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commit 08389d888287c3823f80b0216766b71e17f0aba5 upstream.
Add a kconfig knob which allows for unprivileged bpf to be disabled by default.
If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2.
This still allows a transition of 2 -> {0,1} through an admin. Similarly,
this also still keeps 1 -> {1} behavior intact, so that once set to permanently
disabled, it cannot be undone aside from a reboot.
We've also added extra2 with max of 2 for the procfs handler, so that an admin
still has a chance to toggle between 0 <-> 2.
Either way, as an additional alternative, applications can make use of CAP_BPF
that we added a while ago.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net
[fllinden@amazon.com: backported to 4.9]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b1bd5cba3306691c771d558e94baa73e8b0b96b7 upstream.
When computing the access permissions of a shadow page, use the effective
permissions of the walk up to that point, i.e. the logic AND of its parents'
permissions. Two guest PxE entries that point at the same table gfn need to
be shadowed with different shadow pages if their parents' permissions are
different. KVM currently uses the effective permissions of the last
non-leaf entry for all non-leaf entries. Because all non-leaf SPTEs have
full ("uwx") permissions, and the effective permissions are recorded only
in role.access and merged into the leaves, this can lead to incorrect
reuse of a shadow page and eventually to a missing guest protection page
fault.
For example, here is a shared pagetable:
pgd[] pud[] pmd[] virtual address pointers
/->pmd1(u--)->pte1(uw-)->page1 <- ptr1 (u--)
/->pud1(uw-)--->pmd2(uw-)->pte2(uw-)->page2 <- ptr2 (uw-)
pgd-| (shared pmd[] as above)
\->pud2(u--)--->pmd1(u--)->pte1(uw-)->page1 <- ptr3 (u--)
\->pmd2(uw-)->pte2(uw-)->page2 <- ptr4 (u--)
pud1 and pud2 point to the same pmd table, so:
- ptr1 and ptr3 points to the same page.
- ptr2 and ptr4 points to the same page.
(pud1 and pud2 here are pud entries, while pmd1 and pmd2 here are pmd entries)
- First, the guest reads from ptr1 first and KVM prepares a shadow
page table with role.access=u--, from ptr1's pud1 and ptr1's pmd1.
"u--" comes from the effective permissions of pgd, pud1 and
pmd1, which are stored in pt->access. "u--" is used also to get
the pagetable for pud1, instead of "uw-".
- Then the guest writes to ptr2 and KVM reuses pud1 which is present.
The hypervisor set up a shadow page for ptr2 with pt->access is "uw-"
even though the pud1 pmd (because of the incorrect argument to
kvm_mmu_get_page in the previous step) has role.access="u--".
- Then the guest reads from ptr3. The hypervisor reuses pud1's
shadow pmd for pud2, because both use "u--" for their permissions.
Thus, the shadow pmd already includes entries for both pmd1 and pmd2.
- At last, the guest writes to ptr4. This causes no vmexit or pagefault,
because pud1's shadow page structures included an "uw-" page even though
its role.access was "u--".
Any kind of shared pagetable might have the similar problem when in
virtual machine without TDP enabled if the permissions are different
from different ancestors.
In order to fix the problem, we change pt->access to be an array, and
any access in it will not include permissions ANDed from child ptes.
The test code is: https://lore.kernel.org/kvm/20210603050537.19605-1-jiangshanlai@gmail.com/
Remember to test it with TDP disabled.
The problem had existed long before the commit 41074d07c78b ("KVM: MMU:
Fix inherited permissions for emulated guest pte updates"), and it
is hard to find which is the culprit. So there is no fixes tag here.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20210603052455.21023-1-jiangshanlai@gmail.com>
Cc: stable@vger.kernel.org
Fixes: cea0f0e7ea54 ("[PATCH] KVM: MMU: Shadow page table caching")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 4.9:
- Keep passing vcpu argument to gpte_access functions
- Adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit cd9e61ed1eebbcd5dfad59475d41ec58d9b64b6a upstream.
Patch series "rbtree: Cache leftmost node internally", v4.
A series to extending rbtrees to internally cache the leftmost node such
that we can have fast overlap check optimization for all interval tree
users[1]. The benefits of this series are that:
(i) Unify users that do internal leftmost node caching.
(ii) Optimize all interval tree users.
(iii) Convert at least two new users (epoll and procfs) to the new interface.
This patch (of 16):
Red-black tree semantics imply that nodes with smaller or greater (or
equal for duplicates) keys always be to the left and right,
respectively. For the kernel this is extremely evident when considering
our rb_first() semantics. Enabling lookups for the smallest node in the
tree in O(1) can save a good chunk of cycles in not having to walk down
the tree each time. To this end there are a few core users that
explicitly do this, such as the scheduler and rtmutexes. There is also
the desire for interval trees to have this optimization allowing faster
overlap checking.
This patch introduces a new 'struct rb_root_cached' which is just the
root with a cached pointer to the leftmost node. The reason why the
regular rb_root was not extended instead of adding a new structure was
that this allows the user to have the choice between memory footprint
and actual tree performance. The new wrappers on top of the regular
rb_root calls are:
- rb_first_cached(cached_root) -- which is a fast replacement
for rb_first.
- rb_insert_color_cached(node, cached_root, new)
- rb_erase_cached(node, cached_root)
In addition, augmented cached interfaces are also added for basic
insertion and deletion operations; which becomes important for the
interval tree changes.
With the exception of the inserts, which adds a bool for updating the
new leftmost, the interfaces are kept the same. To this end, porting rb
users to the cached version becomes really trivial, and keeping current
rbtree semantics for users that don't care about the optimization
requires zero overhead.
Link: http://lkml.kernel.org/r/20170719014603.19029-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 1c15b05baea71a5ff98235783e3e4ad227760876 ]
When 802.3ad bond mode is configured the ad_actor_system option is set to
"00:00:00:00:00:00". But when trying to set the all-zeroes MAC as actors'
system address it was failing with EINVAL.
An all-zeroes ethernet address is valid, only multicast addresses are not
valid values.
Fixes: 171a42c38c6e ("bonding: add netlink support for sys prio, actor sys mac, and port key")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Link: https://lore.kernel.org/r/20211221111345.2462-1-ffmancera@riseup.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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s5m8767,pmic-buck-default-dvs-idx property
commit a7fda04bc9b6ad9da8e19c9e6e3b1dab773d068a upstream.
The driver was always parsing "s5m8767,pmic-buck-default-dvs-idx", not
"s5m8767,pmic-buck234-default-dvs-idx".
Cc: <stable@vger.kernel.org>
Fixes: 26aec009f6b6 ("regulator: add device tree support for s5m8767")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Rob Herring <robh@kernel.org>
Message-Id: <20211008113723.134648-3-krzysztof.kozlowski@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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disabled
commit b16bef60a9112b1e6daf3afd16484eb06e7ce792 upstream.
The driver and its bindings, before commit 04f9f068a619 ("regulator:
s5m8767: Modify parsing method of the voltage table of buck2/3/4") were
requiring to provide at least one safe/default voltage for DVS registers
if DVS GPIO is not being enabled.
IOW, if s5m8767,pmic-buck2-uses-gpio-dvs is missing, the
s5m8767,pmic-buck2-dvs-voltage should still be present and contain one
voltage.
This requirement was coming from driver behavior matching this condition
(none of DVS GPIO is enabled): it was always initializing the DVS
selector pins to 0 and keeping the DVS enable setting at reset value
(enabled). Therefore if none of DVS GPIO is enabled in devicetree,
driver was configuring the first DVS voltage for buck[234].
Mentioned commit 04f9f068a619 ("regulator: s5m8767: Modify parsing
method of the voltage table of buck2/3/4") broke it because DVS voltage
won't be parsed from devicetree if DVS GPIO is not enabled. After the
change, driver will configure bucks to use the register reset value as
voltage which might have unpleasant effects.
Fix this by relaxing the bindings constrain: if DVS GPIO is not enabled
in devicetree (therefore DVS voltage is also not parsed), explicitly
disable it.
Cc: <stable@vger.kernel.org>
Fixes: 04f9f068a619 ("regulator: s5m8767: Modify parsing method of the voltage table of buck2/3/4")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Rob Herring <robh@kernel.org>
Message-Id: <20211008113723.134648-2-krzysztof.kozlowski@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 778cb8e39f6ec252be50fc3850d66f3dcbd5dd5a ]
"PAGESIZE / 512" is the number of ECC chunks.
"ECC_BYTES" is the number of bytes needed to store a single ECC code.
"2" is the space reserved by the bad block marker.
"2 + (PAGESIZE / 512) * ECC_BYTES" should of course be lower or equal
than the total number of OOB bytes, otherwise it won't fit.
Fix the equation by substituting s/>=/<=/.
Suggested-by: Ryan J. Barnett <ryan.barnett@collins.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20210610143945.3504781-1-miquel.raynal@bootlin.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit df2474a22c42ce419b67067c52d71da06c385501 ]
Since 9e8925b67a ("locks: Allow disabling mandatory locking at compile
time"), attempts to mount filesystems with "-o mand" will fail.
Unfortunately, there is no other indiciation of the reason for the
failure.
Change how the function is defined for better readability. When
CONFIG_MANDATORY_FILE_LOCKING is disabled, printk a warning when
someone attempts to mount with -o mand.
Also, add a blurb to the mandatory-locking.txt file to explain about
the "mand" option, and the behavior one should expect when it is
disabled.
Reported-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit c25ce589dca10d64dde139ae093abc258a32869c upstream.
Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.
Signed-off-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nicolas@fjasle.eu: update contexts for v4.9, adapt for old scripts]
Signed-off-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2efc459d06f1630001e3984854848a5647086232 upstream.
Output defects can exist in sysfs content using sprintf and snprintf.
sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.
Add a generic sysfs_emit function that knows that the size of the
temporary buffer and ensures that no overrun is done.
Add a generic sysfs_emit_at function that can be used in multiple
call situations that also ensures that no overrun is done.
Validate the output buffer argument to be page aligned.
Validate the offset len argument to be within the PAGE_SIZE buf.
Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/884235202216d464d61ee975f7465332c86f76b2.1600285923.git.joe@perches.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 4d521943f76bd0d1e68ea5e02df7aadd30b2838a ]
GPIO_ACTIVE_x flags are not correct in the context of interrupt flags.
These are simple defines so they could be used in DTS but they will not
have the same meaning:
1. GPIO_ACTIVE_HIGH = 0 = IRQ_TYPE_NONE
2. GPIO_ACTIVE_LOW = 1 = IRQ_TYPE_EDGE_RISING
Correct the interrupt flags, assuming the author of the code wanted same
logical behavior behind the name "ACTIVE_xxx", this is:
ACTIVE_LOW => IRQ_TYPE_LEVEL_LOW
ACTIVE_HIGH => IRQ_TYPE_LEVEL_HIGH
Fixes: a1a8b4594f8d ("NFC: pn544: i2c: Add DTS Documentation")
Fixes: 6be88670fc59 ("NFC: nxp-nci_i2c: Add I2C support to NXP NCI driver")
Fixes: e3b329221567 ("dt-bindings: can: tcan4x5x: Update binding to use interrupt property")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for tcan4x5x.txt
Link: https://lore.kernel.org/r/20201026153620.89268-1-krzk@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream.
IBM Power9 processors can speculatively operate on data in the L1 cache before
it has been completely validated, via a way-prediction mechanism. It is not possible
for an attacker to determine the contents of impermissible memory using this method,
since these systems implement a combination of hardware and software security measures
to prevent scenarios where protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that the
attacker controls. This can be used for example to speculatively bypass "kernel
user access prevention" techniques, as discovered by Anthony Steinhauser of
Google's Safeside Project. This is not an attack by itself, but there is a possibility
it could be used in conjunction with side-channels or other weaknesses in the
privileged code to construct an attack.
This issue can be mitigated by flushing the L1 cache between privilege boundaries
of concern. This patch flushes the L1 cache after user accesses.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream.
IBM Power9 processors can speculatively operate on data in the L1 cache before
it has been completely validated, via a way-prediction mechanism. It is not possible
for an attacker to determine the contents of impermissible memory using this method,
since these systems implement a combination of hardware and software security measures
to prevent scenarios where protected data could be leaked.
However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that the
attacker controls. This can be used for example to speculatively bypass "kernel
user access prevention" techniques, as discovered by Anthony Steinhauser of
Google's Safeside Project. This is not an attack by itself, but there is a possibility
it could be used in conjunction with side-channels or other weaknesses in the
privileged code to construct an attack.
This issue can be mitigated by flushing the L1 cache between privilege boundaries
of concern. This patch flushes the L1 cache on kernel entry.
This is part of the fix for CVE-2020-4788.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e99502f76271d6bc4e374fe368c50c67a1fd3070 upstream.
In case rogue guests are sending events at high frequency it might
happen that xen_evtchn_do_upcall() won't stop processing events in
dom0. As this is done in irq handling a crash might be the result.
In order to avoid that, delay further inter-domain events after some
time in xen_evtchn_do_upcall() by forcing eoi processing into a
worker on the same cpu, thus inhibiting new events coming in.
The time after which eoi processing is to be delayed is configurable
via a new module parameter "event_loop_timeout" which specifies the
maximum event loop time in jiffies (default: 2, the value was chosen
after some tests showing that a value of 2 was the lowest with an
only slight drop of dom0 network throughput while multiple guests
performed an event storm).
How long eoi processing will be delayed can be specified via another
parameter "event_eoi_delay" (again in jiffies, default 10, again the
value was chosen after testing with different delay values).
This is part of XSA-332.
Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Wei Liu <wl@xen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b38e7819cae946e2edf869e604af1e65a5d241c5 ]
Keyu Man reported that the ICMP rate limiter could be used
by attackers to get useful signal. Details will be provided
in an upcoming academic publication.
Our solution is to add some noise, so that the attackers
no longer can get help from the predictable token bucket limiter.
Fixes: 4cdf507d5452 ("icmp: add a global rate limitation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 95364f36701e62dd50eee91e1303187fd1a9f567 upstream.
In case a driver wants to return an error from qc_prep, return enum
ata_completion_errors. sata_mv is one of those drivers -- see the next
patch. Other drivers return the newly defined AC_ERR_OK.
[v2] use enum ata_completion_errors and AC_ERR_OK.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-ide@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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implementaion
[ Upstream commit 8c149b7d75e53be47648742f40fc90d9fc6fa63a ]
The required supplies in bindings were actually not matching
implementation making the bindings incorrect and misleading. The Linux
kernel driver requires all supplies to be present. Also for wlf,wm8994
uses just DBVDD-supply instead of DBVDDn-supply (n: <1,3>).
Reported-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200501133534.6706-1-krzk@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d3a84a8d0dde4e26bc084b36ffcbdc5932ac85e2 ]
The basic permission bits (protection bits in AmigaOS) have been broken
in Linux' AFFS - it would only set bits, but never delete them.
Also, contrary to the documentation, the Archived bit was not handled.
Let's fix this for good, and set the bits such that Linux and classic
AmigaOS can coexist in the most peaceful manner.
Also, update the documentation to represent the current state of things.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Max Staudt <max@enpas.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit df16c33a4028159d1ba8a7061c9fa950b58d1a61 ]
IIO_CONCENTRATION together with INFO_RAW specifier is used for reporting
raw concentrations of pollutants. Raw value should be meaningless
before being properly scaled. Because of that description shouldn't
mention raw value unit whatsoever.
Fix this by rephrasing existing description so it follows conventions
used throughout IIO ABI docs.
Fixes: 8ff6b3bc94930 ("iio: chemical: Add IIO_CONCENTRATION channel type")
Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 259a41d9ae8f3689742267f340ad2b159d00b302 upstream
There are several problems with regards to the return of
FE_SET_PROPERTY. The original idea were to return per-property
return codes via tvp->result field, and to return an updated
set of values.
However, that never worked. What's actually implemented is:
- the FE_SET_PROPERTY implementation doesn't call .get_frontend
callback in order to get the actual parameters after return;
- the tvp->result field is only filled if there's no error.
So, it is always filled with zero;
- FE_SET_PROPERTY doesn't call memdup_user() nor any other
copy_to_user() function. So, any changes to the properties
will be lost;
- FE_SET_PROPERTY is declared as a write-only ioctl (IOW).
While we could fix the above, it could cause regressions.
So, let's just assume what the code really does, updating
the documentation accordingly and removing the logic that
would update the discarded tvp->result.
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b0ff9b590733079f7f9453e5976a9dd2630949e3 ]
Add property "pinctrl-names" to swap pin mode between gpio and dpi mode.
Set the dpi pins to gpio mode and output-low to avoid leakage current
when dpi disabled.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit f7d31e65368aeef973fab788aa22c4f1d5a6af66 ]
The problem the patch is trying to address is the fact that 'struct
kvm_hyperv_exit' has different layout on when compiling in 32 and 64 bit
modes.
In 64-bit mode the default alignment boundary is 64 bits thus
forcing extra gaps after 'type' and 'msr' but in 32-bit mode the
boundary is at 32 bits thus no extra gaps.
This is an issue as even when the kernel is 64 bit, the userspace using
the interface can be both 32 and 64 bit but the same 32 bit userspace has
to work with 32 bit kernel.
The issue is fixed by forcing the 64 bit layout, this leads to ABI
change for 32 bit builds and while we are obviously breaking '32 bit
userspace with 32 bit kernel' case, we're fixing the '32 bit userspace
with 64 bit kernel' one.
As the interface has no (known) users and 32 bit KVM is rather baroque
nowadays, this seems like a reasonable decision.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424113746.3473563-2-arilou@gmail.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 3798cc4d106e91382bfe016caa2edada27c2bb3f upstream
Make the docs match the code.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7222a1b5b87417f22265c92deea76a6aecd0fb0f upstream
Add documentation for the SRBDS vulnerability and its mitigation.
[ bp: Massage.
jpoimboe: sysfs table strings. ]
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7e5b3c267d256822407a22fdce6afdf9cd13f9fb upstream
SRBDS is an MDS-like speculative side channel that can leak bits from the
random number generator (RNG) across cores and threads. New microcode
serializes the processor access during the execution of RDRAND and
RDSEED. This ensures that the shared buffer is overwritten before it is
released for reuse.
While it is present on all affected CPU models, the microcode mitigation
is not needed on models that enumerate ARCH_CAPABILITIES[MDS_NO] in the
cases where TSX is not supported or has been disabled with TSX_CTRL.
The mitigation is activated by default on affected processors and it
increases latency for RDRAND and RDSEED instructions. Among other
effects this will reduce throughput from /dev/urandom.
* Enable administrator to configure the mitigation off when desired using
either mitigations=off or srbds=off.
* Export vulnerability status via sysfs
* Rename file-scoped macros to apply for non-whitelist table initializations.
[ bp: Massage,
- s/VULNBL_INTEL_STEPPING/VULNBL_INTEL_STEPPINGS/g,
- do not read arch cap MSR a second time in tsx_fused_off() - just pass it in,
- flip check in cpu_set_bug_bits() to save an indentation level,
- reflow comments.
jpoimboe: s/Mitigated/Mitigation/ in user-visible strings
tglx: Dropped the fused off magic for now
]
Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 47c3e7783be4e142b861d34b5c2e223330b05d8a upstream.
PPPOL2TP_MSG_* and L2TP_MSG_* are duplicates, and are being used
interchangeably in the kernel, so let's standardize on L2TP_MSG_*
internally, and keep PPPOL2TP_MSG_* defined in UAPI for compatibility.
Signed-off-by: Asbjoern Sloth Toennesen <asbjorn@asbjorn.st>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Giuliano Procida <gprocida@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 26d5bb9e4c4b541c475751e015072eb2cbf70d15 ]
FMAN DMA read or writes under heavy traffic load may cause FMAN
internal resource leak; thus stopping further packet processing.
The FMAN internal queue can overflow when FMAN splits single
read or write transactions into multiple smaller transactions
such that more than 17 AXI transactions are in flight from FMAN
to interconnect. When the FMAN internal queue overflows, it can
stall further packet processing. The issue can occur with any one
of the following three conditions:
1. FMAN AXI transaction crosses 4K address boundary (Errata
A010022)
2. FMAN DMA address for an AXI transaction is not 16 byte
aligned, i.e. the last 4 bits of an address are non-zero
3. Scatter Gather (SG) frames have more than one SG buffer in
the SG list and any one of the buffers, except the last
buffer in the SG list has data size that is not a multiple
of 16 bytes, i.e., other than 16, 32, 48, 64, etc.
With any one of the above three conditions present, there is
likelihood of stalled FMAN packet processing, especially under
stress with multiple ports injecting line-rate traffic.
To avoid situations that stall FMAN packet processing, all of the
above three conditions must be avoided; therefore, configure the
system with the following rules:
1. Frame buffers must not span a 4KB address boundary, unless
the frame start address is 256 byte aligned
2. All FMAN DMA start addresses (for example, BMAN buffer
address, FD[address] + FD[offset]) are 16B aligned
3. SG table and buffer addresses are 16B aligned and the size
of SG buffers are multiple of 16 bytes, except for the last
SG buffer that can be of any size.
Additional workaround notes:
- Address alignment of 64 bytes is recommended for maximally
efficient system bus transactions (although 16 byte alignment is
sufficient to avoid the stall condition)
- To support frame sizes that are larger than 4K bytes, there are
two options:
1. Large single buffer frames that span a 4KB page boundary can
be converted into SG frames to avoid transaction splits at
the 4KB boundary,
2. Align the large single buffer to 256B address boundaries,
ensure that the frame address plus offset is 256B aligned.
- If software generated SG frames have buffers that are unaligned
and with random non-multiple of 16 byte lengths, before
transmitting such frames via FMAN, frames will need to be copied
into a new single buffer or multiple buffer SG frame that is
compliant with the three rules listed above.
Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3f9e12e0df012c4a9a7fd7eb0d3ae69b459d6b2c ]
In case the WDAT interface is broken, give the user an option to
ignore it to let a native driver bind to the watchdog device instead.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit d9a9f4849fe0c9d560851ab22a85a666cddfdd24 upstream.
several iterations of ->atomic_open() calling conventions ago, we
used to need fput() if ->atomic_open() failed at some point after
successful finish_open(). Now (since 2016) it's not needed -
struct file carries enough state to make fput() work regardless
of the point in struct file lifecycle and discarding it on
failure exits in open() got unified. Unfortunately, I'd missed
the fact that we had an instance of ->atomic_open() (cifs one)
that used to need that fput(), as well as the stale comment in
finish_open() demanding such late failure handling. Trivially
fixed...
Fixes: fe9ec8291fca "do_last(): take fput() on error after opening to out:"
Cc: stable@kernel.org # v4.7+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit de19055564c8f8f9d366f8db3395836da0b2176c upstream.
For a while Arm64 has been capable of force enabling
or disabling the kpti mitigations. Lets make sure the
documentation reflects that.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
[florian: patch the correct file]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 73668309215285366c433489de70d31362987be9 upstream.
mei client bus added the client protocol version to the device alias,
but ABI documentation was not updated.
Fixes: b26864cad1c9 (mei: bus: add client protocol version to the device alias)
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20191008005735.12707-1-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 73852e56827f5cb5db9d6e8dd8191fc2f2e8f424 ]
The abracon,tc-resistor property value is in kOhm.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 46b14eef59a8157138dc02f916a7f97c73b3ec53 ]
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 64870ed1b12e235cfca3f6c6da75b542c973ff78 upstream.
For MDS vulnerable processors with TSX support, enabling either MDS or
TAA mitigations will enable the use of VERW to flush internal processor
buffers at the right code path. IOW, they are either both mitigated
or both not. However, if the command line options are inconsistent,
the vulnerabilites sysfs files may not report the mitigation status
correctly.
For example, with only the "mds=off" option:
vulnerabilities/mds:Vulnerable; SMT vulnerable
vulnerabilities/tsx_async_abort:Mitigation: Clear CPU buffers; SMT vulnerable
The mds vulnerabilities file has wrong status in this case. Similarly,
the taa vulnerability file will be wrong with mds mitigation on, but
taa off.
Change taa_select_mitigation() to sync up the two mitigation status
and have them turned off if both "mds=off" and "tsx_async_abort=off"
are present.
Update documentation to emphasize the fact that both "mds=off" and
"tsx_async_abort=off" have to be specified together for processors that
are affected by both TAA and MDS to be effective.
[ bp: Massage and add kernel-parameters.txt change too. ]
Fixes: 1b42f017415b ("x86/speculation/taa: Add mitigation for TSX Async Abort")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: Mark Gross <mgross@linux.intel.com>
Cc: <stable@vger.kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191115161445.30809-2-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7f00cc8d4a51074eb0ad4c3f16c15757b1ddfb7d upstream.
Add the initial ITLB_MULTIHIT documentation.
[ tglx: Add it to the index so it gets actually built. ]
Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Nelson D'Souza <nelson.dsouza@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9: adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1aa9b9572b10529c2e64e2b8f44025d86e124308 upstream.
The page table pages corresponding to broken down large pages are zapped in
FIFO order, so that the large page can potentially be recovered, if it is
not longer being used for execution. This removes the performance penalty
for walking deeper EPT page tables.
By default, one large page will last about one hour once the guest
reaches a steady state.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9:
- Update another error path in kvm_create_vm() to use out_err_no_mmu_notifier
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b8e8c8303ff28c61046a4d0f6ea99aea609a7dc0 upstream.
With some Intel processors, putting the same virtual address in the TLB
as both a 4 KiB and 2 MiB page can confuse the instruction fetch unit
and cause the processor to issue a machine check resulting in a CPU lockup.
Unfortunately when EPT page tables use huge pages, it is possible for a
malicious guest to cause this situation.
Add a knob to mark huge pages as non-executable. When the nx_huge_pages
parameter is enabled (and we are using EPT), all huge pages are marked as
NX. If the guest attempts to execute in one of those pages, the page is
broken down into 4K pages, which are then marked executable.
This is not an issue for shadow paging (except nested EPT), because then
the host is in control of TLB flushes and the problematic situation cannot
happen. With nested EPT, again the nested guest can cause problems shadow
and direct EPT is treated in the same way.
[ tglx: Fixup default to auto and massage wording a bit ]
Originally-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9:
- Use kvm_mmu_invalidate_zap_all_pages() instead of kvm_mmu_zap_all_fast()
- Don't provide mode for nx_largepages_splitted as all stats are read-only
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream.
Some processors may incur a machine check error possibly resulting in an
unrecoverable CPU lockup when an instruction fetch encounters a TLB
multi-hit in the instruction TLB. This can occur when the page size is
changed along with either the physical address or cache type. The relevant
erratum can be found here:
https://bugzilla.kernel.org/show_bug.cgi?id=205195
There are other processors affected for which the erratum does not fully
disclose the impact.
This issue affects both bare-metal x86 page tables and EPT.
It can be mitigated by either eliminating the use of large pages or by
using careful TLB invalidations when changing the page size in the page
tables.
Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in
MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which
are mitigated against this issue.
Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9:
- No support for X86_VENDOR_HYGON, ATOM_AIRMONT_NP
- Adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0d9ce162cf46c99628cc5da9510b959c7976735b upstream.
It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 4.9:
- Drop changes in kvm_hyperv_tsc_notifier(), vm_stat_clear(),
vcpu_stat_clear(), kvm_uevent_notify_change()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a7a248c593e4fd7a67c50b5f5318fe42a0db335e upstream.
Add the documenation for TSX Async Abort. Include the description of
the issue, how to check the mitigation state, control the mitigation,
guidance for system administrators.
[ bp: Add proper SPDX tags, touch ups by Josh and me. ]
Co-developed-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mark Gross <mgross@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.9: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream.
Platforms which are not affected by X86_BUG_TAA may want the TSX feature
enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto
disable TSX when X86_BUG_TAA is present, otherwise enable TSX.
More details on X86_BUG_TAA can be found here:
https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html
[ bp: Extend the arg buffer to accommodate "auto\0". ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 95c5824f75f3ba4c9e8e5a4b1a623c95390ac266 upstream.
Add a kernel cmdline parameter "tsx" to control the Transactional
Synchronization Extensions (TSX) feature. On CPUs that support TSX
control, use "tsx=on|off" to enable or disable TSX. Not specifying this
option is equivalent to "tsx=off". This is because on certain processors
TSX may be used as a part of a speculative side channel attack.
Carve out the TSX controlling functionality into a separate compilation
unit because TSX is a CPU feature while the TSX async abort control
machinery will go to cpu/bugs.c.
[ bp: - Massage, shorten and clear the arg buffer.
- Clarifications of the tsx= possible options - Josh.
- Expand on TSX_CTRL availability - Pawan. ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.9: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 015664d15270a112c2371d812f03f7c579b35a73 upstream.
The Rio500 kernel driver has not been used by Rio500 owners since 2001
not long after the rio500 project added support for a user-space USB stack
through the very first versions of usbdevfs and then libusb.
Support for the kernel driver was removed from the upstream utilities
in 2008:
https://gitlab.freedesktop.org/hadess/rio500/commit/943f624ab721eb8281c287650fcc9e2026f6f5db
Cc: Cesar Miquel <miquel@df.uba.ar>
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/6251c17584d220472ce882a3d9c199c401a51a71.camel@hadess.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit c49a0a80137c7ca7d6ced4c812c9e07a949f6f24 ]
There have been reports of RDRAND issues after resuming from suspend on
some AMD family 15h and family 16h systems. This issue stems from a BIOS
not performing the proper steps during resume to ensure RDRAND continues
to function properly.
RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be
reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND
support using CPUID, including the kernel, will believe that RDRAND is
not supported.
Update the CPU initialization to clear the RDRAND CPUID bit for any family
15h and 16h processor that supports RDRAND. If it is known that the family
15h or family 16h system does not have an RDRAND resume issue or that the
system will not be placed in suspend, the "rdrand=force" kernel parameter
can be used to stop the clearing of the RDRAND CPUID bit.
Additionally, update the suspend and resume path to save and restore the
MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in
place after resuming from suspend.
Note, that clearing the RDRAND CPUID bit does not prevent a processor
that normally supports the RDRAND instruction from executing it. So any
code that determined the support based on family and model won't #UD.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chen Yu <yu.c.chen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
[sl: adjust context in docs]
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1 upstream.
HalfSipHash, or hsiphash, is a shortened version of SipHash, which
generates 32-bit outputs using a weaker 64-bit key. It has *much* lower
security margins, and shouldn't be used for anything too sensitive, but
it could be used as a hashtable key function replacement, if the output
is never exposed, and if the security requirement is not too high.
The goal is to make this something that performance-critical jhash users
would be willing to use.
On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias
SipHash1-3 to HalfSipHash1-3 on those systems.
64-bit x86_64:
[ 0.509409] test_siphash: SipHash2-4 cycles: 4049181
[ 0.510650] test_siphash: SipHash1-3 cycles: 2512884
[ 0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920
[ 0.512904] test_siphash: JenkinsHash cycles: 978267
So, we map hsiphash() -> SipHash1-3
32-bit x86:
[ 0.509868] test_siphash: SipHash2-4 cycles: 14812892
[ 0.513601] test_siphash: SipHash1-3 cycles: 9510710
[ 0.515263] test_siphash: HalfSipHash1-3 cycles: 3856157
[ 0.515952] test_siphash: JenkinsHash cycles: 1148567
So, we map hsiphash() -> HalfSipHash1-3
hsiphash() is roughly 3 times slower than jhash(), but comes with a
considerable security improvement.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.9 to avoid regression for WireGuard with only half
the siphash API present]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2c956a60778cbb6a27e0c7a8a52a91378c90e1d1 upstream.
SipHash is a 64-bit keyed hash function that is actually a
cryptographically secure PRF, like HMAC. Except SipHash is super fast,
and is meant to be used as a hashtable keyed lookup function, or as a
general PRF for short input use cases, such as sequence numbers or RNG
chaining.
For the first usage:
There are a variety of attacks known as "hashtable poisoning" in which an
attacker forms some data such that the hash of that data will be the
same, and then preceeds to fill up all entries of a hashbucket. This is
a realistic and well-known denial-of-service vector. Currently
hashtables use jhash, which is fast but not secure, and some kind of
rotating key scheme (or none at all, which isn't good). SipHash is meant
as a replacement for jhash in these cases.
There are a modicum of places in the kernel that are vulnerable to
hashtable poisoning attacks, either via userspace vectors or network
vectors, and there's not a reliable mechanism inside the kernel at the
moment to fix it. The first step toward fixing these issues is actually
getting a secure primitive into the kernel for developers to use. Then
we can, bit by bit, port things over to it as deemed appropriate.
While SipHash is extremely fast for a cryptographically secure function,
it is likely a bit slower than the insecure jhash, and so replacements
will be evaluated on a case-by-case basis based on whether or not the
difference in speed is negligible and whether or not the current jhash usage
poses a real security risk.
For the second usage:
A few places in the kernel are using MD5 or SHA1 for creating secure
sequence numbers, syn cookies, port numbers, or fast random numbers.
SipHash is a faster and more fitting, and more secure replacement for MD5
in those situations. Replacing MD5 and SHA1 with SipHash for these uses is
obvious and straight-forward, and so is submitted along with this patch
series. There shouldn't be much of a debate over its efficacy.
Dozens of languages are already using this internally for their hash
tables and PRFs. Some of the BSDs already use this in their kernels.
SipHash is a widely known high-speed solution to a widely known set of
problems, and it's time we catch-up.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.9 as dependency of commits df453700e8d8 "inet: switch
IP ID generator to siphash" and 3c79107631db "netfilter: ctnetlink: don't
use conntrack/expect object addresses as id"]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ede95a63b5e84ddeea6b0c473b36ab8bfd8c6ce3 upstream.
Rick reported that the BPF JIT could potentially fill the entire module
space with BPF programs from unprivileged users which would prevent later
attempts to load normal kernel modules or privileged BPF programs, for
example. If JIT was enabled but unsuccessful to generate the image, then
before commit 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config")
we would always fall back to the BPF interpreter. Nowadays in the case
where the CONFIG_BPF_JIT_ALWAYS_ON could be set, then the load will abort
with a failure since the BPF interpreter was compiled out.
Add a global limit and enforce it for unprivileged users such that in case
of BPF interpreter compiled out we fail once the limit has been reached
or we fall back to BPF interpreter earlier w/o using module mem if latter
was compiled in. In a next step, fair share among unprivileged users can
be resolved in particular for the case where we would fail hard once limit
is reached.
Fixes: 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config")
Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64")
Co-Developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a2059825986a1c8143fd6698774fa9d83733bb11 upstream.
The previous commit added macro calls in the entry code which mitigate the
Spectre v1 swapgs issue if the X86_FEATURE_FENCE_SWAPGS_* features are
enabled. Enable those features where applicable.
The mitigations may be disabled with "nospectre_v1" or "mitigations=off".
There are different features which can affect the risk of attack:
- When FSGSBASE is enabled, unprivileged users are able to place any
value in GS, using the wrgsbase instruction. This means they can
write a GS value which points to any value in kernel space, which can
be useful with the following gadget in an interrupt/exception/NMI
handler:
if (coming from user space)
swapgs
mov %gs:<percpu_offset>, %reg1
// dependent load or store based on the value of %reg
// for example: mov %(reg1), %reg2
If an interrupt is coming from user space, and the entry code
speculatively skips the swapgs (due to user branch mistraining), it
may speculatively execute the GS-based load and a subsequent dependent
load or store, exposing the kernel data to an L1 side channel leak.
Note that, on Intel, a similar attack exists in the above gadget when
coming from kernel space, if the swapgs gets speculatively executed to
switch back to the user GS. On AMD, this variant isn't possible
because swapgs is serializing with respect to future GS-based
accesses.
NOTE: The FSGSBASE patch set hasn't been merged yet, so the above case
doesn't exist quite yet.
- When FSGSBASE is disabled, the issue is mitigated somewhat because
unprivileged users must use prctl(ARCH_SET_GS) to set GS, which
restricts GS values to user space addresses only. That means the
gadget would need an additional step, since the target kernel address
needs to be read from user space first. Something like:
if (coming from user space)
swapgs
mov %gs:<percpu_offset>, %reg1
mov (%reg1), %reg2
// dependent load or store based on the value of %reg2
// for example: mov %(reg2), %reg3
It's difficult to audit for this gadget in all the handlers, so while
there are no known instances of it, it's entirely possible that it
exists somewhere (or could be introduced in the future). Without
tooling to analyze all such code paths, consider it vulnerable.
Effects of SMAP on the !FSGSBASE case:
- If SMAP is enabled, and the CPU reports RDCL_NO (i.e., not
susceptible to Meltdown), the kernel is prevented from speculatively
reading user space memory, even L1 cached values. This effectively
disables the !FSGSBASE attack vector.
- If SMAP is enabled, but the CPU *is* susceptible to Meltdown, SMAP
still prevents the kernel from speculatively reading user space
memory. But it does *not* prevent the kernel from reading the
user value from L1, if it has already been cached. This is probably
only a small hurdle for an attacker to overcome.
Thanks to Dave Hansen for contributing the speculative_smap() function.
Thanks to Andrew Cooper for providing the inside scoop on whether swapgs
is serializing on AMD.
[ tglx: Fixed the USER fence decision and polished the comment as suggested
by Dave Hansen ]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
[bwh: Backported to 4.9:
- Check for X86_FEATURE_KAISER instead of X86_FEATURE_PTI
- mitigations= parameter is x86-only here
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c737abc193d16e62e23e2fb585b8b7398ab380d8 upstream.
Armada-37xx UART0 registers are 0x200 bytes wide. Right next to them are
the UART1 registers that should not be declared in this node.
Update the example in DT bindings document accordingly.
Signed-off-by: allen yan <yanwei@marvell.com>
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 0df82dcd55832a99363ab7f9fab954fcacdac3ae ]
Fully compatible with mcp2515, the mcp25625 have integrated transceiver.
This patch add the mcp25625 to the device tree bindings documentation.
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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