder_proc (invariant after init)
* @pages_high: high watermark of offset in @pages
*
* Bookkeeping structure for per-proc address space management for binder
* buffers. It is normally initialized during binder_init() and binder_mmap()
* calls. The address space is used for both user-visible buffers and for
* struct binder_buffer objects used to track the user buffers
*/
struct binder_alloc {
struct mutex mutex;
struct vm_area_struct *vma;
struct mm_struct *vma_vm_mm;
void __user *buffer;
struct list_head buffers;
struct rb_root free_buffers;
struct rb_root allocated_buffers;
size_t free_async_space;
struct binder_lru_page *pages;
size_t buffer_size;
uint32_t buffer_free;
int pid;
size_t pages_high;
};
#ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST
void binder_selftest_alloc(struct binder_alloc *alloc);
#else
static inline void binder_selftest_alloc(struct binder_alloc *alloc) {}
#endif
enum lru_status binder_alloc_free_page(struct list_head *item,
struct list_lru_one *lru,
spinlock_t *lock, void *cb_arg);
extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
size_t data_size,
size_t offsets_size,
size_t extra_buffers_size,
int is_async);
extern void binder_alloc_init(struct binder_alloc *alloc);
extern int binder_alloc_shrinker_init(void);
extern void binder_alloc_vma_close(struct binder_alloc *alloc);
extern struct binder_buffer *
binder_alloc_prepare_to_free(struct binder_alloc *alloc,
uintptr_t user_ptr);
extern void binder_alloc_free_buf(struct binder_alloc *alloc,
struct binder_buffer *buffer);
extern int binder_alloc_mmap_handler(struct binder_alloc *alloc,
struct vm_area_struct *vma);
extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
extern void binder_alloc_print_allocated(struct seq_file *m,
struct binder_alloc *alloc);
void binder_alloc_print_pages(struct seq_file *m,
struct binder_alloc *alloc);
/**
* binder_alloc_get_free_async_space() - get free space available for async
* @alloc: binder_alloc for this proc
*
* Return: the bytes remaining in the address-space for async transactions
*/
static inline size_t
binder_alloc_get_free_async_space(struct binder_alloc *alloc)
{
size_t free_async_space;
mutex_lock(&alloc->mutex);
free_async_space = alloc->free_async_space;
mutex_unlock(&alloc->mutex);
return free_async_space;
}
unsigned long
binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
struct binder_buffer *buffer,
binder_size_t buffer_offset,
const void __user *from,
size_t bytes);
int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
struct binder_buffer *buffer,
binder_size_t buffer_offset,
void *src,
size_t bytes);
int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
void *dest,
struct binder_buffer *buffer,
binder_size_t buffer_offset,
size_t bytes);
#endif /* _LINUX_BINDER_ALLOC_H */