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Diffstat (limited to 'kernel/drivers/android/binder.c')
-rw-r--r--kernel/drivers/android/binder.c35
1 files changed, 26 insertions, 9 deletions
diff --git a/kernel/drivers/android/binder.c b/kernel/drivers/android/binder.c
index 7d00b7a01..47ddfefe2 100644
--- a/kernel/drivers/android/binder.c
+++ b/kernel/drivers/android/binder.c
@@ -1003,7 +1003,7 @@ static int binder_dec_node(struct binder_node *node, int strong, int internal)
static struct binder_ref *binder_get_ref(struct binder_proc *proc,
- uint32_t desc)
+ u32 desc, bool need_strong_ref)
{
struct rb_node *n = proc->refs_by_desc.rb_node;
struct binder_ref *ref;
@@ -1011,12 +1011,16 @@ static struct binder_ref *binder_get_ref(struct binder_proc *proc,
while (n) {
ref = rb_entry(n, struct binder_ref, rb_node_desc);
- if (desc < ref->desc)
+ if (desc < ref->desc) {
n = n->rb_left;
- else if (desc > ref->desc)
+ } else if (desc > ref->desc) {
n = n->rb_right;
- else
+ } else if (need_strong_ref && !ref->strong) {
+ binder_user_error("tried to use weak ref as strong ref\n");
+ return NULL;
+ } else {
return ref;
+ }
}
return NULL;
}
@@ -1286,7 +1290,10 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
} break;
case BINDER_TYPE_HANDLE:
case BINDER_TYPE_WEAK_HANDLE: {
- struct binder_ref *ref = binder_get_ref(proc, fp->handle);
+ struct binder_ref *ref;
+
+ ref = binder_get_ref(proc, fp->handle,
+ fp->type == BINDER_TYPE_HANDLE);
if (ref == NULL) {
pr_err("transaction release %d bad handle %d\n",
@@ -1380,7 +1387,7 @@ static void binder_transaction(struct binder_proc *proc,
if (tr->target.handle) {
struct binder_ref *ref;
- ref = binder_get_ref(proc, tr->target.handle);
+ ref = binder_get_ref(proc, tr->target.handle, true);
if (ref == NULL) {
binder_user_error("%d:%d got transaction to invalid handle\n",
proc->pid, thread->pid);
@@ -1571,7 +1578,9 @@ static void binder_transaction(struct binder_proc *proc,
fp->type = BINDER_TYPE_HANDLE;
else
fp->type = BINDER_TYPE_WEAK_HANDLE;
+ fp->binder = 0;
fp->handle = ref->desc;
+ fp->cookie = 0;
binder_inc_ref(ref, fp->type == BINDER_TYPE_HANDLE,
&thread->todo);
@@ -1583,7 +1592,10 @@ static void binder_transaction(struct binder_proc *proc,
} break;
case BINDER_TYPE_HANDLE:
case BINDER_TYPE_WEAK_HANDLE: {
- struct binder_ref *ref = binder_get_ref(proc, fp->handle);
+ struct binder_ref *ref;
+
+ ref = binder_get_ref(proc, fp->handle,
+ fp->type == BINDER_TYPE_HANDLE);
if (ref == NULL) {
binder_user_error("%d:%d got transaction with invalid handle, %d\n",
@@ -1618,7 +1630,9 @@ static void binder_transaction(struct binder_proc *proc,
return_error = BR_FAILED_REPLY;
goto err_binder_get_ref_for_node_failed;
}
+ fp->binder = 0;
fp->handle = new_ref->desc;
+ fp->cookie = 0;
binder_inc_ref(new_ref, fp->type == BINDER_TYPE_HANDLE, NULL);
trace_binder_transaction_ref_to_ref(t, ref,
new_ref);
@@ -1672,6 +1686,7 @@ static void binder_transaction(struct binder_proc *proc,
binder_debug(BINDER_DEBUG_TRANSACTION,
" fd %d -> %d\n", fp->handle, target_fd);
/* TODO: fput? */
+ fp->binder = 0;
fp->handle = target_fd;
} break;
@@ -1794,7 +1809,9 @@ static int binder_thread_write(struct binder_proc *proc,
ref->desc);
}
} else
- ref = binder_get_ref(proc, target);
+ ref = binder_get_ref(proc, target,
+ cmd == BC_ACQUIRE ||
+ cmd == BC_RELEASE);
if (ref == NULL) {
binder_user_error("%d:%d refcount change on invalid ref %d\n",
proc->pid, thread->pid, target);
@@ -1990,7 +2007,7 @@ static int binder_thread_write(struct binder_proc *proc,
if (get_user(cookie, (binder_uintptr_t __user *)ptr))
return -EFAULT;
ptr += sizeof(binder_uintptr_t);
- ref = binder_get_ref(proc, target);
+ ref = binder_get_ref(proc, target, false);
if (ref == NULL) {
binder_user_error("%d:%d %s invalid ref %d\n",
proc->pid, thread->pid,