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Christian Brauner d2437b10ba UPSTREAM: binderfs: use refcount for binder control devices too
Binderfs binder-control devices are cleaned up via binderfs_evict_inode
too() which will use refcount_dec_and_test(). However, we missed to set
the refcount for binderfs binder-control devices and so we underflowed
when the binderfs instance got unmounted. Pretty obvious oversight and
should have been part of the more general UAF fix. The good news is that
having test cases (suprisingly) helps.

Technically, we could detect that we're about to cleanup the
binder-control dentry in binderfs_evict_inode() and then simply clean it
up. But that makes the assumption that the binder driver itself will
never make use of a binderfs binder-control device after the binderfs
instance it belongs to has been unmounted and the superblock for it been
destroyed. While it is unlikely to ever come to this let's be on the
safe side. Performance-wise this also really doesn't matter since the
binder-control device is only every really when creating the binderfs
filesystem or creating additional binder devices. Both operations are
pretty rare.

Fixes: f0fe2c0f05 ("binder: prevent UAF for binderfs devices II")
Link: https://lore.kernel.org/r/CA+G9fYusdfg7PMfC9Xce-xLT7NiyKSbgojpK35GOm=Pf9jXXrA@mail.gmail.com
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20200311105309.1742827-1-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 211b64e4b5)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Idb5e9e8945fa95506f3ff4f15bde3efaf65d7c9f
2020-11-16 07:43:08 +01:00
android ANDROID: GKI: update the ABI xml 2020-10-30 12:21:53 +08:00
arch UPSTREAM: um: Fix header inclusion 2020-11-16 07:43:08 +01:00
block This is the 4.19.156 stable release 2020-11-10 13:23:09 +01:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto This is the 4.19.153 stable release 2020-10-29 11:36:20 +01:00
Documentation This is the 4.19.155 stable release 2020-11-05 14:02:27 +01:00
drivers UPSTREAM: binderfs: use refcount for binder control devices too 2020-11-16 07:43:08 +01:00
firmware Fix built-in early-load Intel microcode alignment 2020-01-23 08:21:29 +01:00
fs UPSTREAM: fscrypt: restrict IV_INO_LBLK_* to AES-256-XTS 2020-11-15 15:06:09 +01:00
include UPSTREAM: ipv6: ndisc: RFC-ietf-6man-ra-pref64-09 is now published as RFC8781 2020-11-16 07:43:08 +01:00
init This is the 4.19.155 stable release 2020-11-05 14:02:27 +01:00
ipc Revert "ANDROID: vfs: Add permission2 for filesystems with per mount permissions" 2020-06-27 15:17:42 +02:00
kernel This is the 4.19.156 stable release 2020-11-10 13:23:09 +01:00
lib This is the 4.19.156 stable release 2020-11-10 13:23:09 +01:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm UPSTREAM: mm/filemap.c: don't bother dropping mmap_sem for zero size readahead 2020-11-16 07:43:08 +01:00
net This is the 4.19.156 stable release 2020-11-10 13:23:09 +01:00
samples This is the 4.19.154 stable release 2020-10-30 11:43:26 +01:00
scripts Revert "ANDROID: Kbuild, LLVMLinux: allow overriding clang target triple" 2020-11-10 11:47:24 -08:00
security This is the 4.19.155 stable release 2020-11-05 14:02:27 +01:00
sound This is the 4.19.156 stable release 2020-11-10 13:23:09 +01:00
tools This is the 4.19.156 stable release 2020-11-10 13:23:09 +01:00
usr initramfs: restore default compression behavior 2020-04-13 10:44:59 +02:00
virt KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch 2020-10-01 13:14:54 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
build.config.aarch64 Revert "ANDROID: Kbuild, LLVMLinux: allow overriding clang target triple" 2020-11-10 11:47:24 -08:00
build.config.allmodconfig Revert "ANDROID: Kbuild, LLVMLinux: allow overriding clang target triple" 2020-11-10 11:47:24 -08:00
build.config.allmodconfig.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.allmodconfig.arm ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.allmodconfig.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.arm Revert "ANDROID: Kbuild, LLVMLinux: allow overriding clang target triple" 2020-11-10 11:47:24 -08:00
build.config.common ANDROID: clang: update to 11.0.5 2020-10-27 11:18:23 -07:00
build.config.gki ANDROID: gki: Removed cf modules from gki_defconfig 2020-01-31 16:23:38 -08:00
build.config.gki_kasan ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.gki_kasan.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.gki_kasan.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.gki-debug.aarch64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.gki-debug.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.gki.aarch64 ANDROID: GKI: prevent removal of monitored symbols 2020-09-29 11:48:43 +01:00
build.config.gki.x86_64 ANDROID: drop KERNEL_DIR setting in build.config.common 2020-09-25 15:14:51 +08:00
build.config.x86_64 Revert "ANDROID: Kbuild, LLVMLinux: allow overriding clang target triple" 2020-11-10 11:47:24 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS UPSTREAM: net: WireGuard secure network tunnel 2020-10-25 11:48:12 +01:00
Makefile This is the 4.19.157 stable release 2020-11-11 11:16:11 +01:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.