4.16-stable review patch. If anyone has any objections, please let me know.
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From: Martijn Coenen maco@android.com
commit 7aa135fcf26377f92dc0680a57566b4c7f3e281b upstream.
This can't happen with normal nodes (because you can't get a ref to a node you own), but it could happen with the context manager; to make the behavior consistent with regular nodes, reject transactions into the context manager by the process owning it.
Reported-by: syzbot+09e05aba06723a94d43d@syzkaller.appspotmail.com Signed-off-by: Martijn Coenen maco@android.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/android/binder.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2839,6 +2839,14 @@ static void binder_transaction(struct bi else return_error = BR_DEAD_REPLY; mutex_unlock(&context->context_mgr_node_lock); + if (target_node && target_proc == proc) { + binder_user_error("%d:%d got transaction to context manager from process owning it\n", + proc->pid, thread->pid); + return_error = BR_FAILED_REPLY; + return_error_param = -EINVAL; + return_error_line = __LINE__; + goto err_invalid_target_handle; + } } if (!target_node) { /*