binder: prevent transactions to context manager from its own process.

commit 49ed96943a upstream.

Currently, a transaction to context manager from its own process
is prevented by checking if its binder_proc struct is the same as
that of the sender. However, this would not catch cases where the
process opens the binder device again and uses the new fd to send
a transaction to the context manager.

Reported-by: syzbot+8b3c354d33c4ac78bfad@syzkaller.appspotmail.com
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190715191804.112933-1-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hridya Valsaraju
2019-07-15 12:18:04 -07:00
committed by Greg Kroah-Hartman
parent 6378b847d7
commit 74402b5c3f

View File

@@ -2785,7 +2785,7 @@ static void binder_transaction(struct binder_proc *proc,
else
return_error = BR_DEAD_REPLY;
mutex_unlock(&context->context_mgr_node_lock);
if (target_node && target_proc == proc) {
if (target_node && target_proc->pid == proc->pid) {
binder_user_error("%d:%d got transaction to context manager from process owning it\n",
proc->pid, thread->pid);
return_error = BR_FAILED_REPLY;