public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Martijn Coenen <maco@android.com>
To: gregkh@linuxfoundation.org, john.stultz@linaro.org,
	tkjos@google.com, arve@android.com, amit.pundir@linaro.org
Cc: devel@driverdev.osuosl.org, maco@google.com,
	Martijn Coenen <maco@android.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2] ANDROID: binder: prevent transactions into own process.
Date: Wed, 28 Mar 2018 11:14:50 +0200	[thread overview]
Message-ID: <20180328091450.85073-1-maco@android.com> (raw)

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>
---
 drivers/android/binder.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 764b63a5aade..e578eee31589 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2839,6 +2839,14 @@ 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) {
+				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) {
 			/*
-- 
2.17.0.rc1.321.gba9d0f2565-goog

_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

             reply	other threads:[~2018-03-28  9:14 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-28  9:14 Martijn Coenen [this message]
2018-03-28 11:28 ` [PATCH v2] ANDROID: binder: prevent transactions into own process Greg KH
2018-03-28 11:34   ` Martijn Coenen
2018-04-23  8:07     ` Martijn Coenen
2018-04-23  8:24       ` Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180328091450.85073-1-maco@android.com \
    --to=maco@android.com \
    --cc=amit.pundir@linaro.org \
    --cc=arve@android.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=john.stultz@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maco@google.com \
    --cc=tkjos@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox