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path: root/drivers/android/binder.c
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Diffstat (limited to 'drivers/android/binder.c')
-rw-r--r--drivers/android/binder.c89
1 files changed, 45 insertions, 44 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 05e75d18b4d9..2412e219b7c3 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -286,7 +286,7 @@ struct binder_device {
struct binder_work {
struct list_head entry;
- enum {
+ enum binder_work_type {
BINDER_WORK_TRANSACTION = 1,
BINDER_WORK_TRANSACTION_COMPLETE,
BINDER_WORK_RETURN_ERROR,
@@ -484,6 +484,9 @@ enum binder_deferred_state {
* @files files_struct for process
* (protected by @files_lock)
* @files_lock mutex to protect @files
+ * @cred struct cred associated with the `struct file`
+ * in binder_open()
+ * (invariant after initialized)
* @deferred_work_node: element for binder_deferred_list
* (protected by binder_deferred_lock)
* @deferred_work: bitmap of deferred work to perform
@@ -532,6 +535,7 @@ struct binder_proc {
struct task_struct *tsk;
struct files_struct *files;
struct mutex files_lock;
+ const struct cred *cred;
struct hlist_node deferred_work_node;
int deferred_work;
bool is_dead;
@@ -850,27 +854,6 @@ static struct binder_work *binder_dequeue_work_head_ilocked(
return w;
}
-/**
- * binder_dequeue_work_head() - Dequeues the item at head of list
- * @proc: binder_proc associated with list
- * @list: list to dequeue head
- *
- * Removes the head of the list if there are items on the list
- *
- * Return: pointer dequeued binder_work, NULL if list was empty
- */
-static struct binder_work *binder_dequeue_work_head(
- struct binder_proc *proc,
- struct list_head *list)
-{
- struct binder_work *w;
-
- binder_inner_proc_lock(proc);
- w = binder_dequeue_work_head_ilocked(list);
- binder_inner_proc_unlock(proc);
- return w;
-}
-
static void
binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer);
static void binder_free_thread(struct binder_thread *thread);
@@ -2302,7 +2285,7 @@ static int binder_translate_binder(struct flat_binder_object *fp,
ret = -EINVAL;
goto done;
}
- if (security_binder_transfer_binder(proc->tsk, target_proc->tsk)) {
+ if (security_binder_transfer_binder(proc->cred, target_proc->cred)) {
ret = -EPERM;
goto done;
}
@@ -2348,7 +2331,7 @@ static int binder_translate_handle(struct flat_binder_object *fp,
proc->pid, thread->pid, fp->handle);
return -EINVAL;
}
- if (security_binder_transfer_binder(proc->tsk, target_proc->tsk)) {
+ if (security_binder_transfer_binder(proc->cred, target_proc->cred)) {
ret = -EPERM;
goto done;
}
@@ -2432,7 +2415,7 @@ static int binder_translate_fd(int fd,
ret = -EBADF;
goto err_fget;
}
- ret = security_binder_transfer_file(proc->tsk, target_proc->tsk, file);
+ ret = security_binder_transfer_file(proc->cred, target_proc->cred, file);
if (ret < 0) {
ret = -EPERM;
goto err_security;
@@ -2813,8 +2796,14 @@ static void binder_transaction(struct binder_proc *proc,
goto err_dead_binder;
}
e->to_node = target_node->debug_id;
- if (security_binder_transaction(proc->tsk,
- target_proc->tsk) < 0) {
+ if (WARN_ON(proc == target_proc)) {
+ return_error = BR_FAILED_REPLY;
+ return_error_param = -EINVAL;
+ return_error_line = __LINE__;
+ goto err_invalid_target_handle;
+ }
+ if (security_binder_transaction(proc->cred,
+ target_proc->cred) < 0) {
return_error = BR_FAILED_REPLY;
return_error_param = -EPERM;
return_error_line = __LINE__;
@@ -3288,10 +3277,17 @@ static int binder_thread_write(struct binder_proc *proc,
struct binder_node *ctx_mgr_node;
mutex_lock(&context->context_mgr_node_lock);
ctx_mgr_node = context->binder_context_mgr_node;
- if (ctx_mgr_node)
+ if (ctx_mgr_node) {
+ if (ctx_mgr_node->proc == proc) {
+ binder_user_error("%d:%d context manager tried to acquire desc 0\n",
+ proc->pid, thread->pid);
+ mutex_unlock(&context->context_mgr_node_lock);
+ return -EINVAL;
+ }
ret = binder_inc_ref_for_node(
proc, ctx_mgr_node,
strong, NULL, &rdata);
+ }
mutex_unlock(&context->context_mgr_node_lock);
}
if (ret)
@@ -4149,13 +4145,17 @@ static void binder_release_work(struct binder_proc *proc,
struct list_head *list)
{
struct binder_work *w;
+ enum binder_work_type wtype;
while (1) {
- w = binder_dequeue_work_head(proc, list);
+ binder_inner_proc_lock(proc);
+ w = binder_dequeue_work_head_ilocked(list);
+ wtype = w ? w->type : 0;
+ binder_inner_proc_unlock(proc);
if (!w)
return;
- switch (w->type) {
+ switch (wtype) {
case BINDER_WORK_TRANSACTION: {
struct binder_transaction *t;
@@ -4189,9 +4189,11 @@ static void binder_release_work(struct binder_proc *proc,
kfree(death);
binder_stats_deleted(BINDER_STAT_DEATH);
} break;
+ case BINDER_WORK_NODE:
+ break;
default:
pr_err("unexpected work type, %d, not freed\n",
- w->type);
+ wtype);
break;
}
}
@@ -4263,6 +4265,7 @@ static void binder_free_proc(struct binder_proc *proc)
BUG_ON(!list_empty(&proc->delivered_death));
binder_alloc_deferred_release(&proc->alloc);
put_task_struct(proc->tsk);
+ put_cred(proc->cred);
binder_stats_deleted(BINDER_STAT_PROC);
kfree(proc);
}
@@ -4333,23 +4336,20 @@ static int binder_thread_release(struct binder_proc *proc,
}
/*
- * If this thread used poll, make sure we remove the waitqueue
- * from any epoll data structures holding it with POLLFREE.
- * waitqueue_active() is safe to use here because we're holding
- * the inner lock.
+ * If this thread used poll, make sure we remove the waitqueue from any
+ * poll data structures holding it.
*/
- if ((thread->looper & BINDER_LOOPER_STATE_POLL) &&
- waitqueue_active(&thread->wait)) {
- wake_up_poll(&thread->wait, POLLHUP | POLLFREE);
- }
+ if (thread->looper & BINDER_LOOPER_STATE_POLL)
+ wake_up_pollfree(&thread->wait);
binder_inner_proc_unlock(thread->proc);
/*
- * This is needed to avoid races between wake_up_poll() above and
- * and ep_remove_waitqueue() called for other reasons (eg the epoll file
- * descriptor being closed); ep_remove_waitqueue() holds an RCU read
- * lock, so we can be sure it's done after calling synchronize_rcu().
+ * This is needed to avoid races between wake_up_pollfree() above and
+ * someone else removing the last entry from the queue for other reasons
+ * (e.g. ep_remove_wait_queue() being called due to an epoll file
+ * descriptor being closed). Such other users hold an RCU read lock, so
+ * we can be sure they're done after we call synchronize_rcu().
*/
if (thread->looper & BINDER_LOOPER_STATE_POLL)
synchronize_rcu();
@@ -4466,7 +4466,7 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
ret = -EBUSY;
goto out;
}
- ret = security_binder_set_context_mgr(proc->tsk);
+ ret = security_binder_set_context_mgr(proc->cred);
if (ret < 0)
goto out;
if (uid_valid(context->binder_context_mgr_uid)) {
@@ -4719,6 +4719,7 @@ static int binder_open(struct inode *nodp, struct file *filp)
get_task_struct(current->group_leader);
proc->tsk = current->group_leader;
mutex_init(&proc->files_lock);
+ proc->cred = get_cred(filp->f_cred);
INIT_LIST_HEAD(&proc->todo);
proc->default_priority = task_nice(current);
binder_dev = container_of(filp->private_data, struct binder_device,
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-30 13:51:14 +0000