4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martijn Coenen <maco@xxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Martijn Coenen <maco@xxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/android/binder.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2785,6 +2785,14 @@ 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) { /*