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Commit c44b1231 authored by Todd Kjos's avatar Todd Kjos Committed by Greg Kroah-Hartman
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binder: add protection for non-perf cases 

Add binder_dead_nodes_lock, binder_procs_lock, and
binder_context_mgr_node_lock to protect the associated global lists
Signed-off-by: default avatarTodd Kjos <tkjos@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1cf29cf4
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Showing with 63 additions and 18 deletions
drivers/android/binder.c
View file @ c44b1231
......@@ -46,12 +46,16 @@
#include "binder_trace.h"
static DEFINE_MUTEX(binder_main_lock);
static HLIST_HEAD(binder_deferred_list);
static DEFINE_MUTEX(binder_deferred_lock);
static HLIST_HEAD(binder_devices);
static HLIST_HEAD(binder_procs);
static HLIST_HEAD(binder_deferred_list);
static DEFINE_MUTEX(binder_procs_lock);
static HLIST_HEAD(binder_dead_nodes);
static DEFINE_SPINLOCK(binder_dead_nodes_lock);
static struct dentry *binder_debugfs_dir_entry_root;
static struct dentry *binder_debugfs_dir_entry_proc;
......@@ -219,6 +223,8 @@ static struct binder_transaction_log_entry *binder_transaction_log_add(
struct binder_context {
struct binder_node *binder_context_mgr_node;
struct mutex context_mgr_node_lock;
kuid_t binder_context_mgr_uid;
const char *name;
};
......@@ -570,7 +576,9 @@ static int binder_dec_node(struct binder_node *node, int strong, int internal)
"refless node %d deleted\n",
node->debug_id);
} else {
spin_lock(&binder_dead_nodes_lock);
hlist_del(&node->dead_node);
spin_unlock(&binder_dead_nodes_lock);
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"dead node %d deleted\n",
node->debug_id);
......@@ -1454,11 +1462,14 @@ static void binder_transaction(struct binder_proc *proc,
}
target_node = ref->node;
} else {
mutex_lock(&context->context_mgr_node_lock);
target_node = context->binder_context_mgr_node;
if (target_node == NULL) {
return_error = BR_DEAD_REPLY;
mutex_unlock(&context->context_mgr_node_lock);
goto err_no_context_mgr_node;
}
mutex_unlock(&context->context_mgr_node_lock);
}
e->to_node = target_node->debug_id;
target_proc = target_node->proc;
......@@ -1824,22 +1835,31 @@ static int binder_thread_write(struct binder_proc *proc,
case BC_RELEASE:
case BC_DECREFS: {
uint32_t target;
struct binder_ref *ref;
struct binder_ref *ref = NULL;
const char *debug_string;
if (get_user(target, (uint32_t __user *)ptr))
return -EFAULT;
ptr += sizeof(uint32_t);
if (target == 0 && context->binder_context_mgr_node &&
if (target == 0 &&
(cmd == BC_INCREFS || cmd == BC_ACQUIRE)) {
ref = binder_get_ref_for_node(proc,
context->binder_context_mgr_node);
if (ref->desc != target) {
binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
proc->pid, thread->pid,
ref->desc);
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) {
ref = binder_get_ref_for_node(proc,
ctx_mgr_node);
if (ref && ref->desc != target) {
binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
proc->pid, thread->pid,
ref->desc);
}
}
} else
mutex_unlock(&context->context_mgr_node_lock);
}
if (ref == NULL)
ref = binder_get_ref(proc, target,
cmd == BC_ACQUIRE ||
cmd == BC_RELEASE);
......@@ -2753,9 +2773,10 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
int ret = 0;
struct binder_proc *proc = filp->private_data;
struct binder_context *context = proc->context;
struct binder_node *new_node;
kuid_t curr_euid = current_euid();
mutex_lock(&context->context_mgr_node_lock);
if (context->binder_context_mgr_node) {
pr_err("BINDER_SET_CONTEXT_MGR already set\n");
ret = -EBUSY;
......@@ -2776,16 +2797,18 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
} else {
context->binder_context_mgr_uid = curr_euid;
}
context->binder_context_mgr_node = binder_new_node(proc, 0, 0);
if (!context->binder_context_mgr_node) {
new_node = binder_new_node(proc, 0, 0);
if (!new_node) {
ret = -ENOMEM;
goto out;
}
context->binder_context_mgr_node->local_weak_refs++;
context->binder_context_mgr_node->local_strong_refs++;
context->binder_context_mgr_node->has_strong_ref = 1;
context->binder_context_mgr_node->has_weak_ref = 1;
new_node->local_weak_refs++;
new_node->local_strong_refs++;
new_node->has_strong_ref = 1;
new_node->has_weak_ref = 1;
context->binder_context_mgr_node = new_node;
out:
mutex_unlock(&context->context_mgr_node_lock);
return ret;
}
......@@ -2965,13 +2988,16 @@ static int binder_open(struct inode *nodp, struct file *filp)
binder_lock(__func__);
binder_stats_created(BINDER_STAT_PROC);
hlist_add_head(&proc->proc_node, &binder_procs);
proc->pid = current->group_leader->pid;
INIT_LIST_HEAD(&proc->delivered_death);
filp->private_data = proc;
binder_unlock(__func__);
mutex_lock(&binder_procs_lock);
hlist_add_head(&proc->proc_node, &binder_procs);
mutex_unlock(&binder_procs_lock);
if (binder_debugfs_dir_entry_proc) {
char strbuf[11];
......@@ -3050,7 +3076,10 @@ static int binder_node_release(struct binder_node *node, int refs)
node->proc = NULL;
node->local_strong_refs = 0;
node->local_weak_refs = 0;
spin_lock(&binder_dead_nodes_lock);
hlist_add_head(&node->dead_node, &binder_dead_nodes);
spin_unlock(&binder_dead_nodes_lock);
hlist_for_each_entry(ref, &node->refs, node_entry) {
refs++;
......@@ -3084,8 +3113,11 @@ static void binder_deferred_release(struct binder_proc *proc)
BUG_ON(proc->files);
mutex_lock(&binder_procs_lock);
hlist_del(&proc->proc_node);
mutex_unlock(&binder_procs_lock);
mutex_lock(&context->context_mgr_node_lock);
if (context->binder_context_mgr_node &&
context->binder_context_mgr_node->proc == proc) {
binder_debug(BINDER_DEBUG_DEAD_BINDER,
......@@ -3093,6 +3125,7 @@ static void binder_deferred_release(struct binder_proc *proc)
__func__, proc->pid);
context->binder_context_mgr_node = NULL;
}
mutex_unlock(&context->context_mgr_node_lock);
threads = 0;
active_transactions = 0;
......@@ -3509,13 +3542,17 @@ static int binder_state_show(struct seq_file *m, void *unused)
seq_puts(m, "binder state:\n");
spin_lock(&binder_dead_nodes_lock);
if (!hlist_empty(&binder_dead_nodes))
seq_puts(m, "dead nodes:\n");
hlist_for_each_entry(node, &binder_dead_nodes, dead_node)
print_binder_node(m, node);
spin_unlock(&binder_dead_nodes_lock);
mutex_lock(&binder_procs_lock);
hlist_for_each_entry(proc, &binder_procs, proc_node)
print_binder_proc(m, proc, 1);
mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
......@@ -3530,8 +3567,10 @@ static int binder_stats_show(struct seq_file *m, void *unused)
print_binder_stats(m, "", &binder_stats);
mutex_lock(&binder_procs_lock);
hlist_for_each_entry(proc, &binder_procs, proc_node)
print_binder_proc_stats(m, proc);
mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
......@@ -3543,8 +3582,10 @@ static int binder_transactions_show(struct seq_file *m, void *unused)
binder_lock(__func__);
seq_puts(m, "binder transactions:\n");
mutex_lock(&binder_procs_lock);
hlist_for_each_entry(proc, &binder_procs, proc_node)
print_binder_proc(m, proc, 0);
mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
......@@ -3556,12 +3597,15 @@ static int binder_proc_show(struct seq_file *m, void *unused)
binder_lock(__func__);
mutex_lock(&binder_procs_lock);
hlist_for_each_entry(itr, &binder_procs, proc_node) {
if (itr->pid == pid) {
seq_puts(m, "binder proc state:\n");
print_binder_proc(m, itr, 1);
}
}
mutex_unlock(&binder_procs_lock);
binder_unlock(__func__);
return 0;
}
......@@ -3622,6 +3666,7 @@ static int __init init_binder_device(const char *name)
binder_device->context.binder_context_mgr_uid = INVALID_UID;
binder_device->context.name = name;
mutex_init(&binder_device->context.context_mgr_node_lock);
ret = misc_register(&binder_device->miscdev);
if (ret < 0) {
......
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