From: Kees Cook <keescook@chromium.org>
To: Christian Brauner <brauner@kernel.org>, Will Deacon <will@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
Al Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>,
Zack Rusin <zack.rusin@broadcom.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@broadcom.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
Jani Nikula <jani.nikula@linux.intel.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Tvrtko Ursulin <tursulin@ursulin.net>,
Andi Shyti <andi.shyti@linux.intel.com>,
Lucas De Marchi <lucas.demarchi@intel.com>,
Matt Atwood <matthew.s.atwood@intel.com>,
Matthew Auld <matthew.auld@intel.com>,
Nirmoy Das <nirmoy.das@intel.com>,
Jonathan Cavitt <jonathan.cavitt@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Boqun Feng <boqun.feng@gmail.com>,
Mark Rutland <mark.rutland@arm.com>,
Kent Overstreet <kent.overstreet@linux.dev>,
Masahiro Yamada <masahiroy@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nicolas Schier <nicolas@fjasle.eu>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org,
linux-kbuild@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH 0/5] fs: Do not allow get_file() to resurrect 0 f_count
Date: Thu, 2 May 2024 15:33:35 -0700 [thread overview]
Message-ID: <20240502222252.work.690-kees@kernel.org> (raw)
Hi,
Failure with f_count reference counting are better contained by
an actual reference counting type, like refcount_t. The first step
is for get_file() to use inc_not_zero to avoid resurrection. I also
found a couple open-coded modifications of f_count that should be using
get_file(). Since long ago, f_count was switched to atomic_long_t, so to
get proper reference count checking, I've added a refcount_long_t API,
and then converted f_count to refcount_long_t.
Now if there are underflows (or somehow an overflow), we'll see them
reported.
-Kees
Kees Cook (5):
fs: Do not allow get_file() to resurrect 0 f_count
drm/vmwgfx: Do not directly manipulate file->f_count
drm/i915: Do not directly manipulate file->f_count
refcount: Introduce refcount_long_t and APIs
fs: Convert struct file::f_count to refcount_long_t
MAINTAINERS | 2 +-
Makefile | 11 +-
drivers/gpu/drm/i915/gt/shmem_utils.c | 5 +-
drivers/gpu/drm/vmwgfx/ttm_object.c | 2 +-
fs/file.c | 4 +-
fs/file_table.c | 6 +-
include/linux/fs.h | 7 +-
include/linux/refcount-impl.h | 344 ++++++++++++++++++++++++++
include/linux/refcount.h | 341 +------------------------
include/linux/refcount_types.h | 12 +
lib/refcount.c | 17 +-
11 files changed, 398 insertions(+), 353 deletions(-)
create mode 100644 include/linux/refcount-impl.h
--
2.34.1
next reply other threads:[~2024-05-02 22:33 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-02 22:33 Kees Cook [this message]
2024-05-02 22:33 ` [PATCH 1/5] fs: Do not allow get_file() to resurrect 0 f_count Kees Cook
2024-05-02 22:53 ` Jann Horn
2024-05-02 23:03 ` Kees Cook
2024-05-03 9:02 ` Christian Brauner
2024-05-06 10:41 ` Hillf Danton
2024-05-02 22:33 ` [PATCH 2/5] drm/vmwgfx: Do not directly manipulate file->f_count Kees Cook
2024-05-02 22:33 ` [PATCH 3/5] drm/i915: " Kees Cook
2024-05-02 22:33 ` [PATCH 4/5] refcount: Introduce refcount_long_t and APIs Kees Cook
2024-05-06 8:04 ` kernel test robot
2024-05-02 22:33 ` [PATCH 5/5] fs: Convert struct file::f_count to refcount_long_t Kees Cook
2024-05-02 22:42 ` Al Viro
2024-05-02 22:52 ` Kees Cook
2024-05-02 23:12 ` Al Viro
2024-05-02 23:21 ` Kees Cook
2024-05-02 23:41 ` Al Viro
2024-05-03 0:10 ` Kees Cook
2024-05-03 0:14 ` Al Viro
2024-05-03 0:41 ` Kees Cook
2024-05-03 9:37 ` Christian Brauner
2024-05-03 10:36 ` Peter Zijlstra
2024-05-03 11:35 ` Christian Brauner
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