From e907b1314481c8586ff3793fd92c7dbd8aa841ae Mon Sep 17 00:00:00 2001 From: Hridya Valsaraju Date: Mon, 15 Jul 2019 12:18:04 -0700 Subject: binder: prevent transactions to context manager from its own process. commit 49ed96943a8e0c62cc5a9b0a6cfc88be87d1fcec 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 Acked-by: Todd Kjos Cc: stable Link: https://lore.kernel.org/r/20190715191804.112933-1-hridya@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 5d67f5fec6c1..1e0e438f079f 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2838,7 +2838,7 @@ 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; -- cgit v1.2.3