From nobody Mon Feb 9 05:58:36 2026 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD7001F1513 for ; Thu, 30 Jan 2025 21:58:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738274312; cv=none; b=klFE/WMwN+RigQ5j9KRXSU+N8M+zX00kCkLcCcF9vhCUNNsvwJpkNRRN+gMXPu3mi+VEwBMry3GfiexKCDroed3Y4x2BSEW3q5uSLXy5i1aMILpigSJWwbkeiOJapiaPi9MhKl3j+iTdvHJIaI4lSq633gzOxlcidin3x1aj4DM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738274312; c=relaxed/simple; bh=i84G3SmkD1FSn/qiCtc5Rh03DuaSUwH0up34eflh8ro=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=TM2eNrZEBSxWIs9V9FHIODhls1dJVBOTYPh09/oRdQM3Zn1E+Oc5nla2diyQeUlm8AWqroW3qrqV7sfhSkbbRAyAYreDCcl+ZCkJZaNDPTsHDV+NVn600+wql/uEUH2V5zFQmBlahbF0qXjQaXCqswvv+/kSsKVx5vo74WYgF/c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--cmllamas.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=SCDfb3fG; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--cmllamas.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="SCDfb3fG" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2ef79d9c692so3370259a91.0 for ; Thu, 30 Jan 2025 13:58:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738274310; x=1738879110; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=sP+PSXxGrOmF+G6y4EyqF6nMuKUGJmNHFz94ds/u0fQ=; b=SCDfb3fGuUvhHA0RUWsiQ/SWbiFIhRgaHK/cFuLMSBo8cSskAmpNx5VLqjmSt76hy8 TIOWx3UrKeUDIaYUX5VlMWPgfN+idLmWZdk9x2FzTkOE+6CJ1OzAZNqZJCUYEdYQGJke cdgjkxpZfoXqqsJR9OSffCDfOSxwZY9i/ZYdxjx5f4VekmmFbCbzj73sIMwSwEy1U+Am uAJ/9JW2CewtED6Y3j0DVOQsRaBiLMtFh8pPsF2dwrNsWY5pVTQvbT4KPxm1m84fRhJa 5bwXRA17ZrkYnSBEFG94SZJ7cwqftTgKFvcIuyYBdP2JlQIEPdPwc7SvOxhTsj/NM2eu gjsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738274310; x=1738879110; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=sP+PSXxGrOmF+G6y4EyqF6nMuKUGJmNHFz94ds/u0fQ=; b=oiwmY3nxwcq8r7RW522Ak8YtJ4z9nJg16tx//UZWRMxDdTX+EZabmsKNt06NAUM1RE v+kq685bNzz++QGDsENA3fVk+KmhgSieQI685PHnQgLEHidja7sYGMUbS/khpBXo7XEz eNNMldTkYgL6bW/vfIAuD45BQpL7P2lDQXXmOWNTfh0IcgY4ej10VByWjgJG2KQuNPnw qH3EUAboKZdwfdM4NIfwVrp9RxSDhHiCh9AKJN6IA1y/tT0XnSwrchGs3YbshjL2+Hzd nz6r0Ub2pJgn0ga4+cEHfniWQ6l214WHYT0GHoN5q9agyNfE+rytkOJ9LFHrCwzqOlFP aI7Q== X-Gm-Message-State: AOJu0YxO3BTToGDV1Wml75aBGijoq7nbs3DwZEpq/UpDlmwNDcEo00xI rFDqA3W6T7W3x3rLuaYAR4MvYnUXj33g4KVMfFg59WNyWpiOBZSh1X8V9YKtYeuwrZvWPG6zXXH xd+xwkwafxw== X-Google-Smtp-Source: AGHT+IGl1w1MKzWkKbM7ScftD/Z+sWuD+nXViJBNKnkiSS+kF4yMpnUpSO6IRT4QJWmuw8vNVTEla8I2jPf3nw== X-Received: from pfbbd35.prod.google.com ([2002:a05:6a00:27a3:b0:728:e508:8a3e]) (user=cmllamas job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:218a:b0:725:eb85:f7ef with SMTP id d2e1a72fcca58-72fd0bffcf0mr11984683b3a.14.1738274310017; Thu, 30 Jan 2025 13:58:30 -0800 (PST) Date: Thu, 30 Jan 2025 21:58:22 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.48.1.362.g079036d154-goog Message-ID: <20250130215823.1518990-1-cmllamas@google.com> Subject: [PATCH] binderfs: fix use-after-free in binder_devices From: Carlos Llamas To: Greg Kroah-Hartman , "=?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?=" , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Carlos Llamas , Suren Baghdasaryan , Li Li Cc: linux-kernel@vger.kernel.org, kernel-team@android.com, syzbot+7015dcf45953112c8b45@syzkaller.appspotmail.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Devices created through binderfs are added to the global binder_devices list but are not removed before being destroyed. This leads to dangling pointers in the list and subsequent use-after-free errors: =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D BUG: KASAN: slab-use-after-free in binder_add_device+0x5c/0x9c Write of size 8 at addr ffff0000c258d708 by task mount/653 CPU: 7 UID: 0 PID: 653 Comm: mount Not tainted 6.13.0-09030-g6d61a53dd6f5= #1 Hardware name: linux,dummy-virt (DT) Call trace: binder_add_device+0x5c/0x9c binderfs_binder_device_create+0x690/0x84c [...] __arm64_sys_mount+0x324/0x3bc Allocated by task 632: binderfs_binder_device_create+0x168/0x84c binder_ctl_ioctl+0xfc/0x184 [...] __arm64_sys_ioctl+0x110/0x150 Freed by task 649: kfree+0xe0/0x338 binderfs_evict_inode+0x138/0x1dc [...] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Remove devices from binder_devices before destroying them. Cc: Li Li Reported-by: syzbot+7015dcf45953112c8b45@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3D7015dcf45953112c8b45 Fixes: 12d909cac1e1 ("binderfs: add new binder devices to binder_devices") Signed-off-by: Carlos Llamas --- drivers/android/binderfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c index bc6bae76ccaf..94c6446604fc 100644 --- a/drivers/android/binderfs.c +++ b/drivers/android/binderfs.c @@ -274,6 +274,7 @@ static void binderfs_evict_inode(struct inode *inode) mutex_unlock(&binderfs_minors_mutex); =20 if (refcount_dec_and_test(&device->ref)) { + hlist_del_init(&device->hlist); kfree(device->context.name); kfree(device); } --=20 2.48.1.362.g079036d154-goog