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* Documentation: security-bugs.rst: clarify CVE handlingGreg Kroah-Hartman2023-08-111-7/+6
| | | | | | | | | | | | commit 3c1897ae4b6bc7cc586eda2feaa2cd68325ec29c upstream. The kernel security team does NOT assign CVEs, so document that properly and provide the "if you want one, ask MITRE for it" response that we give on a weekly basis in the document, so we don't have to constantly say it to everyone who asks. Link: https://lore.kernel.org/r/2023063022-retouch-kerosene-7e4a@gregkh Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Documentation: security-bugs.rst: update preferences when dealing with the ↵Greg Kroah-Hartman2023-08-111-14/+12
| | | | | | | | | | | | | | | | linux-distros group commit 4fee0915e649bd0cea56dece6d96f8f4643df33c upstream. Because the linux-distros group forces reporters to release information about reported bugs, and they impose arbitrary deadlines in having those bugs fixed despite not actually being kernel developers, the kernel security team recommends not interacting with them at all as this just causes confusion and the early-release of reported security problems. Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/2023063020-throat-pantyhose-f110@gregkh Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Documentation/x86: Fix backwards on/off logic about YMM supportDave Hansen2023-08-081-1/+1
| | | | | | | | | | | | commit 1b0fc0345f2852ffe54fb9ae0e12e2ee69ad6a20 upstream These options clearly turn *off* XSAVE YMM support. Correct the typo. Reported-by: Ben Hutchings <ben@decadent.org.uk> Fixes: 553a5c03e90a ("x86/speculation: Add force option to GDS mitigation") Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation: Add force option to GDS mitigationDaniel Sneddon2023-08-082-5/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 553a5c03e90a6087e88f8ff878335ef0621536fb upstream The Gather Data Sampling (GDS) vulnerability allows malicious software to infer stale data previously stored in vector registers. This may include sensitive data such as cryptographic keys. GDS is mitigated in microcode, and systems with up-to-date microcode are protected by default. However, any affected system that is running with older microcode will still be vulnerable to GDS attacks. Since the gather instructions used by the attacker are part of the AVX2 and AVX512 extensions, disabling these extensions prevents gather instructions from being executed, thereby mitigating the system from GDS. Disabling AVX2 is sufficient, but we don't have the granularity to do this. The XCR0[2] disables AVX, with no option to just disable AVX2. Add a kernel parameter gather_data_sampling=force that will enable the microcode mitigation if available, otherwise it will disable AVX on affected systems. This option will be ignored if cmdline mitigations=off. This is a *big* hammer. It is known to break buggy userspace that uses incomplete, buggy AVX enumeration. Unfortunately, such userspace does exist in the wild: https://www.mail-archive.com/bug-coreutils@gnu.org/msg33046.html [ dhansen: add some more ominous warnings about disabling AVX ] Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation: Add Gather Data Sampling mitigationDaniel Sneddon2023-08-084-14/+130
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8974eb588283b7d44a7c91fa09fcbaf380339f3a upstream Gather Data Sampling (GDS) is a hardware vulnerability which allows unprivileged speculative access to data which was previously stored in vector registers. Intel processors that support AVX2 and AVX512 have gather instructions that fetch non-contiguous data elements from memory. On vulnerable hardware, when a gather instruction is transiently executed and encounters a fault, stale data from architectural or internal vector registers may get transiently stored to the destination vector register allowing an attacker to infer the stale data using typical side channel techniques like cache timing attacks. This mitigation is different from many earlier ones for two reasons. First, it is enabled by default and a bit must be set to *DISABLE* it. This is the opposite of normal mitigation polarity. This means GDS can be mitigated simply by updating microcode and leaving the new control bit alone. Second, GDS has a "lock" bit. This lock bit is there because the mitigation affects the hardware security features KeyLocker and SGX. It needs to be enabled and *STAY* enabled for these features to be mitigated against GDS. The mitigation is enabled in the microcode by default. Disable it by setting gather_data_sampling=off or by disabling all mitigations with mitigations=off. The mitigation status can be checked by reading: /sys/devices/system/cpu/vulnerabilities/gather_data_sampling Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Remove DECnet support from kernelStephen Hemminger2023-06-214-238/+0
| | | | | | | | | | | | | | | | | | | | | | | | | commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream. DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: David Ahern <dsahern@kernel.org> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* media: uapi: add MEDIA_BUS_FMT_METADATA_FIXED media bus format.Dafna Hirschfeld2023-05-171-0/+27
| | | | | | | | | | | | | | | | | | [ Upstream commit 6ad253cc3436269fc6bcff03d704c672f368da0a ] MEDIA_BUS_FMT_METADATA_FIXED should be used when the same driver handles both sides of the link and the bus format is a fixed metadata format that is not configurable from userspace. The width and height will be set to 0 for this format. Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com> Acked-by: Helen Koike <helen.koike@collabora.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Stable-dep-of: eed9496a0501 ("media: av7110: prevent underflow in write_ts_to_decoder()") Signed-off-by: Sasha Levin <sashal@kernel.org>
* ALSA: hda/sigmatel: add pin overrides for Intel DP45SG motherboardOswald Buddenhagen2023-04-201-1/+1
| | | | | | | | | | | | | commit c17f8fd31700392b1bb9e7b66924333568cb3700 upstream. Like the other boards from the D*45* series, this one sets up the outputs not quite correctly. Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20230405201220.2197826-1-oswald.buddenhagen@gmx.de Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* intel-ethernet: rename i40evf to iavfJesse Brandeburg2023-04-052-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8062b2263a9fc294ddeb4024b113e8e26b82d5de ] Rename the Intel Ethernet Adaptive Virtual Function driver (i40evf) to a new name (iavf) that is more consistent with the ongoing maintenance of the driver as the universal VF driver for multiple product lines. This first patch fixes up the directory names and the .ko name, intentionally ignoring the function names inside the driver for now. Basically this is the simplest patch that gets the rename done and will be followed by other patches that rename the internal functions. This patch also addresses a couple of string/name issues and updates the Copyright year. Also, made sure to add a MODULE_ALIAS to the old name. Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Stable-dep-of: 32d57f667f87 ("iavf: fix inverted Rx hash condition leading to disabled hash") Signed-off-by: Sasha Levin <sashal@kernel.org>
* Documentation/hw-vuln: Document the interaction between IBRS and STIBPKP Singh2023-03-111-5/+16
| | | | | | | | | | | | | commit e02b50ca442e88122e1302d4dbc1b71a4808c13f upstream. Explain why STIBP is needed with legacy IBRS as currently implemented (KERNEL_IBRS) and why STIBP is not needed when enhanced IBRS is enabled. Fixes: 7c693f54c873 ("x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS") Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230227060541.1939092-2-kpsingh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* docs/scripts/gdb: add necessary make scripts_gdb stepJakob Koschel2023-03-111-0/+4
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 6b219431037bf98c9efd49716aea9b68440477a3 ] In order to debug the kernel successfully with gdb you need to run 'make scripts_gdb' nowadays. This was changed with the following commit: Commit 67274c083438340ad16c ("scripts/gdb: delay generation of gdb constants.py") In order to have a complete guide for beginners this remark should be added to the offial documentation. Signed-off-by: Jakob Koschel <jkl820.git@gmail.com> Link: https://lore.kernel.org/r/20230112-documentation-gdb-v2-1-292785c43dc9@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* docs: Fix path paste-o for /sys/kernel/warn_countKees Cook2023-02-061-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 00dd027f721e0458418f7750d8a5a664ed3e5994 upstream. Running "make htmldocs" shows that "/sys/kernel/oops_count" was duplicated. This should have been "warn_count": Warning: /sys/kernel/oops_count is defined 2 times: ./Documentation/ABI/testing/sysfs-kernel-warn_count:0 ./Documentation/ABI/testing/sysfs-kernel-oops_count:0 Fix the typo. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/linux-doc/202212110529.A3Qav8aR-lkp@intel.com Fixes: 8b05aa263361 ("panic: Expose "warn_count" to sysfs") Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* panic: Expose "warn_count" to sysfsKees Cook2023-02-061-0/+6
| | | | | | | | | | | | | | | | | | | commit 8b05aa26336113c4cea25f1c333ee8cd4fc212a6 upstream. Since Warn count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/warn_count to expose it to userspace. Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@chromium.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* panic: Introduce warn_limitKees Cook2023-02-061-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | commit 9fc9e278a5c0b708eeffaf47d6eb0c82aa74ed78 upstream. Like oops_limit, add warn_limit for limiting the number of warnings when panic_on_warn is not set. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Petr Mladek <pmladek@suse.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-5-keescook@chromium.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* exit: Allow oops_limit to be disabledKees Cook2023-02-061-2/+3
| | | | | | | | | | | | | | | | | | | | | commit de92f65719cd672f4b48397540b9f9eff67eca40 upstream. In preparation for keeping oops_limit logic in sync with warn_limit, have oops_limit == 0 disable checking the Oops counter. Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-doc@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* exit: Expose "oops_count" to sysfsKees Cook2023-02-061-0/+6
| | | | | | | | | | | | | | | | commit 9db89b41117024f80b38b15954017fb293133364 upstream. Since Oops count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/oops_count to expose it to userspace. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jann Horn <jannh@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* exit: Put an upper limit on how often we can oopsJann Horn2023-02-061-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d4ccd54d28d3c8598e2354acc13e28c060961dbb upstream. Many Linux systems are configured to not panic on oops; but allowing an attacker to oops the system **really** often can make even bugs that look completely unexploitable exploitable (like NULL dereferences and such) if each crash elevates a refcount by one or a lock is taken in read mode, and this causes a counter to eventually overflow. The most interesting counters for this are 32 bits wide (like open-coded refcounts that don't use refcount_t). (The ldsem reader count on 32-bit platforms is just 16 bits, but probably nobody cares about 32-bit platforms that much nowadays.) So let's panic the system if the kernel is constantly oopsing. The speed of oopsing 2^32 times probably depends on several factors, like how long the stack trace is and which unwinder you're using; an empirically important one is whether your console is showing a graphical environment or a text console that oopses will be printed to. In a quick single-threaded benchmark, it looks like oopsing in a vfork() child with a very short stack trace only takes ~510 microseconds per run when a graphical console is active; but switching to a text console that oopses are printed to slows it down around 87x, to ~45 milliseconds per run. (Adding more threads makes this faster, but the actual oops printing happens under &die_lock on x86, so you can maybe speed this up by a factor of around 2 and then any further improvement gets eaten up by lock contention.) It looks like it would take around 8-12 days to overflow a 32-bit counter with repeated oopsing on a multi-core X86 system running a graphical environment; both me (in an X86 VM) and Seth (with a distro kernel on normal hardware in a standard configuration) got numbers in that ballpark. 12 days aren't *that* short on a desktop system, and you'd likely need much longer on a typical server system (assuming that people don't run graphical desktop environments on their servers), and this is a *very* noisy and violent approach to exploiting the kernel; and it also seems to take orders of magnitude longer on some machines, probably because stuff like EFI pstore will slow it down a ton if that's active. Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20221107201317.324457-1-jannh@google.com Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-2-keescook@chromium.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* docs: Fix the docs build with Sphinx 6.0Jonathan Corbet2023-01-181-2/+4
| | | | | | | | | | | | | | | | commit 0283189e8f3d0917e2ac399688df85211f48447b upstream. Sphinx 6.0 removed the execfile_() function, which we use as part of the configuration process. They *did* warn us... Just open-code the functionality as is done in Sphinx itself. Tested (using SPHINX_CONF, since this code is only executed with an alternative config file) on various Sphinx versions from 2.5 through 6.0. Reported-by: Martin Liška <mliska@suse.cz> Cc: stable@vger.kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* spi: Update reference to struct spi_controllerJonathan Neuschäfer2023-01-181-2/+2
| | | | | | | | | | | | | [ Upstream commit bf585ccee22faf469d82727cf375868105b362f7 ] struct spi_master has been renamed to struct spi_controller. Update the reference in spi.rst to make it clickable again. Fixes: 8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"") Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Link: https://lore.kernel.org/r/20221101173252.1069294-1-j.neuschaefer@gmx.net Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* debugfs: fix error when writing negative value to atomic_t debugfs fileAkinobu Mita2023-01-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d472cf797c4e268613dbce5ec9b95d0bcae19ecb ] The simple attribute files do not accept a negative value since the commit 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()"), so we have to use a 64-bit value to write a negative value for a debugfs file created by debugfs_create_atomic_t(). This restores the previous behaviour by introducing DEFINE_DEBUGFS_ATTRIBUTE_SIGNED for a signed value. Link: https://lkml.kernel.org/r/20220919172418.45257-4-akinobu.mita@gmail.com Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reported-by: Zhao Gongyi <zhaogongyi@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Wei Yongjun <weiyongjun1@huawei.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* docs: update mediator contact information in CoC docShuah Khan2022-11-251-1/+1
| | | | | | | | | | | commit 5fddf8962b429b8303c4a654291ecb6e61a7d747 upstream. Update mediator contact information in CoC interpretation document. Cc: <stable@vger.kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/20221011171417.34286-1-skhan@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation: Add RSB VM Exit protectionsDaniel Sneddon2022-11-231-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream. tl;dr: The Enhanced IBRS mitigation for Spectre v2 does not work as documented for RET instructions after VM exits. Mitigate it with a new one-entry RSB stuffing mechanism and a new LFENCE. == Background == Indirect Branch Restricted Speculation (IBRS) was designed to help mitigate Branch Target Injection and Speculative Store Bypass, i.e. Spectre, attacks. IBRS prevents software run in less privileged modes from affecting branch prediction in more privileged modes. IBRS requires the MSR to be written on every privilege level change. To overcome some of the performance issues of IBRS, Enhanced IBRS was introduced. eIBRS is an "always on" IBRS, in other words, just turn it on once instead of writing the MSR on every privilege level change. When eIBRS is enabled, more privileged modes should be protected from less privileged modes, including protecting VMMs from guests. == Problem == Here's a simplification of how guests are run on Linux' KVM: void run_kvm_guest(void) { // Prepare to run guest VMRESUME(); // Clean up after guest runs } The execution flow for that would look something like this to the processor: 1. Host-side: call run_kvm_guest() 2. Host-side: VMRESUME 3. Guest runs, does "CALL guest_function" 4. VM exit, host runs again 5. Host might make some "cleanup" function calls 6. Host-side: RET from run_kvm_guest() Now, when back on the host, there are a couple of possible scenarios of post-guest activity the host needs to do before executing host code: * on pre-eIBRS hardware (legacy IBRS, or nothing at all), the RSB is not touched and Linux has to do a 32-entry stuffing. * on eIBRS hardware, VM exit with IBRS enabled, or restoring the host IBRS=1 shortly after VM exit, has a documented side effect of flushing the RSB except in this PBRSB situation where the software needs to stuff the last RSB entry "by hand". IOW, with eIBRS supported, host RET instructions should no longer be influenced by guest behavior after the host retires a single CALL instruction. However, if the RET instructions are "unbalanced" with CALLs after a VM exit as is the RET in #6, it might speculatively use the address for the instruction after the CALL in #3 as an RSB prediction. This is a problem since the (untrusted) guest controls this address. Balanced CALL/RET instruction pairs such as in step #5 are not affected. == Solution == The PBRSB issue affects a wide variety of Intel processors which support eIBRS. But not all of them need mitigation. Today, X86_FEATURE_RSB_VMEXIT triggers an RSB filling sequence that mitigates PBRSB. Systems setting RSB_VMEXIT need no further mitigation - i.e., eIBRS systems which enable legacy IBRS explicitly. However, such systems (X86_FEATURE_IBRS_ENHANCED) do not set RSB_VMEXIT and most of them need a new mitigation. Therefore, introduce a new feature flag X86_FEATURE_RSB_VMEXIT_LITE which triggers a lighter-weight PBRSB mitigation versus RSB_VMEXIT. The lighter-weight mitigation performs a CALL instruction which is immediately followed by a speculative execution barrier (INT3). This steers speculative execution to the barrier -- just like a retpoline -- which ensures that speculation can never reach an unbalanced RET. Then, ensure this CALL is retired before continuing execution with an LFENCE. In other words, the window of exposure is opened at VM exit where RET behavior is troublesome. While the window is open, force RSB predictions sampling for RET targets to a dead end at the INT3. Close the window with the LFENCE. There is a subset of eIBRS systems which are not vulnerable to PBRSB. Add these systems to the cpu_vuln_whitelist[] as NO_EIBRS_PBRSB. Future systems that aren't vulnerable will set ARCH_CAP_PBRSB_NO. [ bp: Massage, incorporate review comments from Andy Cooper. ] Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.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: Borislav Petkov <bp@suse.de> [ bp: Adjust patch to account for kvm entry being in c ] Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRSPawan Gupta2022-11-231-0/+1
| | | | | | | | | | | | | | | | | commit 7c693f54c873691a4b7da05c7e0f74e67745d144 upstream. Extend spectre_v2= boot option with Kernel IBRS. [jpoimboe: no STIBP with IBRS] Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/bugs: Add AMD retbleed= boot parameterAlexandre Chartre2022-11-231-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7fbf47c7ce50b38a64576b150e7011ae73d54669 upstream. Add the "retbleed=<value>" boot parameter to select a mitigation for RETBleed. Possible values are "off", "auto" and "unret" (JMP2RET mitigation). The default value is "auto". Currently, "retbleed=auto" will select the unret mitigation on AMD and Hygon and no mitigation on Intel (JMP2RET is not effective on Intel). [peterz: rebase; add hygon] [jpoimboe: cleanups] Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> [cascardo: this effectively remove the UNRET mitigation as an option, so it has to be complemented by a later pick of the same commit later. This is done in order to pick retbleed_select_mitigation] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "x86/speculation: Add RSB VM Exit protections"Suleiman Souhlal2022-11-231-8/+0
| | | | | | | | | | | This reverts commit b6c5011934a15762cd694e36fe74f2f2f93eac9b. In order to apply IBRS mitigation for Retbleed, PBRSB mitigations must be reverted and the reapplied, so the backports can look sane. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tracing/histogram: Update document for KEYS_MAX sizeZheng Yejian2022-11-101-1/+1
| | | | | | | | | | | | | | commit a635beeacc6d56d2b71c39e6c0103f85b53d108e upstream. After commit 4f36c2d85ced ("tracing: Increase tracing map KEYS_MAX size"), 'keys' supports up to three fields. Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20221017103806.2479139-1-zhengyejian1@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm64: errata: Remove AES hwcap for COMPAT tasksJames Morse2022-11-031-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | commit 44b3834b2eed595af07021b1c64e6f9bc396398b upstream. Cortex-A57 and Cortex-A72 have an erratum where an interrupt that occurs between a pair of AES instructions in aarch32 mode may corrupt the ELR. The task will subsequently produce the wrong AES result. The AES instructions are part of the cryptographic extensions, which are optional. User-space software will detect the support for these instructions from the hwcaps. If the platform doesn't support these instructions a software implementation should be used. Remove the hwcap bits on affected parts to indicate user-space should not use the AES instructions. Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: James Morse <james.morse@arm.com> Link: https://lore.kernel.org/r/20220714161523.279570-3-james.morse@arm.com Signed-off-by: Will Deacon <will@kernel.org> [florian: resolved conflicts in arch/arm64/tools/cpucaps and cpu_errata.c] Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* iio: ABI: Fix wrong format of differential capacitance channel ABI.Jonathan Cameron2022-10-261-1/+1
| | | | | | | | | | | | [ Upstream commit 1efc41035f1841acf0af2bab153158e27ce94f10 ] in_ only occurs once in these attributes. Fixes: 0baf29d658c7 ("staging:iio:documentation Add abi docs for capacitance adcs.") Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20220626122938.582107-3-jic23@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
* ARM: dts: fix Moxa SDIO 'compatible', remove 'sdhci' misnomerSergei Antonov2022-10-261-2/+2
| | | | | | | | | | | | | | | | | | | | | [ Upstream commit 02181e68275d28cab3c3f755852770367f1bc229 ] Driver moxart-mmc.c has .compatible = "moxa,moxart-mmc". But moxart .dts/.dtsi and the documentation file moxa,moxart-dma.txt contain compatible = "moxa,moxart-sdhci". Change moxart .dts/.dtsi files and moxa,moxart-dma.txt to match the driver. Replace 'sdhci' with 'mmc' in names too, since SDHCI is a different controller from FTSDC010. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sergei Antonov <saproj@gmail.com> Cc: Jonas Jensen <jonas.jensen@gmail.com> Link: https://lore.kernel.org/r/20220907175341.1477383-1-saproj@gmail.com' Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* docs: update mediator information in CoC docsShuah Khan2022-10-261-1/+1
| | | | | | | | | | | | commit 8bfdfa0d6b929ede7b6189e0e546ceb6a124d05d upstream. Update mediator information in the CoC interpretation document. Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Link: https://lore.kernel.org/r/20220901212319.56644-1-skhan@linuxfoundation.org Cc: stable@vger.kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Input: iforce - add support for Boeder Force Feedback WheelGreg Tulli2022-09-201-0/+1
| | | | | | | | | | | | [ Upstream commit 9c9c71168f7979f3798b61c65b4530fbfbcf19d1 ] Add a new iforce_device entry to support the Boeder Force Feedback Wheel device. Signed-off-by: Greg Tulli <greg.iforce@gmail.com> Link: https://lore.kernel.org/r/3256420-c8ac-31b-8499-3c488a9880fd@gmail.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* x86/bugs: Add "unknown" reporting for MMIO Stale DataPawan Gupta2022-09-051-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7df548840c496b0141fb2404b889c346380c2b22 upstream. Older Intel CPUs that are not in the affected processor list for MMIO Stale Data vulnerabilities currently report "Not affected" in sysfs, which may not be correct. Vulnerability status for these older CPUs is unknown. Add known-not-affected CPUs to the whitelist. Report "unknown" mitigation status for CPUs that are not in blacklist, whitelist and also don't enumerate MSR ARCH_CAPABILITIES bits that reflect hardware immunity to MMIO Stale Data vulnerabilities. Mitigation is not deployed when the status is unknown. [ bp: Massage, fixup. ] Fixes: 8d50cdf8b834 ("x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data") Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Suggested-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/a932c154772f2121794a5f2eded1a11013114711.1657846269.git.pawan.kumar.gupta@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* locking/atomic: Make test_and_*_bit() ordered on failureHector Martin2022-08-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 415d832497098030241605c52ea83d4e2cfa7879 upstream. These operations are documented as always ordered in include/asm-generic/bitops/instrumented-atomic.h, and producer-consumer type use cases where one side needs to ensure a flag is left pending after some shared data was updated rely on this ordering, even in the failure case. This is the case with the workqueue code, which currently suffers from a reproducible ordering violation on Apple M1 platforms (which are notoriously out-of-order) that ends up causing the TTY layer to fail to deliver data to userspace properly under the right conditions. This change fixes that bug. Change the documentation to restrict the "no order on failure" story to the _lock() variant (for which it makes sense), and remove the early-exit from the generic implementation, which is what causes the missing barrier semantics in that case. Without this, the remaining atomic op is fully ordered (including on ARM64 LSE, as of recent versions of the architecture spec). Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Fixes: e986a0d6cb36 ("locking/atomics, asm-generic/bitops/atomic.h: Rewrite using atomic_*() APIs") Fixes: 61e02392d3c7 ("locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()") Signed-off-by: Hector Martin <marcan@marcan.st> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation: Add RSB VM Exit protectionsDaniel Sneddon2022-08-111-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2b1299322016731d56807aa49254a5ea3080b6b3 upstream. tl;dr: The Enhanced IBRS mitigation for Spectre v2 does not work as documented for RET instructions after VM exits. Mitigate it with a new one-entry RSB stuffing mechanism and a new LFENCE. == Background == Indirect Branch Restricted Speculation (IBRS) was designed to help mitigate Branch Target Injection and Speculative Store Bypass, i.e. Spectre, attacks. IBRS prevents software run in less privileged modes from affecting branch prediction in more privileged modes. IBRS requires the MSR to be written on every privilege level change. To overcome some of the performance issues of IBRS, Enhanced IBRS was introduced. eIBRS is an "always on" IBRS, in other words, just turn it on once instead of writing the MSR on every privilege level change. When eIBRS is enabled, more privileged modes should be protected from less privileged modes, including protecting VMMs from guests. == Problem == Here's a simplification of how guests are run on Linux' KVM: void run_kvm_guest(void) { // Prepare to run guest VMRESUME(); // Clean up after guest runs } The execution flow for that would look something like this to the processor: 1. Host-side: call run_kvm_guest() 2. Host-side: VMRESUME 3. Guest runs, does "CALL guest_function" 4. VM exit, host runs again 5. Host might make some "cleanup" function calls 6. Host-side: RET from run_kvm_guest() Now, when back on the host, there are a couple of possible scenarios of post-guest activity the host needs to do before executing host code: * on pre-eIBRS hardware (legacy IBRS, or nothing at all), the RSB is not touched and Linux has to do a 32-entry stuffing. * on eIBRS hardware, VM exit with IBRS enabled, or restoring the host IBRS=1 shortly after VM exit, has a documented side effect of flushing the RSB except in this PBRSB situation where the software needs to stuff the last RSB entry "by hand". IOW, with eIBRS supported, host RET instructions should no longer be influenced by guest behavior after the host retires a single CALL instruction. However, if the RET instructions are "unbalanced" with CALLs after a VM exit as is the RET in #6, it might speculatively use the address for the instruction after the CALL in #3 as an RSB prediction. This is a problem since the (untrusted) guest controls this address. Balanced CALL/RET instruction pairs such as in step #5 are not affected. == Solution == The PBRSB issue affects a wide variety of Intel processors which support eIBRS. But not all of them need mitigation. Today, X86_FEATURE_RETPOLINE triggers an RSB filling sequence that mitigates PBRSB. Systems setting RETPOLINE need no further mitigation - i.e., eIBRS systems which enable retpoline explicitly. However, such systems (X86_FEATURE_IBRS_ENHANCED) do not set RETPOLINE and most of them need a new mitigation. Therefore, introduce a new feature flag X86_FEATURE_RSB_VMEXIT_LITE which triggers a lighter-weight PBRSB mitigation versus RSB Filling at vmexit. The lighter-weight mitigation performs a CALL instruction which is immediately followed by a speculative execution barrier (INT3). This steers speculative execution to the barrier -- just like a retpoline -- which ensures that speculation can never reach an unbalanced RET. Then, ensure this CALL is retired before continuing execution with an LFENCE. In other words, the window of exposure is opened at VM exit where RET behavior is troublesome. While the window is open, force RSB predictions sampling for RET targets to a dead end at the INT3. Close the window with the LFENCE. There is a subset of eIBRS systems which are not vulnerable to PBRSB. Add these systems to the cpu_vuln_whitelist[] as NO_EIBRS_PBRSB. Future systems that aren't vulnerable will set ARCH_CAP_PBRSB_NO. [ bp: Massage, incorporate review comments from Andy Cooper. ] [ Pawan: Update commit message to replace RSB_VMEXIT with RETPOLINE ] Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.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: Borislav Petkov <bp@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Documentation: fix sctp_wmem in ip-sysctl.rstXin Long2022-08-111-1/+8
| | | | | | | | | | | | | | | | | | [ Upstream commit aa709da0e032cee7c202047ecd75f437bb0126ed ] Since commit 1033990ac5b2 ("sctp: implement memory accounting on tx path"), SCTP has supported memory accounting on tx path where 'sctp_wmem' is used by sk_wmem_schedule(). So we should fix the description for this option in ip-sysctl.rst accordingly. v1->v2: - Improve the description as Marcelo suggested. Fixes: 1033990ac5b2 ("sctp: implement memory accounting on tx path") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ipv4: Fix data-races around sysctl_ip_dynaddr.Kuniyuki Iwashima2022-07-211-1/+1
| | | | | | | | | | | | [ Upstream commit e49e4aff7ec19b2d0d0957ee30e93dade57dab9e ] While reading sysctl_ip_dynaddr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* cipso: Fix data-races around sysctl.Kuniyuki Iwashima2022-07-211-1/+1
| | | | | | | | | | | | | [ Upstream commit dd44f04b9214adb68ef5684ae87a81ba03632250 ] While reading cipso sysctl variables, they can be changed concurrently. So, we need to add READ_ONCE() to avoid data-races. Fixes: 446fda4f2682 ("[NetLabel]: CIPSOv4 engine") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
* iio: adc: vf610: fix conversion mode sysfs node nameBaruch Siach2022-07-021-1/+1
| | | | | | | | | | | | | | [ Upstream commit f1a633b15cd5371a2a83f02c513984e51132dd68 ] The documentation missed the "in_" prefix for this IIO_SHARED_BY_DIR entry. Fixes: bf04c1a367e3 ("iio: adc: vf610: implement configurable conversion modes") Signed-off-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Haibo Chen <haibo.chen@nxp.com> Link: https://lore.kernel.org/r/560dc93fafe5ef7e9a409885fd20b6beac3973d8.1653900626.git.baruch@tkos.co.il Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Revert "hwmon: Make chip parameter for with_info API mandatory"Greg Kroah-Hartman2022-06-251-1/+1
| | | | | | | | | | | | This reverts commit 1ec0bc72f5dab3ab367ae5230cf6f212d805a225 which is commit ddaefa209c4ac791c1262e97c9b2d0440c8ef1d5 upstream. It should not have been applied to the stable trees. Link: https://lore.kernel.org/r/20220622154454.GA1864037@roeck-us.net Reported-by: Julian Haller <julian.haller@philips.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random: fix sysctl documentation nitsJason A. Donenfeld2022-06-251-4/+4
| | | | | | | | | | commit 069c4ea6871c18bd368f27756e0f91ffb524a788 upstream. A semicolon was missing, and the almost-alphabetical-but-not ordering was confusing, so regroup these by category instead. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random: treat bootloader trust toggle the same way as cpu trust toggleJason A. Donenfeld2022-06-251-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | commit d97c68d178fbf8aaaf21b69b446f2dfb13909316 upstream. If CONFIG_RANDOM_TRUST_CPU is set, the RNG initializes using RDRAND. But, the user can disable (or enable) this behavior by setting `random.trust_cpu=0/1` on the kernel command line. This allows system builders to do reasonable things while avoiding howls from tinfoil hatters. (Or vice versa.) CONFIG_RANDOM_TRUST_BOOTLOADER is basically the same thing, but regards the seed passed via EFI or device tree, which might come from RDRAND or a TPM or somewhere else. In order to allow distros to more easily enable this while avoiding those same howls (or vice versa), this commit adds the corresponding `random.trust_bootloader=0/1` toggle. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Graham Christensen <graham@grahamc.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Link: https://github.com/NixOS/nixpkgs/pull/165355 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random: remove ifdef'd out interrupt benchJason A. Donenfeld2022-06-251-9/+0
| | | | | | | | | | | | | | | commit 95e6060c20a7f5db60163274c5222a725ac118f9 upstream. With tools like kbench9000 giving more finegrained responses, and this basically never having been used ever since it was initially added, let's just get rid of this. There *is* still work to be done on the interrupt handler, but this really isn't the way it's being developed. Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random: always wake up entropy writers after extractionJason A. Donenfeld2022-06-251-2/+42
| | | | | | | | | | | | | | | | | commit 489c7fc44b5740d377e8cfdbf0851036e493af00 upstream. Now that POOL_BITS == POOL_MIN_BITS, we must unconditionally wake up entropy writers after every extraction. Therefore there's no point of write_wakeup_threshold, so we can move it to the dustbin of unused compatibility sysctls. While we're at it, we can fix a small comparison where we were waking up after <= min rather than < min. Cc: Theodore Ts'o <tytso@mit.edu> Suggested-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale DataPawan Gupta2022-06-161-0/+1
| | | | | | | | | | | | | | commit 8d50cdf8b8341770bc6367bce40c0c1bb0e1d5b3 upstream Add the sysfs reporting file for Processor MMIO Stale Data vulnerability. It exposes the vulnerability and mitigation state similar to the existing files for the other hardware vulnerabilities. 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> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/speculation/mmio: Add mitigation for Processor MMIO Stale DataPawan Gupta2022-06-161-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8cb861e9e3c9a55099ad3d08e1a3b653d29c33ca upstream Processor MMIO Stale Data is a class of vulnerabilities that may expose data after an MMIO operation. For details please refer to Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst. These vulnerabilities are broadly categorized as: Device Register Partial Write (DRPW): Some endpoint MMIO registers incorrectly handle writes that are smaller than the register size. Instead of aborting the write or only copying the correct subset of bytes (for example, 2 bytes for a 2-byte write), more bytes than specified by the write transaction may be written to the register. On some processors, this may expose stale data from the fill buffers of the core that created the write transaction. Shared Buffers Data Sampling (SBDS): After propagators may have moved data around the uncore and copied stale data into client core fill buffers, processors affected by MFBDS can leak data from the fill buffer. Shared Buffers Data Read (SBDR): It is similar to Shared Buffer Data Sampling (SBDS) except that the data is directly read into the architectural software-visible state. An attacker can use these vulnerabilities to extract data from CPU fill buffers using MDS and TAA methods. Mitigate it by clearing the CPU fill buffers using the VERW instruction before returning to a user or a guest. On CPUs not affected by MDS and TAA, user application cannot sample data from CPU fill buffers using MDS or TAA. A guest with MMIO access can still use DRPW or SBDR to extract data architecturally. Mitigate it with VERW instruction to clear fill buffers before VMENTER for MMIO capable guests. Add a kernel parameter mmio_stale_data={off|full|full,nosmt} to control the mitigation. 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> [cascardo: arch/x86/kvm/vmx.c has been moved] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Documentation: Add documentation for Processor MMIO Stale DataPawan Gupta2022-06-162-0/+247
| | | | | | | | | | | | commit 4419470191386456e0b8ed4eb06a70b0021798a6 upstream Add the admin guide for Processor MMIO stale data vulnerabilities. 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> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ata: libata-transport: fix {dma|pio|xfer}_mode sysfs filesSergey Shtylyov2022-06-141-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 72aad489f992871e908ff6d9055b26c6366fb864 upstream. The {dma|pio}_mode sysfs files are incorrectly documented as having a list of the supported DMA/PIO transfer modes, while the corresponding fields of the *struct* ata_device hold the transfer mode IDs, not masks. To match these docs, the {dma|pio}_mode (and even xfer_mode!) sysfs files are handled by the ata_bitfield_name_match() macro which leads to reading such kind of nonsense from them: $ cat /sys/class/ata_device/dev3.0/pio_mode XFER_UDMA_7, XFER_UDMA_6, XFER_UDMA_5, XFER_UDMA_4, XFER_MW_DMA_4, XFER_PIO_6, XFER_PIO_5, XFER_PIO_4, XFER_PIO_3, XFER_PIO_2, XFER_PIO_1, XFER_PIO_0 Using the correct ata_bitfield_name_search() macro fixes that: $ cat /sys/class/ata_device/dev3.0/pio_mode XFER_PIO_4 While fixing the file documentation, somewhat reword the {dma|pio}_mode file doc and add a note about being mostly useful for PATA devices to the xfer_mode file doc... Fixes: d9027470b886 ("[libata] Add ATA transport class") Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dt-bindings: gpio: altera: correct interrupt-cellsDinh Nguyen2022-06-141-2/+3
| | | | | | | | | | | commit 3a21c3ac93aff7b4522b152399df8f6a041df56d upstream. update documentation to correctly state the interrupt-cells to be 2. Cc: stable@vger.kernel.org Fixes: 4fd9bbc6e071 ("drivers/gpio: Altera soft IP GPIO driver devicetree binding") Signed-off-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* docs/conf.py: Cope with removal of language=None in Sphinx 5.0.0Akira Yokosawa2022-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 627f01eab93d8671d4e4afee9b148f9998d20e7c upstream. One of the changes in Sphinx 5.0.0 [1] says [sic]: 5.0.0 final - #10474: language does not accept None as it value. The default value of language becomes to 'en' now. [1]: https://www.sphinx-doc.org/en/master/changes.html#release-5-0-0-released-may-30-2022 It results in a new warning from Sphinx 5.0.0 [sic]: WARNING: Invalid configuration value found: 'language = None'. Update your configuration to a valid langauge code. Falling back to 'en' (English). Silence the warning by using 'en'. It works with all the Sphinx versions required for building kernel documentation (1.7.9 or later). Signed-off-by: Akira Yokosawa <akiyks@gmail.com> Link: https://lore.kernel.org/r/bd0c2ddc-2401-03cb-4526-79ca664e1cbe@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* hwmon: Make chip parameter for with_info API mandatoryGuenter Roeck2022-06-141-1/+1
| | | | | | | | | | | | | [ Upstream commit ddaefa209c4ac791c1262e97c9b2d0440c8ef1d5 ] Various attempts were made recently to "convert" the old hwmon_device_register() API to devm_hwmon_device_register_with_info() by just changing the function name without actually converting the driver. Prevent this from happening by making the 'chip' parameter of devm_hwmon_device_register_with_info() mandatory. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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