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2020-12-02x86/resctrl: Add necessary kernfs_put() calls to prevent refcount leakXiaochen Shen1-7/+25
commit 758999246965eeb8b253d47e72f7bfe508804b16 upstream. On resource group creation via a mkdir an extra kernfs_node reference is obtained by kernfs_get() to ensure that the rdtgroup structure remains accessible for the rdtgroup_kn_unlock() calls where it is removed on deletion. Currently the extra kernfs_node reference count is only dropped by kernfs_put() in rdtgroup_kn_unlock() while the rdtgroup structure is removed in a few other locations that lack the matching reference drop. In call paths of rmdir and umount, when a control group is removed, kernfs_remove() is called to remove the whole kernfs nodes tree of the control group (including the kernfs nodes trees of all child monitoring groups), and then rdtgroup structure is freed by kfree(). The rdtgroup structures of all child monitoring groups under the control group are freed by kfree() in free_all_child_rdtgrp(). Before calling kfree() to free the rdtgroup structures, the kernfs node of the control group itself as well as the kernfs nodes of all child monitoring groups still take the extra references which will never be dropped to 0 and the kernfs nodes will never be freed. It leads to reference count leak and kernfs_node_cache memory leak. For example, reference count leak is observed in these two cases: (1) mount -t resctrl resctrl /sys/fs/resctrl mkdir /sys/fs/resctrl/c1 mkdir /sys/fs/resctrl/c1/mon_groups/m1 umount /sys/fs/resctrl (2) mkdir /sys/fs/resctrl/c1 mkdir /sys/fs/resctrl/c1/mon_groups/m1 rmdir /sys/fs/resctrl/c1 The same reference count leak issue also exists in the error exit paths of mkdir in mkdir_rdt_prepare() and rdtgroup_mkdir_ctrl_mon(). Fix this issue by following changes to make sure the extra kernfs_node reference on rdtgroup is dropped before freeing the rdtgroup structure. (1) Introduce rdtgroup removal helper rdtgroup_remove() to wrap up kernfs_put() and kfree(). (2) Call rdtgroup_remove() in rdtgroup removal path where the rdtgroup structure is about to be freed by kfree(). (3) Call rdtgroup_remove() or kernfs_put() as appropriate in the error exit paths of mkdir where an extra reference is taken by kernfs_get(). Backporting notes: Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt files to a separate directory"), the file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to arch/x86/kernel/cpu/resctrl/rdtgroup.c. Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c in older stable trees. Fixes: f3cbeacaa06e ("x86/intel_rdt/cqm: Add rmdir support") Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files") Fixes: 60cf5e101fd4 ("x86/intel_rdt: Add mkdir to resctrl file system") Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1604085088-31707-1-git-send-email-xiaochen.shen@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-02x86/resctrl: Remove superfluous kernfs_get() calls to prevent refcount leakXiaochen Shen1-33/+2
commit fd8d9db3559a29fd737bcdb7c4fcbe1940caae34 upstream. Willem reported growing of kernfs_node_cache entries in slabtop when repeatedly creating and removing resctrl subdirectories as well as when repeatedly mounting and unmounting the resctrl filesystem. On resource group (control as well as monitoring) creation via a mkdir an extra kernfs_node reference is obtained to ensure that the rdtgroup structure remains accessible for the rdtgroup_kn_unlock() calls where it is removed on deletion. The kernfs_node reference count is dropped by kernfs_put() in rdtgroup_kn_unlock(). With the above explaining the need for one kernfs_get()/kernfs_put() pair in resctrl there are more places where a kernfs_node reference is obtained without a corresponding release. The excessive amount of reference count on kernfs nodes will never be dropped to 0 and the kernfs nodes will never be freed in the call paths of rmdir and umount. It leads to reference count leak and kernfs_node_cache memory leak. Remove the superfluous kernfs_get() calls and expand the existing comments surrounding the remaining kernfs_get()/kernfs_put() pair that remains in use. Superfluous kernfs_get() calls are removed from two areas: (1) In call paths of mount and mkdir, when kernfs nodes for "info", "mon_groups" and "mon_data" directories and sub-directories are created, the reference count of newly created kernfs node is set to 1. But after kernfs_create_dir() returns, superfluous kernfs_get() are called to take an additional reference. (2) kernfs_get() calls in rmdir call paths. Backporting notes: Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt files to a separate directory"), the file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to arch/x86/kernel/cpu/resctrl/rdtgroup.c. Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c for older stable trees. Fixes: 17eafd076291 ("x86/intel_rdt: Split resource group removal in two") Fixes: 4af4a88e0c92 ("x86/intel_rdt/cqm: Add mount,umount support") Fixes: f3cbeacaa06e ("x86/intel_rdt/cqm: Add rmdir support") Fixes: d89b7379015f ("x86/intel_rdt/cqm: Add mon_data") Fixes: c7d9aac61311 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring") Fixes: 5dc1d5c6bac2 ("x86/intel_rdt: Simplify info and base file lists") Fixes: 60cf5e101fd4 ("x86/intel_rdt: Add mkdir to resctrl file system") Fixes: 4e978d06dedb ("x86/intel_rdt: Add "info" files to resctrl file system") Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Willem de Bruijn <willemb@google.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1604085053-31639-1-git-send-email-xiaochen.shen@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-02x86/speculation: Fix prctl() when spectre_v2_user={seccomp,prctl},ibpbAnand K Mistry1-2/+2
commit 33fc379df76b4991e5ae312f07bcd6820811971e upstream. When spectre_v2_user={seccomp,prctl},ibpb is specified on the command line, IBPB is force-enabled and STIPB is conditionally-enabled (or not available). However, since 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.") the spectre_v2_user_ibpb variable is set to SPECTRE_V2_USER_{PRCTL,SECCOMP} instead of SPECTRE_V2_USER_STRICT, which is the actual behaviour. Because the issuing of IBPB relies on the switch_mm_*_ibpb static branches, the mitigations behave as expected. Since 1978b3a53a74 ("x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP") this discrepency caused the misreporting of IB speculation via prctl(). On CPUs with STIBP always-on and spectre_v2_user=seccomp,ibpb, prctl(PR_GET_SPECULATION_CTRL) would return PR_SPEC_PRCTL | PR_SPEC_ENABLE instead of PR_SPEC_DISABLE since both IBPB and STIPB are always on. It also allowed prctl(PR_SET_SPECULATION_CTRL) to set the IB speculation mode, even though the flag is ignored. Similarly, for CPUs without SMT, prctl(PR_GET_SPECULATION_CTRL) should also return PR_SPEC_DISABLE since IBPB is always on and STIBP is not available. [ bp: Massage commit message. ] Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.") Fixes: 1978b3a53a74 ("x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP") Signed-off-by: Anand K Mistry <amistry@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201110123349.1.Id0cbf996d2151f4c143c90f9028651a5b49a5908@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-02ARM: dts: dra76x: m_can: fix order of clocksMarc Kleine-Budde1-2/+2
[ Upstream commit 05d5de6ba7dbe490dd413b5ca11d0875bd2bc006 ] According to the bosch,m_can.yaml bindings the first clock shall be the "hclk", while the second clock "cclk". This patch fixes the order accordingly. Fixes: 0adbe832f21a ("ARM: dts: dra76x: Add MCAN node") Cc: Faiz Abbas <faiz_abbas@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: linux-omap@vger.kernel.org Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02xtensa: uaccess: Add missing __user to strncpy_from_user() prototypeLaurent Pinchart1-1/+1
[ Upstream commit dc293f2106903ab9c24e9cea18c276e32c394c33 ] When adding __user annotations in commit 2adf5352a34a, the strncpy_from_user() function declaration for the CONFIG_GENERIC_STRNCPY_FROM_USER case was missed. Fix it. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Message-Id: <20200831210937.17938-1-laurent.pinchart@ideasonboard.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02perf/x86: fix sysfs type mismatchesSami Tolvanen4-24/+12
[ Upstream commit ebd19fc372e3e78bf165f230e7c084e304441c08 ] This change switches rapl to use PMU_FORMAT_ATTR, and fixes two other macros to use device_attribute instead of kobj_attribute to avoid callback type mismatches that trip indirect call checking with Clang's Control-Flow Integrity (CFI). Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20201113183126.1239404-1-samitolvanen@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02x86/xen: don't unbind uninitialized lock_kicker_irqBrian Masney1-1/+11
[ Upstream commit 65cae18882f943215d0505ddc7e70495877308e6 ] When booting a hyperthreaded system with the kernel parameter 'mitigations=auto,nosmt', the following warning occurs: WARNING: CPU: 0 PID: 1 at drivers/xen/events/events_base.c:1112 unbind_from_irqhandler+0x4e/0x60 ... Hardware name: Xen HVM domU, BIOS 4.2.amazon 08/24/2006 ... Call Trace: xen_uninit_lock_cpu+0x28/0x62 xen_hvm_cpu_die+0x21/0x30 takedown_cpu+0x9c/0xe0 ? trace_suspend_resume+0x60/0x60 cpuhp_invoke_callback+0x9a/0x530 _cpu_up+0x11a/0x130 cpu_up+0x7e/0xc0 bringup_nonboot_cpus+0x48/0x50 smp_init+0x26/0x79 kernel_init_freeable+0xea/0x229 ? rest_init+0xaa/0xaa kernel_init+0xa/0x106 ret_from_fork+0x35/0x40 The secondary CPUs are not activated with the nosmt mitigations and only the primary thread on each CPU core is used. In this situation, xen_hvm_smp_prepare_cpus(), and more importantly xen_init_lock_cpu(), is not called, so the lock_kicker_irq is not initialized for the secondary CPUs. Let's fix this by exiting early in xen_uninit_lock_cpu() if the irq is not set to avoid the warning from above for each secondary CPU. Signed-off-by: Brian Masney <bmasney@redhat.com> Link: https://lore.kernel.org/r/20201107011119.631442-1-bmasney@redhat.com Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect()Will Deacon1-13/+14
commit ff1712f953e27f0b0718762ec17d0adb15c9fd0b upstream. With hardware dirty bit management, calling pte_wrprotect() on a writable, dirty PTE will lose the dirty state and return a read-only, clean entry. Move the logic from ptep_set_wrprotect() into pte_wrprotect() to ensure that the dirty bit is preserved for writable entries, as this is required for soft-dirty bit management if we enable it in the future. Cc: <stable@vger.kernel.org> Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20201120143557.6715-3-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-02arm64: pgtable: Fix pte_accessible()Will Deacon1-3/+4
commit 07509e10dcc77627f8b6a57381e878fe269958d3 upstream. pte_accessible() is used by ptep_clear_flush() to figure out whether TLB invalidation is necessary when unmapping pages for reclaim. Although our implementation is correct according to the architecture, returning true only for valid, young ptes in the absence of racing page-table modifications, this is in fact flawed due to lazy invalidation of old ptes in ptep_clear_flush_young() where we elide the expensive DSB instruction for completing the TLB invalidation. Rather than penalise the aging path, adjust pte_accessible() to return true for any valid pte, even if the access flag is cleared. Cc: <stable@vger.kernel.org> Fixes: 76c714be0e5e ("arm64: pgtable: implement pte_accessible()") Reported-by: Yu Zhao <yuzhao@google.com> Acked-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20201120143557.6715-2-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-02KVM: x86: Fix split-irqchip vs interrupt injection window requestPaolo Bonzini3-9/+12
commit 71cc849b7093bb83af966c0e60cb11b7f35cd746 upstream. kvm_cpu_accept_dm_intr and kvm_vcpu_ready_for_interrupt_injection are a hodge-podge of conditions, hacked together to get something that more or less works. But what is actually needed is much simpler; in both cases the fundamental question is, do we have a place to stash an interrupt if userspace does KVM_INTERRUPT? In userspace irqchip mode, that is !vcpu->arch.interrupt.injected. Currently kvm_event_needs_reinjection(vcpu) covers it, but it is unnecessarily restrictive. In split irqchip mode it's a bit more complicated, we need to check kvm_apic_accept_pic_intr(vcpu) (the IRQ window exit is basically an INTACK cycle and thus requires ExtINTs not to be masked) as well as !pending_userspace_extint(vcpu). However, there is no need to check kvm_event_needs_reinjection(vcpu), since split irqchip keeps pending ExtINT state separate from event injection state, and checking kvm_cpu_has_interrupt(vcpu) is wrong too since ExtINT has higher priority than APIC interrupts. In fact the latter fixes a bug: when userspace requests an IRQ window vmexit, an interrupt in the local APIC can cause kvm_cpu_has_interrupt() to be true and thus kvm_vcpu_ready_for_interrupt_injection() to return false. When this happens, vcpu_run does not exit to userspace but the interrupt window vmexits keep occurring. The VM loops without any hope of making progress. Once we try to fix these with something like return kvm_arch_interrupt_allowed(vcpu) && - !kvm_cpu_has_interrupt(vcpu) && - !kvm_event_needs_reinjection(vcpu) && - kvm_cpu_accept_dm_intr(vcpu); + (!lapic_in_kernel(vcpu) + ? !vcpu->arch.interrupt.injected + : (kvm_apic_accept_pic_intr(vcpu) + && !pending_userspace_extint(v))); we realize two things. First, thanks to the previous patch the complex conditional can reuse !kvm_cpu_has_extint(vcpu). Second, the interrupt window request in vcpu_enter_guest() bool req_int_win = dm_request_for_irq_injection(vcpu) && kvm_cpu_accept_dm_intr(vcpu); should be kept in sync with kvm_vcpu_ready_for_interrupt_injection(): it is unnecessary to ask the processor for an interrupt window if we would not be able to return to userspace. Therefore, kvm_cpu_accept_dm_intr(vcpu) is basically !kvm_cpu_has_extint(vcpu) ANDed with the existing check for masked ExtINT. It all makes sense: - we can accept an interrupt from userspace if there is a place to stash it (and, for irqchip split, ExtINTs are not masked). Interrupts from userspace _can_ be accepted even if right now EFLAGS.IF=0. - in order to tell userspace we will inject its interrupt ("IRQ window open" i.e. kvm_vcpu_ready_for_interrupt_injection), both KVM and the vCPU need to be ready to accept the interrupt. ... and this is what the patch implements. Reported-by: David Woodhouse <dwmw@amazon.co.uk> Analyzed-by: David Woodhouse <dwmw@amazon.co.uk> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-02KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extintPaolo Bonzini2-51/+34
commit 72c3bcdcda494cbd600712a32e67702cdee60c07 upstream. Centralize handling of interrupts from the userspace APIC in kvm_cpu_has_extint and kvm_cpu_get_extint, since userspace APIC interrupts are handled more or less the same as ExtINTs are with split irqchip. This removes duplicated code from kvm_cpu_has_injectable_intr and kvm_cpu_has_interrupt, and makes the code more similar between kvm_cpu_has_{extint,interrupt} on one side and kvm_cpu_get_{extint,interrupt} on the other. Cc: stable@vger.kernel.org Reviewed-by: Filippo Sironi <sironi@amazon.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24x86/microcode/intel: Check patch signature before saving microcode for early ↵Chen Yu1-53/+10
loading commit 1a371e67dc77125736cc56d3a0893f06b75855b6 upstream. Currently, scan_microcode() leverages microcode_matches() to check if the microcode matches the CPU by comparing the family and model. However, the processor stepping and flags of the microcode signature should also be considered when saving a microcode patch for early update. Use find_matching_signature() in scan_microcode() and get rid of the now-unused microcode_matches() which is a good cleanup in itself. Complete the verification of the patch being saved for early loading in save_microcode_patch() directly. This needs to be done there too because save_mc_for_early() will call save_microcode_patch() too. The second reason why this needs to be done is because the loader still tries to support, at least hypothetically, mixed-steppings systems and thus adds all patches to the cache that belong to the same CPU model albeit with different steppings. For example: microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6 microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23 microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27 microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23 microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27 microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23 The patch which is being saved for early loading, however, can only be the one which fits the CPU this runs on so do the signature verification before saving. [ bp: Do signature verification in save_microcode_patch() and rewrite commit message. ] Fixes: ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU") Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=208535 Link: https://lkml.kernel.org/r/20201113015923.13960-1-yu.c.chen@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24s390/cpum_sf.c: fix file permission for cpum_sfb_sizeThomas Richter1-1/+1
commit 78d732e1f326f74f240d416af9484928303d9951 upstream. This file is installed by the s390 CPU Measurement sampling facility device driver to export supported minimum and maximum sample buffer sizes. This file is read by lscpumf tool to display the details of the device driver capabilities. The lscpumf tool might be invoked by a non-root user. In this case it does not print anything because the file contents can not be read. Fix this by allowing read access for all users. Reading the file contents is ok, changing the file contents is left to the root user only. For further reference and details see: [1] https://github.com/ibm-s390-tools/s390-tools/issues/97 Fixes: 69f239ed335a ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur") Cc: <stable@vger.kernel.org> # 3.14 Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24xtensa: disable preemption around cache alias management callsMax Filippov1-0/+14
commit 3a860d165eb5f4d7cf0bf81ef6a5b5c5e1754422 upstream. Although cache alias management calls set up and tear down TLB entries and fast_second_level_miss is able to restore TLB entry should it be evicted they absolutely cannot preempt each other because they use the same TLBTEMP area for different purposes. Disable preemption around all cache alias management calls to enforce that. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24efi/x86: Free efi_pgd with free_pages()Arvind Sankar1-11/+13
[ Upstream commit c2fe61d8be491ff8188edaf22e838f819999146b ] Commit d9e9a6418065 ("x86/mm/pti: Allocate a separate user PGD") changed the PGD allocation to allocate PGD_ALLOCATION_ORDER pages, so in the error path it should be freed using free_pages() rather than free_page(). Commit 06ace26f4e6f ("x86/efi: Free efi_pgd with free_pages()") fixed one instance of this, but missed another. Move the freeing out-of-line to avoid code duplication and fix this bug. Fixes: d9e9a6418065 ("x86/mm/pti: Allocate a separate user PGD") Link: https://lore.kernel.org/r/20201110163919.1134431-1-nivedita@alum.mit.edu Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24MIPS: Alchemy: Fix memleak in alchemy_clk_setup_cpuZhang Qilong1-1/+8
[ Upstream commit ac3b57adf87ad9bac7e33ca26bbbb13fae1ed62b ] If the clk_register fails, we should free h before function returns to prevent memleak. Fixes: 474402291a0ad ("MIPS: Alchemy: clock framework integration of onchip clocks") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24ARM: dts: imx50-evk: Fix the chip select 1 IOMUXFabio Estevam1-1/+1
[ Upstream commit 33d0d843872c5ddbe28457a92fc6f2487315fb9f ] The SPI chip selects are represented as: cs-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>, <&gpio4 13 GPIO_ACTIVE_LOW>; , which means that they are used in GPIO function instead of native SPI mode. Fix the IOMUX for the chip select 1 to use GPIO4_13 instead of the native CSPI_SSI function. Fixes: c605cbf5e135 ("ARM: dts: imx: add device tree support for Freescale imx50evk board") Signed-off-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24arm: dts: imx6qdl-udoo: fix rgmii phy-mode for ksz9031 phySergey Matyukevich1-1/+1
[ Upstream commit 7dd8f0ba88fce98e2953267a66af74c6f4792a56 ] Commit bcf3440c6dd7 ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY") fixed micrel phy driver adding proper support for phy modes. Adapt imx6q-udoo board phy settings : explicitly set required delay configuration using "rgmii-id". Fixes: cbd54fe0b2bc ("ARM: dts: imx6dl-udoo: Add board support based off imx6q-udoo") Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com> Reviewed-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24arm64: dts: allwinner: h5: OrangePi Prime: Fix ethernet nodeNenad Peric1-1/+1
[ Upstream commit 107954afc5df667da438644aa4982606663f9b17 ] RX and TX delay are provided by ethernet PHY. Reflect that in ethernet node. Fixes: 44a94c7ef989 ("arm64: dts: allwinner: H5: Restore EMAC changes") Signed-off-by: Nenad Peric <nperic@gmail.com> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Acked-by: Jernej Skrabec <jernej.skrabec@siol.net> Link: https://lore.kernel.org/r/20201028115817.68113-1-nperic@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24MIPS: export has_transparent_hugepage() for modulesRandy Dunlap1-0/+1
[ Upstream commit 31b4d8e172f614adc53ddecb4b6b2f6411a49b84 ] MIPS should export its local version of "has_transparent_hugepage" so that loadable modules (dax) can use it. Fixes this build error: ERROR: modpost: "has_transparent_hugepage" [drivers/dax/dax.ko] undefined! Fixes: fd8cfd300019 ("arch: fix has_transparent_hugepage()") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: linux-mips@vger.kernel.org Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: linux-nvdimm@lists.01.org Cc: Hugh Dickins <hughd@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24arm64: dts: allwinner: a64: bananapi-m64: Enable RGMII RX/TX delay on PHYChen-Yu Tsai1-1/+1
[ Upstream commit 1a9a8910b2153cd3c4f3f2f8defcb853ead3b1fd ] The Ethernet PHY on the Bananapi M64 has the RX and TX delays enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins. Fix the phy-mode description to correct reflect this so that the implementation doesn't reconfigure the delays incorrectly. This happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e rx/tx delay config"). Fixes: e7295499903d ("arm64: allwinner: bananapi-m64: Enable dwmac-sun8i") Fixes: 94f442886711 ("arm64: dts: allwinner: A64: Restore EMAC changes") Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com> Acked-by: Jernej Skrabec <jernej.skrabec@siol.net> Link: https://lore.kernel.org/r/20201024162515.30032-10-wens@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24ARM: dts: sun8i: a83t: Enable both RGMII RX/TX delay on Ethernet PHYChen-Yu Tsai2-2/+2
[ Upstream commit 57dbe558457bf4042169bc1f334e3b53a8480a1c ] The Ethernet PHY on the Bananapi M3 and Cubietruck Plus have the RX and TX delays enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins. Fix the phy-mode description to correct reflect this so that the implementation doesn't reconfigure the delays incorrectly. This happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e rx/tx delay config"). Fixes: 039359948a4b ("ARM: dts: sun8i: a83t: Enable Ethernet on two boards") Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Acked-by: Jernej Skrabec <jernej.skrabec@siol.net> Link: https://lore.kernel.org/r/20201024162515.30032-6-wens@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24ARM: dts: sun8i: h3: orangepi-plus2e: Enable RGMII RX/TX delay on Ethernet PHYChen-Yu Tsai1-1/+1
[ Upstream commit e080ab31a0aa126b0a7e4f67f2b01b371b852c88 ] The Ethernet PHY on the Orange Pi Plus 2E has the RX and TX delays enabled on the PHY, using pull-ups on the RXDLY and TXDLY pins. Fix the phy-mode description to correct reflect this so that the implementation doesn't reconfigure the delays incorrectly. This happened with commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e rx/tx delay config"). Fixes: 4904337fe34f ("ARM: dts: sunxi: Restore EMAC changes (boards)") Fixes: 7a78ef92cdc5 ("ARM: sun8i: h3: Enable EMAC with external PHY on Orange Pi Plus 2E") Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Tested-by: Jernej Skrabec <jernej.skrabec@siol.net> Acked-by: Jernej Skrabec <jernej.skrabec@siol.net> Link: https://lore.kernel.org/r/20201024162515.30032-5-wens@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24Revert "arm: sun8i: orangepi-pc-plus: Set EMAC activity LEDs to active high"Chen-Yu Tsai1-5/+0
[ Upstream commit 8d80e2f00a42ef10b54e1b2d9e97314f8fd046c0 ] This reverts commit 75ee680cbd2e4d0156b94f9fec50076361ab12f2. Turns out the activity and link LEDs on the RJ45 port are active low, just like on the Orange Pi PC. Revert the commit that says otherwise. Fixes: 75ee680cbd2e ("arm: sun8i: orangepi-pc-plus: Set EMAC activity LEDs to active high") Fixes: 4904337fe34f ("ARM: dts: sunxi: Restore EMAC changes (boards)") Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Tested-by: Jernej Skrabec <jernej.skrabec@siol.net> Acked-by: Jernej Skrabec <jernej.skrabec@siol.net> Link: https://lore.kernel.org/r/20201024162515.30032-1-wens@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24ARM: dts: sun8i: r40: bananapi-m2-ultra: Fix ethernet nodeJernej Skrabec1-1/+1
[ Upstream commit b3eec3212e66ece33f69be0de98d54e67834e798 ] Ethernet PHY on BananaPi M2 Ultra provides RX and TX delays. Fix ethernet node to reflect that fact. Fixes: c36fd5a48bd2 ("ARM: dts: sun8i: r40: bananapi-m2-ultra: Enable GMAC ethernet controller") Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Link: https://lore.kernel.org/r/20201025081949.783443-1-jernej.skrabec@siol.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24arm64: dts: allwinner: h5: OrangePi PC2: Fix ethernet nodeJernej Skrabec1-1/+1
[ Upstream commit b34bf9f6a623ddb82600a5ed5c644224122395e1 ] RX and TX delay are provided by ethernet PHY. Reflect that in ethernet node. Fixes: 44a94c7ef989 ("arm64: dts: allwinner: H5: Restore EMAC changes") Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Link: https://lore.kernel.org/r/20201023184858.3272918-1-jernej.skrabec@siol.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24arm64: dts: allwinner: a64: Pine64 Plus: Fix ethernet nodeJernej Skrabec1-1/+1
[ Upstream commit 927f42fcc1b4f7d04a2ac5cf02f25612aa8923a4 ] According to board schematic, PHY provides both, RX and TX delays. However, according to "fix" Realtek provided for this board, only TX delay should be provided by PHY. Tests show that both variants work but TX only PHY delay works slightly better. Update ethernet node to reflect the fact that PHY provides TX delay. Fixes: 94f442886711 ("arm64: dts: allwinner: A64: Restore EMAC changes") Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Link: https://lore.kernel.org/r/20201022211301.3548422-1-jernej.skrabec@siol.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24arm64: psci: Avoid printing in cpu_psci_cpu_die()Will Deacon1-4/+1
[ Upstream commit 891deb87585017d526b67b59c15d38755b900fea ] cpu_psci_cpu_die() is called in the context of the dying CPU, which will no longer be online or tracked by RCU. It is therefore not generally safe to call printk() if the PSCI "cpu off" request fails, so remove the pr_crit() invocation. Cc: Qian Cai <cai@redhat.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20201106103602.9849-2-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-22KVM: x86: clflushopt should be treated as a no-op by emulationDavid Edmondson1-1/+7
commit 51b958e5aeb1e18c00332e0b37c5d4e95a3eff84 upstream. The instruction emulator ignores clflush instructions, yet fails to support clflushopt. Treat both similarly. Fixes: 13e457e0eebf ("KVM: x86: Emulator does not decode clflush well") Signed-off-by: David Edmondson <david.edmondson@oracle.com> Message-Id: <20201103120400.240882-1-david.edmondson@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/8xx: Always fault when _PAGE_ACCESSED is not setChristophe Leroy1-6/+2
commit 29daf869cbab69088fe1755d9dd224e99ba78b56 upstream. The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. This adds at least 3 instructions to the TLB miss exception handlers fast path. Following patch will reduce this overhead. Also update the rotation instruction to the correct number of bits to reflect all changes done to _PAGE_ACCESSED over time. Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.") Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU") Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits") Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC") Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/64s: flush L1D after user accessesNicholas Piggin11-59/+194
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>
2020-11-22powerpc/uaccess: Evaluate macro arguments once, before user access is allowedNicholas Piggin1-14/+35
commit d02f6b7dab8228487268298ea1f21081c0b4b3eb upstream. get/put_user() can be called with nontrivial arguments. fs/proc/page.c has a good example: if (put_user(stable_page_flags(ppage), out)) { stable_page_flags() is quite a lot of code, including spin locks in the page allocator. Ensure these arguments are evaluated before user access is allowed. This improves security by reducing code with access to userspace, but it also fixes a PREEMPT bug with KUAP on powerpc/64s: stable_page_flags() is currently called with AMR set to allow writes, it ends up calling spin_unlock(), which can call preempt_schedule. But the task switch code can not be called with AMR set (it relies on interrupts saving the register), so this blows up. It's fine if the code inside allow_user_access() is preemptible, because a timer or IPI will save the AMR, but it's not okay to explicitly cause a reschedule. Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200407041245.600651-1-npiggin@gmail.com Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc: Fix __clear_user() with KUAP enabledAndrew Donnellan3-7/+12
commit 61e3acd8c693a14fc69b824cb5b08d02cb90a6e7 upstream. The KUAP implementation adds calls in clear_user() to enable and disable access to userspace memory. However, it doesn't add these to __clear_user(), which is used in the ptrace regset code. As there's only one direct user of __clear_user() (the regset code), and the time taken to set the AMR for KUAP purposes is going to dominate the cost of a quick access_ok(), there's not much point having a separate path. Rename __clear_user() to __arch_clear_user(), and make __clear_user() just call clear_user(). Reported-by: syzbot+f25ecf4b2982d8c7a640@syzkaller-ppc64.appspotmail.com Reported-by: Daniel Axtens <dja@axtens.net> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> [mpe: Use __arch_clear_user() for the asm version like arm64 & nds32] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191209132221.15328-1-ajd@linux.ibm.com Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc: Implement user_access_begin and friendsChristophe Leroy1-19/+56
commit 5cd623333e7cf4e3a334c70529268b65f2a6c2c7 upstream. Today, when a function like strncpy_from_user() is called, the userspace access protection is de-activated and re-activated for every word read. By implementing user_access_begin and friends, the protection is de-activated at the beginning of the copy and re-activated at the end. Implement user_access_begin(), user_access_end() and unsafe_get_user(), unsafe_put_user() and unsafe_copy_to_user() For the time being, we keep user_access_save() and user_access_restore() as nops. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/36d4fbf9e56a75994aca4ee2214c77b26a5a8d35.1579866752.git.christophe.leroy@c-s.fr Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc: Add a framework for user access trackingChristophe Leroy4-8/+74
Backported from commit de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection"). Here we don't try to add the KUAP framework, we just want the helper functions because we want to put uaccess flush helpers in them. In terms of fixes, we don't need commit 1d8f739b07bd ("powerpc/kuap: Fix set direction in allow/prevent_user_access()") as we don't have real KUAP. Likewise as all our allows are noops and all our prevents are just flushes, we don't need commit 9dc086f1e9ef ("powerpc/futex: Fix incorrect user access blocking") The other 2 fixes we do need. The original description is: This patch implements a framework for Kernel Userspace Access Protection. Then subarches will have the possibility to provide their own implementation by providing setup_kuap() and allow/prevent_user_access(). Some platforms will need to know the area accessed and whether it is accessed from read, write or both. Therefore source, destination and size and handed over to the two functions. mpe: Rename to allow/prevent rather than unlock/lock, and add read/write wrappers. Drop the 32-bit code for now until we have an implementation for it. Add kuap to pt_regs for 64-bit as well as 32-bit. Don't split strings, use pr_crit_ratelimited(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/64s: flush L1D on kernel entryNicholas Piggin10-7/+202
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>
2020-11-22powerpc/64s: move some exception handlers out of lineDaniel Axtens1-2/+8
(backport only) We're about to grow the exception handlers, which will make a bunch of them no longer fit within the space available. We move them out of line. This is a fiddly and error-prone business, so in the interests of reviewability I haven't merged this in with the addition of the entry flush. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18x86/speculation: Allow IBPB to be conditionally enabled on CPUs with ↵Anand K Mistry1-19/+33
always-on STIBP commit 1978b3a53a74e3230cd46932b149c6e62e832e9a upstream. On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON, STIBP is set to on and spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED At the same time, IBPB can be set to conditional. However, this leads to the case where it's impossible to turn on IBPB for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED condition leads to a return before the task flag is set. Similarly, ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to conditional. More generally, the following cases are possible: 1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb 2. STIBP = on && IBPB = conditional for AMD CPUs with X86_FEATURE_AMD_STIBP_ALWAYS_ON The first case functions correctly today, but only because spectre_v2_user_ibpb isn't updated to reflect the IBPB mode. At a high level, this change does one thing. If either STIBP or IBPB is set to conditional, allow the prctl to change the task flag. Also, reflect that capability when querying the state. This isn't perfect since it doesn't take into account if only STIBP or IBPB is unconditionally on. But it allows the conditional feature to work as expected, without affecting the unconditional one. [ bp: Massage commit message and comment; space out statements for better readability. ] Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.") Signed-off-by: Anand K Mistry <amistry@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18ARM: 9019/1: kprobes: Avoid fortify_panic() when copying optprobe templateAndrew Jeffery2-20/+20
[ Upstream commit 9fa2e7af3d53a4b769136eccc32c02e128a4ee51 ] Setting both CONFIG_KPROBES=y and CONFIG_FORTIFY_SOURCE=y on ARM leads to a panic in memcpy() when injecting a kprobe despite the fixes found in commit e46daee53bb5 ("ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE") and commit 0ac569bf6a79 ("ARM: 8834/1: Fix: kprobes: optimized kprobes illegal instruction"). arch/arm/include/asm/kprobes.h effectively declares the target type of the optprobe_template_entry assembly label as a u32 which leads memcpy()'s __builtin_object_size() call to determine that the pointed-to object is of size four. However, the symbol is used as a handle for the optimised probe assembly template that is at least 96 bytes in size. The symbol's use despite its type blows up the memcpy() in ARM's arch_prepare_optimized_kprobe() with a false-positive fortify_panic() when it should instead copy the optimised probe template into place: ``` $ sudo perf probe -a aspeed_g6_pinctrl_probe [ 158.457252] detected buffer overflow in memc