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"Reset" is the only command that needs to wait for interrupt from
the device before continuing, so let's factor our waiting logic from
__i2c_hid_command() to make it simpler.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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The main object in the driver is struct i2c_hid so it makes more sense
to pass it around instead of passing i2c_client and then fetching
i2c_hid associated with it.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Internally kernel prepends all report buffers, for both numbered and
unnumbered reports, with report ID, therefore to properly handle unnumbered
reports we should prepend it ourselves.
For the same reason we should skip the first byte of the buffer when
calling i2c_hid_set_or_send_report() which then will take care of properly
formatting the transfer buffer based on its separate report ID argument
along with report payload.
[jkosina@suse.cz: finalize trimmed sentence in changelog as spotted by Benjamin]
Fixes: 9b5a9ae88573 ("HID: i2c-hid: implement ll_driver transport-layer callbacks")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Special handling of numbered reports with IDs of 15 and above is only
needed when executing what HID-I2C spec is calling "Class Specific
Requests", and not when simply sending output reports.
Additionally, our mangling of report ID in i2c_hid_set_or_send_report()
resulted in incorrect report ID being written into SET_REPORT command
payload.
To solve it let's move all the report ID manipulation into
__i2c_hid_command() where we form the command data structure.
Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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gvt-fixes-2022-01-13
- Make DRM_I915_GVT depend on X86 (Siva Mullati)
- Clean kernel doc in gtt.c (Randy Dunlap)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
From: Zhi Wang <zhi.wang.linux@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1f619581-e3da-3899-09ac-f714d954a580@gmail.com
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We already have the gem/i915_gem_domain.c file.
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/8208321ad09f1fb0d1a61dc0f2449cce8b23a9b9.1644507885.git.jani.nikula@intel.com
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The problem I'm addressing was discovered by the LTP test covering
cve-2018-1000204.
A short description of what happens follows:
1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO
interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV
and a corresponding dxferp. The peculiar thing about this is that TUR
is not reading from the device.
2) In sg_start_req() the invocation of blk_rq_map_user() effectively
bounces the user-space buffer. As if the device was to transfer into
it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in
sg_build_indirect()") we make sure this first bounce buffer is
allocated with GFP_ZERO.
3) For the rest of the story we keep ignoring that we have a TUR, so the
device won't touch the buffer we prepare as if the we had a
DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device
and the buffer allocated by SG is mapped by the function
virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here
scatter-gather and not scsi generics). This mapping involves bouncing
via the swiotlb (we need swiotlb to do virtio in protected guest like
s390 Secure Execution, or AMD SEV).
4) When the SCSI TUR is done, we first copy back the content of the second
(that is swiotlb) bounce buffer (which most likely contains some
previous IO data), to the first bounce buffer, which contains all
zeros. Then we copy back the content of the first bounce buffer to
the user-space buffer.
5) The test case detects that the buffer, which it zero-initialized,
ain't all zeros and fails.
One can argue that this is an swiotlb problem, because without swiotlb
we leak all zeros, and the swiotlb should be transparent in a sense that
it does not affect the outcome (if all other participants are well
behaved).
Copying the content of the original buffer into the swiotlb buffer is
the only way I can think of to make swiotlb transparent in such
scenarios. So let's do just that if in doubt, but allow the driver
to tell us that the whole mapped buffer is going to be overwritten,
in which case we can preserve the old behavior and avoid the performance
impact of the extra bounce.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Legion Y9000X 2019 has the same speaker with Y9000X 2020,
but with a different quirk address. Add one quirk entry
to make the speaker work on Y9000X 2019 too.
Signed-off-by: Yu Huang <diwang90@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220212160835.165065-1-diwang90@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Commit 83b7dcbc51c930fc2079ab6c6fc9d719768321f1 introduced a generic
implicit feedback parser, which fails to execute for M-Audio FastTrack
Ultra sound cards. The issue is with the ENDPOINT_SYNCTYPE check in
add_generic_implicit_fb() where the SYNCTYPE is ADAPTIVE instead of ASYNC.
The reason is that the sync type of the FastTrack output endpoints are
set to adaptive in the quirks table since commit
65f04443c96dbda11b8fff21d6390e082846aa3c.
Fixes: 83b7dcbc51c9 ("ALSA: usb-audio: Add generic implicit fb parsing")
Signed-off-by: Matteo Martelli <matteomartelli3@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220211224913.20683-2-matteomartelli3@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Set the VM_DONTDUMP flag on mmap'ed VMAs to omit them from core
dumps. It's display-buffer memory; who knows what secrets these
buffers contain.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209155634.3994-3-tzimmermann@suse.de
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Initialize default vm_ops in static initialization of the GEM SHMEM funcs,
instead of the mmap code. It's simply better style. GEM helpers will later
set a VMA's vm_ops from the default automatically.
v2:
* also update the drivers that build upon GEM SHMEM
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209155634.3994-2-tzimmermann@suse.de
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We need the tty/serial fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the USB fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the staging driver fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the char/misc fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Simplify the control flow of mount_setattr_{prepare,commit} so they
become easier to follow. We kept using both an integer error variable
that was passed by pointer as well as a pointer as an indicator for
whether or not we need to revert or commit the prepared changes.
Simplify this and just use the pointer. If we successfully changed
properties the revert pointer will be NULL and if we failed to change
properties it will indicate where we failed and thus need to stop
reverting.
Link: https://lore.kernel.org/r/20220203131411.3093040-8-brauner@kernel.org
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Remove sb_prepare_remount_readonly()'s open-coded mnt_hold_writers()
implementation with the real helper we introduced in commit fbdc2f6c40f6
("fs: split out functions to hold writers").
Link: https://lore.kernel.org/r/20220203131411.3093040-7-brauner@kernel.org
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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In order to determine whether we need to call mnt_unhold_writers() in
mount_setattr_commit() we currently do not just check whether
MNT_WRITE_HOLD is set but also if a read-only mount was requested.
However, checking whether MNT_WRITE_HOLD is set is enough. Setting
MNT_WRITE_HOLD requires lock_mount_hash() to be held and it must be
unset before calling unlock_mount_hash(). This guarantees that if we see
MNT_WRITE_HOLD we know that we were the ones who set it earlier. We
don't need to care about why we set it. Plus, leaving this additional
read-only check in makes the code more confusing because it implies that
MNT_WRITE_HOLD could've been set by another thread when it really can't.
Remove it and update the associated comment.
Link: https://lore.kernel.org/r/20220203131411.3093040-6-brauner@kernel.org
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a tiny helper that lets us simplify the control-flow and can be used
in the next patch to avoid adding another condition open-coded into
mount_setattr_prepare(). Instead we can add it into the new helper.
Link: https://lore.kernel.org/r/20220203131411.3093040-5-brauner@kernel.org
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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When I introduced mnt_{hold,unhold}_writers() in commit fbdc2f6c40f6
("fs: split out functions to hold writers") I did not add kernel doc for
them. Fix this and introduce proper documentation.
Link: https://lore.kernel.org/r/20220203131411.3093040-4-brauner@kernel.org
Fixes: fbdc2f6c40f6 ("fs: split out functions to hold writers")
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Wraparound checks in there are redundant (x + y < x and
x + y < y are equivalent when x and y are both unsigned int).
IMO more straightforward code would be better here...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Warnings in assembly must use EMIT_WARN_ENTRY in order to generate
the necessary entry in exception table.
Check in EMIT_BUG_ENTRY that flags don't include BUGFLAG_WARNING.
This change avoids problems like the one fixed by
commit fd1eaaaaa686 ("powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug
warnings").
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ddcb422102a37eb45f57694c7ef0ec6187964dff.1644742951.git.christophe.leroy@csgroup.eu
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Allow additional arguments be passed to userprogs compilation.
Reproducible clang builds need to provide a sysroot and gcc path to
ensure the same toolchain is used across hosts. KCFLAGS is not currently
used for any user programs compilation, so add new USERCFLAGS and
USERLDFLAGS which serves similar purpose as HOSTCFLAGS/HOSTLDFLAGS.
Clang might detect GCC installation on hosts which have it installed
to a default location in /. With addition of these environment
variables, you can specify flags such as:
$ make USERCFLAGS=--sysroot=/path/to/sysroot
This can also be used to specify different sysroots such as musl or
bionic which may be installed on the host in paths that the compiler
may not search by default.
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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cmd_copy and cmd_shipped have similar functionality. The difference is
that cmd_copy uses 'cp' while cmd_shipped 'cat'.
Unify them into cmd_copy because this macro name is more intuitive.
Going forward, cmd_copy will use 'cat' to avoid the permission issue.
I also thought of 'cp --no-preserve=mode' but this option is not
mentioned in the POSIX spec [1], so I am keeping the 'cat' command.
[1]: https://pubs.opengroup.org/onlinepubs/009695299/utilities/cp.html
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
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Daniel asked for this for some intel deps, so let's do it now.
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Enable FORTIFY_SOURCE support for Clang:
Use the new __pass_object_size and __overloadable attributes so that
Clang will have appropriate visibility into argument sizes such that
__builtin_object_size(p, 1) will behave correctly. Additional details
available here:
https://github.com/llvm/llvm-project/issues/53516
https://github.com/ClangBuiltLinux/linux/issues/1401
A bug with __builtin_constant_p() of globally defined variables was
fixed in Clang 13 (and backported to 12.0.1), so FORTIFY support must
depend on that version or later. Additional details here:
https://bugs.llvm.org/show_bug.cgi?id=41459
commit a52f8a59aef4 ("fortify: Explicitly disable Clang support")
A bug with Clang's -mregparm=3 and -m32 makes some builtins unusable,
so removing -ffreestanding (to gain the needed libcall optimizations
with Clang) cannot be done. Without the libcall optimizations, Clang
cannot provide appropriate FORTIFY coverage, so it must be disabled
for CONFIG_X86_32. Additional details here;
https://github.com/llvm/llvm-project/issues/53645
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: George Burgess IV <gbiv@google.com>
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-9-keescook@chromium.org
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In preparation for enabling Clang FORTIFY_SOURCE support, redefine
strlen() as a macro that tests for being a constant expression
so that strlen() can still be used in static initializers, which is
lost when adding __pass_object_size and __overloadable.
An example of this usage can be seen here:
https://lore.kernel.org/all/202201252321.dRmWZ8wW-lkp@intel.com/
Notably, this constant expression feature of strlen() is not available
for architectures that build with -ffreestanding. This means the kernel
currently does not universally expect strlen() to be used this way, but
since there _are_ some build configurations that depend on it, retain
the characteristic for Clang FORTIFY_SOURCE builds too.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-8-keescook@chromium.org
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In preparation for using Clang's __pass_object_size, add __diagnose_as()
attributes to mark the functions as being the same as the indicated
builtins. When __daignose_as() is available, Clang will have a more
complete ability to apply its own diagnostic analysis to callers of these
functions, as if they were the builtins themselves. Without __diagnose_as,
Clang's compile time diagnostic messages won't be as precise as they
could be, but at least users of older toolchains will still benefit from
having fortified routines.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-7-keescook@chromium.org
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In preparation for using Clang's __pass_object_size attribute, make all
the pointer arguments to the fortified string functions const. Nothing
was changing their values anyway, so this added requirement (needed by
__pass_object_size) requires no code changes and has no impact on
the binary instruction output.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-6-keescook@chromium.org
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Clang will perform various compile-time diagnostics on uses of various
functions (e.g. simple bounds-checking on strcpy(), etc). These
diagnostics can be assigned to other functions (for example, new
implementations of the string functions under CONFIG_FORTIFY_SOURCE)
using the "diagnose_as_builtin" attribute. This allows those functions
to retain their compile-time diagnostic warnings.
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: llvm@lists.linux.dev
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220208225350.1331628-5-keescook@chromium.org
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In order for FORTIFY_SOURCE to use __pass_object_size on an "extern
inline" function, as all the fortified string functions are, the functions
must be marked as being overloadable (i.e. different prototypes due
to the implicitly injected object size arguments). This allows the
__pass_object_size versions to take precedence.
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: llvm@lists.linux.dev
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220208225350.1331628-4-keescook@chromium.org
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In order to gain greater visibility to type information when using
__builtin_object_size(), Clang has a function attribute "pass_object_size"
that will make size information available for marked arguments in
a function by way of implicit additional function arguments that are
then wired up the __builtin_object_size().
This is needed to implement FORTIFY_SOURCE in Clang, as a workaround
to Clang's __builtin_object_size() having limited visibility[1] into types
across function calls (even inlines).
This attribute has an additional benefit that it can be used even on
non-inline functions to gain argument size information.
[1] https://github.com/llvm/llvm-project/issues/53516
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: llvm@lists.linux.dev
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-3-keescook@chromium.org
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Replace open-coded gnu_inline attribute with the normal kernel
convention for attributes: __gnu_inline
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-2-keescook@chromium.org
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Clang 14 introduces support for compiletime_assert(). Update the
compile-time warning regex to catch Clang's variant of the warning text
in preparation for Clang supporting CONFIG_FORTIFY_SOURCE.
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/lkml/YfbtQKtpyAM1hHiC@dev-arch.archlinux-ax161
Signed-off-by: Kees Cook <keescook@chromium.org>
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As done for memcpy(), also update memset() to use the same tightened
compile-time bounds checking under CONFIG_FORTIFY_SOURCE.
Signed-off-by: Kees Cook <keescook@chromium.org>
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As done for memcpy(), also update memmove() to use the same tightened
compile-time checks under CONFIG_FORTIFY_SOURCE.
Signed-off-by: Kees Cook <keescook@chromium.org>
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memcpy() is dead; long live memcpy()
tl;dr: In order to eliminate a large class of common buffer overflow
flaws that continue to persist in the kernel, have memcpy() (under
CONFIG_FORTIFY_SOURCE) perform bounds checking of the destination struct
member when they have a known size. This would have caught all of the
memcpy()-related buffer write overflow flaws identified in at least the
last three years.
Background and analysis:
While stack-based buffer overflow flaws are largely mitigated by stack
canaries (and similar) features, heap-based buffer overflow flaws continue
to regularly appear in the kernel. Many classes of heap buffer overflows
are mitigated by FORTIFY_SOURCE when using the strcpy() family of
functions, but a significant number remain exposed through the memcpy()
family of functions.
At its core, FORTIFY_SOURCE uses the compiler's __builtin_object_size()
internal[0] to determine the available size at a target address based on
the compile-time known structure layout details. It operates in two
modes: outer bounds (0) and inner bounds (1). In mode 0, the size of the
enclosing structure is used. In mode 1, the size of the specific field
is used. For example:
struct object {
u16 scalar1; /* 2 bytes */
char array[6]; /* 6 bytes */
u64 scalar2; /* 8 bytes */
u32 scalar3; /* 4 bytes */
u32 scalar4; /* 4 bytes */
} instance;
__builtin_object_size(instance.array, 0) == 22, since the remaining size
of the enclosing structure starting from "array" is 22 bytes (6 + 8 +
4 + 4).
__builtin_object_size(instance.array, 1) == 6, since the remaining size
of the specific field "array" is 6 bytes.
The initial implementation of FORTIFY_SOURCE used mode 0 because there
were many cases of both strcpy() and memcpy() functions being used to
write (or read) across multiple fields in a structure. For example,
it would catch this, which is writing 2 bytes beyond the end of
"instance":
memcpy(&instance.array, data, 25);
While this didn't protect against overwriting adjacent fields in a given
structure, it would at least stop overflows from reaching beyond the
end of the structure into neighboring memory, and provided a meaningful
mitigation of a subset of buffer overflow flaws. However, many desirable
targets remain within the enclosing structure (for example function
pointers).
As it happened, there were very few cases of strcpy() family functions
intentionally writing beyond the end of a string buffer. Once all known
cases were removed from the kernel, the strcpy() family was tightened[1]
to use mode 1, providing greater mitigation coverage.
What remains is switching memcpy() to mode 1 as well, but making the
switch is much more difficult because of how frustrating it can be to
find existing "normal" uses of memcpy() that expect to write (or read)
across multiple fields. The root cause of the problem is that the C
language lacks a common pattern to indicate the intent of an author's
use of memcpy(), and is further complicated by the available compile-time
and run-time mitigation behaviors.
The FORTIFY_SOURCE mitigation comes in two halves: the compile-time half,
when both the buffer size _and_ the length of the copy is known, and the
run-time half, when only the buffer size is known. If neither size is
known, there is no bounds checking possible. At compile-time when the
compiler sees that a length will always exceed a known buffer size,
a warning can be deterministically emitted. For the run-time half,
the length is tested against the known size of the buffer, and the
overflowing operation is detected. (The performance overhead for these
tests is virtually zero.)
It is relatively easy to find compile-time false-positives since a warning
is always generated. Fixing the false positives, however, can be very
time-consuming as there are hundreds of instances. While it's possible
some over-read conditions could lead to kernel memory exposures, the bulk
of the risk comes from the run-time flaws where the length of a write
may end up being attacker-controlled and lead to an overflow.
Many of the compile-time false-positives take a form similar to this:
memcpy(&instance.scalar2, data, sizeof(instance.scalar2) +
sizeof(instance.scalar3));
and the run-time ones are similar, but lack a constant expression for the
size of the copy:
memcpy(instance.array, data, length);
The former is meant to cover multiple fields (though its style has been
frowned upon more recently), but has been technically legal. Both lack
any expressivity in the C language about the author's _intent_ in a way
that a compiler can check when the length isn't known at compile time.
A comment doesn't work well because what's needed is something a compiler
can directly reason about. Is a given memcpy() call expected to overflow
into neighbors? Is it not? By using the new struct_group() macro, this
intent can be much more easily encoded.
It is not as easy to find the run-time false-positives since the code path
to exercise a seemingly out-of-bounds condition that is actually expected
may not be trivially reachable. Tightening the restrictions to block an
operation for a false positive will either potentially create a greater
flaw (if a copy is truncated by the mitigation), or destabilize the kernel
(e.g. with a BUG()), making things completely useless for the end user.
As a result, tightening the memcpy() restriction (when there is a
reasonable level of uncertainty of the number of false positives), needs
to first WARN() with no truncation. (Though any sufficiently paranoid
end-user can always opt to set the panic_on_warn=1 sysctl.) Once enough
development time has passed, the mitigation can be further intensified.
(Note that this patch is only the compile-time checking step, which is
a prerequisite to doing run-time checking, which will come in future
patches.)
Given the potential frustrations of weeding out all the false positives
when tightening the run-time checks, it is reasonable to wonder if these
changes would actually add meaningful protection. Looking at just the
last three years, there are 23 identified flaws with a CVE that mention
"buffer overflow", and 11 are memcpy()-related buffer overflows.
(For the remaining 12: 7 are array index overflows that would be
mitigated by systems built with CONFIG_UBSAN_BOUNDS=y: CVE-2019-0145,
CVE-2019-14835, CVE-2019-14896, CVE-2019-14897, CVE-2019-14901,
CVE-2019-17666, CVE-2021-28952. 2 are miscalculated allocation
sizes which could be mitigated with memory tagging: CVE-2019-16746,
CVE-2019-2181. 1 is an iovec buffer bug maybe mitigated by memory tagging:
CVE-2020-10742. 1 is a type confusion bug mitigated by stack canaries:
CVE-2020-10942. 1 is a string handling logic bug with no mitigation I'm
aware of: CVE-2021-28972.)
At my last count on an x86_64 allmodconfig build, there are 35,294
calls to memcpy(). With callers instrumented to report all places
where the buffer size is known but the length remains unknown (i.e. a
run-time bounds check is added), we can count how many new run-time
bounds checks are added when the destination and source arguments of
memcpy() are changed to use "mode 1" bounds checking: 1,276. This means
for the future run-time checking, there is a worst-case upper bounds
of 3.6% false positives to fix. In addition, there were around 150 new
compile-time warnings to evaluate and fix (which have now been fixed).
With this instrumentation it's also possible to compare the places where
the known 11 memcpy() flaw overflows manifested against the resulting
list of potential new run-time bounds checks, as a measure of potential
efficacy of the tightened mitigation. Much to my surprise, horror, and
delight, all 11 flaws would have been detected by the newly added run-time
bounds checks, making this a distinctly clear mitigation improvement: 100%
coverage for known memcpy() flaws, with a possible 2 orders of magnitude
gain in coverage over existing but undiscovered run-time dynamic length
flaws (i.e. 1265 newly covered sites in addition to the 11 known), against
only <4% of all memcpy() callers maybe gaining a false positive run-time
check, with only about 150 new compile-time instances needing evaluation.
Specifically these would have been mitigated:
CVE-2020-24490 https://git.kernel.org/linus/a2ec905d1e160a33b2e210e45ad30445ef26ce0e
CVE-2020-12654 https://git.kernel.org/linus/3a9b153c5591548612c3955c9600a98150c81875
CVE-2020-12653 https://git.kernel.org/linus/b70261a288ea4d2f4ac7cd04be08a9f0f2de4f4d
CVE-2019-14895 https://git.kernel.org/linus/3d94a4a8373bf5f45cf5f939e88b8354dbf2311b
CVE-2019-14816 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-14815 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-14814 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-10126 https://git.kernel.org/linus/69ae4f6aac1578575126319d3f55550e7e440449
CVE-2019-9500 https://git.kernel.org/linus/1b5e2423164b3670e8bc9174e4762d297990deff
no-CVE-yet https://git.kernel.org/linus/130f634da1af649205f4a3dd86cbe5c126b57914
no-CVE-yet https://git.kernel.org/linus/d10a87a3535cce2b890897914f5d0d83df669c63
To accelerate the review of potential run-time false positives, it's
also worth noting that it is possible to partially automate checking
by examining the memcpy() buffer argument to check for the destination
struct member having a neighboring array member. It is reasonable to
expect that the vast majority of run-time false positives would look like
the already evaluated and fixed compile-time false positives, where the
most common pattern is neighboring arrays. (And, FWIW, many of the
compile-time fixes were actual bugs, so it is reasonable to assume we'll
have similar cases of actual bugs getting fixed for run-time checks.)
Implementation:
Tighten the memcpy() destination buffer size checking to use the actual
("mode 1") target buffer size as the bounds check instead of their
enclosing structure's ("mode 0") size. Use a common inline for memcpy()
(and memmove() in a following patch), since all the tests are the
same. All new cross-field memcpy() uses must use the struct_group() macro
or similar to target a specific range of fields, so that FORTIFY_SOURCE
can reason about the size and safety of the copy.
For now, cross-member "mode 1" _read_ detection at compile-time will be
limited to W=1 builds, since it is, unfortunately, very common. As the
priority is solving write overflows, read overflows will be part of a
future phase (and can be fixed in parallel, for anyone wanting to look
at W=1 build output).
For run-time, the "mode 0" size checking and mitigation is left unchanged,
with "mode 1" to be added in stages. In this patch, no new run-time
checks are added. Future patches will first bounds-check writes,
and only perform a WARN() for now. This way any missed run-time false
positives can be flushed out over the coming several development cycles,
but system builders who have tested their workloads to be WARN()-free
can enable the panic_on_warn=1 sysctl to immediately gain a mitigation
against this class of buffer overflows. Once that is under way, run-time
bounds-checking of reads can be similarly enabled.
Related classes of flaws that will remain unmitigated:
- memcpy() with flexible array structures, as the compiler does not
currently have visibility into the size of the trailing flexible
array. These can be fixed in the future by refactoring such cases
to use a new set of flexible array structure helpers to perform the
common serialization/deserialization code patterns doing allocation
and/or copying.
- memcpy() with raw pointers (e.g. void *, char *, etc), or otherwise
having their buffer size unknown at compile time, have no good
mitigation beyond memory tagging (and even that would only protect
against inter-object overflow, not intra-object neighboring field
overflows), or refactoring. Some kind of "fat pointer" solution is
likely needed to gain proper size-of-buffer awareness. (e.g. see
struct membuf)
- type confusion where a higher level type's allocation size does
not match the resulting cast type eventually passed to a deeper
memcpy() call where the compiler cannot see the true type. In
theory, greater static analysis could catch these, and the use
of -Warray-bounds will help find some of these.
[0] https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
[1] https://git.kernel.org/linus/6a39e62abbafd1d58d1722f40c7d26ef379c6a2f
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
With all known internal zero-length accesses fixed, it is possible to
enable -Wzero-length-bounds globally. Since this is included by default
in -Warray-bounds, we just need to stop disabling it.
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOd=bcs5W6eEDXGn5ROR2EuMiSp_2e6sLFxak=KK6yLWcvA@mail.gmail.com
|
|
With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE
coverage, it is now possible to enable -Warray-bounds. Since both GCC
and Clang include -Warray-bounds in -Wall, adjust the Makefile to just
stop disabling it.
Note that this option can be conservative in its warnings (which is
done at casting time rather than access time), but this is reasonable
since the cast variables may be accessed out of a scope where the true
size of the original object can't be evaluated. These handful of false
positives (which are arguably bad casts and can be easily avoided),
are worth dealing with because of the many places where this option
has helped identify missed bounds checks and even accesses done against
cases where a NULL pointer could be reached.
https://github.com/KSPP/linux/issues/109
https://github.com/KSPP/linux/issues/151
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org
Co-developed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
GCC 11 (incorrectly[1]) assumes that literal values cast to (void *)
should be treated like a NULL pointer with an offset, and raises
diagnostics when doing bounds checking:
In function '__memset',
inlined from '__bad_pagetable' at arch/alpha/mm/init.c:79:2:
./arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds]
37 | return __builtin_memset(s, c, n);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
In function '__memset',
inlined from '__bad_page' at arch/alpha/mm/init.c:86:2:
./arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds]
37 | return __builtin_memset(s, c, n);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
In function '__memset',
inlined from 'paging_init' at arch/alpha/mm/init.c:256:2:
./arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds]
37 | return __builtin_memset(s, c, n);
This has been solved in other places[2] already by using the recently
added absolute_pointer() macro. Do the same here.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578
[2] https://lore.kernel.org/all/20210912160149.2227137-1-linux@roeck-us.net/
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-alpha@vger.kernel.org
Reviewed-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
Similar to the recent arm64 fix[1], avoid overly wide casts in the m68k
cmpxchg implementation. Avoids this warning under -Warray-bounds with
GCC 11:
net/sched/cls_tcindex.c: In function 'tcindex_set_parms':
./arch/m68k/include/asm/cmpxchg.h:64:17: warning: array subscript 'volatile struct __xchg_dummy[0]' is partly outside array bounds of 'struct tcf_result[1]' [-Warray-bounds]
64 | __asm__ __volatile__
| ^~~~~~~
net/sched/cls_tcindex.c:338:27: note: while referencing 'cr'
338 | struct tcf_result cr = {};
| ^~
No binary output difference are seen from this change.
[1] commit 3364c6ce23c6 ("arm64: atomics: lse: Dereference matching size")
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/lkml/CAMuHMdVRrD+2zKoHxAaQdDuiK5JFDanbv0SJ91OdWfx+eyekPQ@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.
Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/lkml/87sfyzi97l.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
Explicitly zero select fields in the emulator's decode cache instead of
zeroing the fields via a gross memset() that spans six fields. gcc and
clang are both clever enough to batch the first five fields into a single
quadword MOV, i.e. memset() and individually zeroing generate identical
code.
Removing the wart also prepares KVM for FORTIFY_SOURCE performing
compile-time and run-time field bounds checking for memset().
No functional change intended.
Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/lkml/YR0jIEzEcUom/7rd@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
|
|
The SCMI binding clearly states the value of #thermal-sensor-cells must
be 1. However arch/arm64/boot/dts/freescale/imx8ulp.dtsi sets it 0 which
results in the following warning with dtbs_check:
| arch/arm64/boot/dts/freescale/imx8ulp-evk.dt.yaml: scmi:
| protocol@15:#thermal-sensor-cells:0:0: 1 was expected
| From schema: Documentation/devicetree/bindings/firmware/arm,scmi.yaml
Fix it by setting it to 1 as required.
Cc:Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
Fixes: a38771d7a49b ("arm64: dts: imx8ulp: add scmi firmware node")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
|
|
The vpumix power domain has a reset assigned to it, however
when used, it causes a system hang. Testing has shown that
it does not appear to be needed anywhere.
Fixes: d39d4bb15310 ("arm64: dts: imx8mm: add GPC node")
Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
|
|
amd-drm-next-5.18-2022-02-11-1:
amdgpu:
- Clean up of power management code
- Enable freesync video mode by default
- Clean up of RAS code
- Improve VRAM access for debug using SDMA
- Coding style cleanups
- SR-IOV fixes
- More display FP reorg
- TLB flush fixes for Arcuturus, Vega20
- Misc display fixes
- Rework special register access methods for SR-IOV
- DP2 fixes
- DP tunneling fixes
- DSC fixes
- More IP discovery cleanups
- Misc RAS fixes
- Enable both SMU i2c buses where applicable
- s2idle improvements
- DPCS header cleanup
- Add new CAP firmware support for SR-IOV
amdkfd:
- Misc cleanups
- SVM fixes
- CRIU support
- Clean up MQD manager
UAPI:
- Add interface to amdgpu CTX ioctl to request a stable power state for profiling
https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/207
- Add amdkfd support for CRIU
https://github.com/checkpoint-restore/criu/pull/1709
- Remove old unused amdkfd debugger interface
Was only implemented for Kaveri and was only ever used by an old HSA tool that was never open sourced
radeon:
- Fix error handling in radeon_driver_open_kms
- UVD suspend fix
- Misc fixes
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220211220706.5803-1-alexander.deucher@amd.com
|
|
nf_defrag_ipv6_disable() requires CONFIG_IP6_NF_IPTABLES.
Fixes: 75063c9294fb ("netfilter: xt_socket: fix a typo in socket_mt_destroy()")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Eric Dumazet<edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
|
|
It happens quite often that people use the wrong compiler to build the
kernel:
make ARCH=parisc -> builds the 32-bit kernel
make ARCH=parisc64 -> builds the 64-bit kernel
This patch adds a sanity check which errors out with an instruction how
use the correct ARCH= option.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.15+
|
|
The AXP288's recommended and factory default Vhold value (minimum
input voltage below which the input current draw will be reduced)
is 4.4V. This lines up with other charger IC's such as the TI
bq2419x/bq2429x series which use 4.36V or 4.44V.
For some reason some BIOS-es initialize Vhold to 4.6V or even 4.7V
which combined with the typical voltage drop over typically low
wire gauge micro-USB cables leads to the input-current getting
capped below 1A (with a 2A capable dedicated charger) based on Vhold.
This leads to slow charging, or even to the device slowly discharging
if the device is in heavy use.
As the Linux AXP288 drivers use the builtin BC1.2 charger detection
and send the input-current-limit according to the detected charger
there really is no reason not to use the recommended 4.4V Vhold.
Set Vhold to 4.4V to fix the slow charging issue on various devices.
There is one exception, the special-case of the HP X2 2-in-1s which
combine this BC1.2 capable PMIC with a Type-C port and a 5V/3A factory
provided charger with a Type-C plug which does not do BC1.2. These
have their input-current-limit hardcoded to 3A (like under Windows)
and use a higher Vhold on purpose to limit the current when used
with other chargers. To avoid touching Vhold on these HP X2 laptops
the code setting Vhold is added to an else branch of the if checking
for these models.
Note this also fixes the sofar unused VBUS_ISPOUT_VHOLD_SET_MASK
define, which was wrong.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
|
|
Remove unneeded variable used to store return value.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
|
Dmitry Torokhov
Angela Czubak
Tvrtko Ursulin
Jani Nikula
Halil Pasic
Yu Huang
Matteo Martelli
Thomas Zimmermann
Greg Kroah-Hartman
Christian Brauner
Al Viro
Christophe Leroy
Elliot Berman
Masahiro Yamada
Dave Airlie
Kees Cook
Sean Christopherson
Sudeep Holla
Adam Ford
Pablo Neira Ayuso
Helge Deller
Hans de Goede
Changcheng Deng