When stopping the CRTC the driver must disable all planes and wait for
the change to take effect at the next vblank. Merely calling
drm_crtc_wait_one_vblank() is not enough, as the function doesn't
include any mechanism to handle the race with vblank interrupts.
Replace the drm_crtc_wait_one_vblank() call with a manual mechanism that
handles the vblank interrupt race.
When implementing support for interlaced modes, the driver switched from
reporting vblank events on the vertical blanking (VBK) interrupt to the
frame end interrupt (FRM). This incorrectly divided the reported refresh
rate by two. Fix it by moving back to the VBK interrupt.
commit 1f8754d4daea5f ("ASoC: rsnd: don't call free_irq() on
Parent SSI") fixed Parent SSI duplicate free_irq().
But on Renesas Sound, not only Parent SSI but also Multi SSI
have same issue.
This patch avoid duplicate free_irq() if it was not pure SSI.
Fixes: 1f8754d4daea5f ("ASoC: rsnd: don't call free_irq() on Parent SSI") Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: thongsyho <thong.ho.px@rvc.renesas.com> Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If SSI uses shared pin, some SSI will be used as parent SSI.
Then, normal SSI's remove and Parent SSI's remove
(these are same SSI) will be called when unbind or remove timing.
In this case, free_irq() will be called twice.
This patch solve this issue.
In case cpu could not be found the error message would always refer to
/codec/ not being found in DT. Fix this by catching the cpu node not found
case explicitly.
Signed-off-by: Julian Scheel <julian@jusst.de> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: thongsyho <thong.ho.px@rvc.renesas.com> Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ]
... basically doing exactly what we do for VMX:
- Passthrough SPEC_CTRL to guests (if enabled in guest CPUID)
- Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest
actually used it.
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Based on a patch from Ashok Raj <ashok.raj@intel.com> ]
Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for
guests that will only mitigate Spectre V2 through IBRS+IBPB and will not
be using a retpoline+IBPB based approach.
To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for
guests that do not actually use the MSR, only start saving and restoring
when a non-zero is written to it.
No attempt is made to handle STIBP here, intentionally. Filtering STIBP
may be added in a future patch, which may require trapping all writes
if we don't want to pass it through directly to the guest.
[dwmw2: Clean up CPUID bits, save/restore manually, handle reset]
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-5-git-send-email-karahmed@amazon.de Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO
(bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the
contents will come directly from the hardware, but user-space can still
override it.
[dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional]
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Indirect Branch Predictor Barrier (IBPB) is an indirect branch
control mechanism. It keeps earlier branches from influencing
later ones.
Unlike IBRS and STIBP, IBPB does not define a new mode of operation.
It's a command that ensures predicted branch targets aren't used after
the barrier. Although IBRS and IBPB are enumerated by the same CPUID
enumeration, IBPB is very different.
IBPB helps mitigate against three potential attacks:
* Mitigate guests from being attacked by other guests.
- This is addressed by issing IBPB when we do a guest switch.
* Mitigate attacks from guest/ring3->host/ring3.
These would require a IBPB during context switch in host, or after
VMEXIT. The host process has two ways to mitigate
- Either it can be compiled with retpoline
- If its going through context switch, and has set !dumpable then
there is a IBPB in that path.
(Tim's patch: https://patchwork.kernel.org/patch/10192871)
- The case where after a VMEXIT you return back to Qemu might make
Qemu attackable from guest when Qemu isn't compiled with retpoline.
There are issues reported when doing IBPB on every VMEXIT that resulted
in some tsc calibration woes in guest.
* Mitigate guest/ring0->host/ring0 attacks.
When host kernel is using retpoline it is safe against these attacks.
If host kernel isn't using retpoline we might need to do a IBPB flush on
every VMEXIT.
Even when using retpoline for indirect calls, in certain conditions 'ret'
can use the BTB on Skylake-era CPUs. There are other mitigations
available like RSB stuffing/clearing.
* IBPB is issued only for SVM during svm_free_vcpu().
VMX has a vmclear and SVM doesn't. Follow discussion here:
https://lkml.org/lkml/2018/1/15/146
Please refer to the following spec for more details on the enumeration
and control.
Refer here to get documentation about mitigations.
[peterz: rebase and changelog rewrite]
[karahmed: - rebase
- vmx: expose PRED_CMD if guest has it in CPUID
- svm: only pass through IBPB if guest has it in CPUID
- vmx: support !cpu_has_vmx_msr_bitmap()]
- vmx: support nested]
[dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS)
PRED_CMD is a write-only MSR]
Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: kvm@vger.kernel.org Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Place the MSR bitmap in struct loaded_vmcs, and update it in place
every time the x2apic or APICv state can change. This is rare and
the loop can handle 64 MSRs per iteration, in a similar fashion as
nested_vmx_prepare_msr_bitmap.
This prepares for choosing, on a per-VM basis, whether to intercept
the SPEC_CTRL and PRED_CMD MSRs.
Cc: stable@vger.kernel.org # prereq for Spectre mitigation Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The potential performance advantages of a vmcs02 pool have never been
realized. To simplify the code, eliminate the pool. Instead, a single
vmcs02 is allocated per VCPU when the VCPU enters VMX operation.
Cc: stable@vger.kernel.org # prereq for Spectre mitigation Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Ameya More <ameya.more@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The host physical addresses of L1's Virtual APIC Page and Posted
Interrupt descriptor are loaded into the VMCS02. The CPU may write
to these pages via their host physical address while L2 is running,
bypassing address-translation-based dirty tracking (e.g. EPT write
protection). Mark them dirty on every exit from L2 to prevent them
from getting out of sync with dirty tracking.
Also mark the virtual APIC page and the posted interrupt descriptor
dirty when KVM is virtualizing posted interrupt processing.
Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I'm seeing build failures from the two newly introduced arrays that
are marked 'const' and '__initdata', which are mutually exclusive:
arch/x86/kernel/cpu/common.c:882:43: error: 'cpu_no_speculation' causes a section type conflict with 'e820_table_firmware_init'
arch/x86/kernel/cpu/common.c:895:43: error: 'cpu_no_meltdown' causes a section type conflict with 'e820_table_firmware_init'
The correct annotation is __initconst.
Fixes: fec9434a12f3 ("x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Thomas Garnier <thgarnie@google.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180202213959.611210-1-arnd@arndb.de Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's no point in building init code with retpolines, since it runs before
any potentially hostile userspace does. And before the retpoline is actually
ALTERNATIVEd into place, for much of it.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: karahmed@amazon.de Cc: peterz@infradead.org Cc: bp@alien8.de Link: https://lkml.kernel.org/r/1517484441-1420-2-git-send-email-dwmw@amazon.co.uk Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 75f139aaf896 "KVM: x86: Add memory barrier on vmcs field lookup"
added a raw 'asm("lfence");' to prevent a bounds check bypass of
'vmcs_field_to_offset_table'.
The lfence can be avoided in this path by using the array_index_nospec()
helper designed for these types of fixes.
Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Andrew Honig <ahonig@google.com> Cc: kvm@vger.kernel.org Cc: Jim Mattson <jmattson@google.com> Link: https://lkml.kernel.org/r/151744959670.6342.3001723920950249067.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'noreplace-paravirt' option disables paravirt patching, leaving the
original pv indirect calls in place.
That's highly incompatible with retpolines, unless we want to uglify
paravirt even further and convert the paravirt calls to retpolines.
As far as I can tell, the option doesn't seem to be useful for much
other than introducing surprising corner cases and making the kernel
vulnerable to Spectre v2. It was probably a debug option from the early
paravirt days. So just remove it.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dan Williams <dan.j.williams@intel.com> Link: https://lkml.kernel.org/r/20180131041333.2x6blhxirc2kclrq@treble Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Despite the fact that all the other code there seems to be doing it, just
using set_cpu_cap() in early_intel_init() doesn't actually work.
For CPUs with PKU support, setup_pku() calls get_cpu_cap() after
c->c_init() has set those feature bits. That resets those bits back to what
was queried from the hardware.
Turning the bits off for bad microcode is easy to fix. That can just use
setup_clear_cpu_cap() to force them off for all CPUs.
I was less keen on forcing the feature bits *on* that way, just in case
of inconsistencies. I appreciate that the kernel is going to get this
utterly wrong if CPU features are not consistent, because it has already
applied alternatives by the time secondary CPUs are brought up.
But at least if setup_force_cpu_cap() isn't being used, we might have a
chance of *detecting* the lack of the corresponding bit and either
panicking or refusing to bring the offending CPU online.
So ensure that the appropriate feature bits are set within get_cpu_cap()
regardless of how many extra times it's called.
Fixes: 2961298e ("x86/cpufeatures: Clean up Spectre v2 related CPUID flags") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: karahmed@amazon.de Cc: peterz@infradead.org Cc: bp@alien8.de Link: https://lkml.kernel.org/r/1517322623-15261-1-git-send-email-dwmw@amazon.co.uk Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reflect the presence of get_user(), __get_user(), and 'syscall' protections
in sysfs. The expectation is that new and better tooling will allow the
kernel to grow more usages of array_index_nospec(), for now, only claim
mitigation for __user pointer de-references.
Reported-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727420158.33451.11658324346540434635.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wireless drivers rely on parse_txq_params to validate that txq_params->ac
is less than NL80211_NUM_ACS by the time the low-level driver's ->conf_tx()
handler is called. Use a new helper, array_index_nospec(), to sanitize
txq_params->ac with respect to speculation. I.e. ensure that any
speculation into ->conf_tx() handlers is done with a value of
txq_params->ac that is within the bounds of [0, NL80211_NUM_ACS).
Reported-by: Christian Lamparter <chunkeey@gmail.com> Reported-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Johannes Berg <johannes@sipsolutions.net> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: linux-wireless@vger.kernel.org Cc: torvalds@linux-foundation.org Cc: "David S. Miller" <davem@davemloft.net> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727419584.33451.7700736761686184303.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'fd' is a user controlled value that is used as a data dependency to
read from the 'fdt->fd' array. In order to avoid potential leaks of
kernel memory values, block speculative execution of the instruction
stream that could issue reads based on an invalid 'file *' returned from
__fcheck_files.
Co-developed-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727418500.33451.17392199002892248656.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The syscall table base is a user controlled function pointer in kernel
space. Use array_index_nospec() to prevent any out of bounds speculation.
While retpoline prevents speculating into a userspace directed target it
does not stop the pointer de-reference, the concern is leaking memory
relative to the syscall table base, by observing instruction cache
behavior.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Andy Lutomirski <luto@kernel.org> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727417984.33451.1216731042505722161.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I do think that it would be a good idea to very expressly document
the fact that it's not that the user access itself is unsafe. I do
agree that things like "get_user()" want to be protected, but not
because of any direct bugs or problems with get_user() and friends,
but simply because get_user() is an excellent source of a pointer
that is obviously controlled from a potentially attacking user
space. So it's a prime candidate for then finding _subsequent_
accesses that can then be used to perturb the cache.
Unlike the __get_user() case get_user() includes the address limit check
near the pointer de-reference. With that locality the speculation can be
mitigated with pointer narrowing rather than a barrier, i.e.
array_index_nospec(). Where the narrowing is performed by:
cmp %limit, %ptr
sbb %mask, %mask
and %mask, %ptr
With respect to speculation the value of %ptr is either less than %limit
or NULL.
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727417469.33451.11804043010080838495.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I do think that it would be a good idea to very expressly document
the fact that it's not that the user access itself is unsafe. I do
agree that things like "get_user()" want to be protected, but not
because of any direct bugs or problems with get_user() and friends,
but simply because get_user() is an excellent source of a pointer
that is obviously controlled from a potentially attacking user
space. So it's a prime candidate for then finding _subsequent_
accesses that can then be used to perturb the cache.
__uaccess_begin_nospec() covers __get_user() and copy_from_iter() where the
limit check is far away from the user pointer de-reference. In those cases
a barrier_nospec() prevents speculation with a potential pointer to
privileged memory. uaccess_try_nospec covers get_user_try.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727416953.33451.10508284228526170604.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for converting some __uaccess_begin() instances to
__uacess_begin_nospec(), make sure all 'from user' uaccess paths are
using the _begin(), _end() helpers rather than open-coded stac() and
clac().
No functional changes.
Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727416438.33451.17309465232057176966.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For __get_user() paths, do not allow the kernel to speculate on the value
of a user controlled pointer. In addition to the 'stac' instruction for
Supervisor Mode Access Protection (SMAP), a barrier_nospec() causes the
access_ok() result to resolve in the pipeline before the CPU might take any
speculative action on the pointer value. Given the cost of 'stac' the
speculation barrier is placed after 'stac' to hopefully overlap the cost of
disabling SMAP with the cost of flushing the instruction pipeline.
Since __get_user is a major kernel interface that deals with user
controlled pointers, the __uaccess_begin_nospec() mechanism will prevent
speculative execution past an access_ok() permission check. While
speculative execution past access_ok() is not enough to lead to a kernel
memory leak, it is a necessary precondition.
To be clear, __uaccess_begin_nospec() is addressing a class of potential
problems near __get_user() usages.
Note, that while the barrier_nospec() in __uaccess_begin_nospec() is used
to protect __get_user(), pointer masking similar to array_index_nospec()
will be used for get_user() since it incorporates a bounds check near the
usage.
uaccess_try_nospec provides the same mechanism for get_user_try.
No functional changes.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Andi Kleen <ak@linux.intel.com> Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727415922.33451.5796614273104346583.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rename the open coded form of this instruction sequence from
rdtsc_ordered() into a generic barrier primitive, barrier_nospec().
One of the mitigations for Spectre variant1 vulnerabilities is to fence
speculative execution after successfully validating a bounds check. I.e.
force the result of a bounds check to resolve in the instruction pipeline
to ensure speculative execution honors that result before potentially
operating on out-of-bounds data.
No functional changes.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Andi Kleen <ak@linux.intel.com> Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727415361.33451.9049453007262764675.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
array_index_nospec() uses a mask to sanitize user controllable array
indexes, i.e. generate a 0 mask if 'index' >= 'size', and a ~0 mask
otherwise. While the default array_index_mask_nospec() handles the
carry-bit from the (index - size) result in software.
The x86 array_index_mask_nospec() does the same, but the carry-bit is
handled in the processor CF flag without conditional instructions in the
control flow.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727414808.33451.1873237130672785331.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
array_index_nospec() is proposed as a generic mechanism to mitigate
against Spectre-variant-1 attacks, i.e. an attack that bypasses boundary
checks via speculative execution. The array_index_nospec()
implementation is expected to be safe for current generation CPUs across
multiple architectures (ARM, x86).
Based on an original implementation by Linus Torvalds, tweaked to remove
speculative flows by Alexei Starovoitov, and tweaked again by Linus to
introduce an x86 assembly implementation for the mask generation.
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org> Co-developed-by: Alexei Starovoitov <ast@kernel.org> Suggested-by: Cyril Novikov <cnovikov@lynx.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727414229.33451.18411580953862676575.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The TS_COMPAT bit is very hot and is accessed from code paths that mostly
also touch thread_info::flags. Move it into struct thread_info to improve
cache locality.
The only reason it was in thread_struct is that there was a brief period
during which arch-specific fields were not allowed in struct thread_info.
Linus suggested further changing:
ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
to:
if (unlikely(ti->status & (TS_COMPAT|TS_I386_REGS_POKED)))
ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
on the theory that frequently dirtying the cacheline even in pure 64-bit
code that never needs to modify status hurts performance. That could be a
reasonable followup patch, but I suspect it matters less on top of this
patch.
The SYCALLL64 fast path was a nice, if small, optimization back in the good
old days when syscalls were actually reasonably fast. Now there is PTI to
slow everything down, and indirect branches are verboten, making everything
messier. The retpoline code in the fast path is particularly nasty.
Just get rid of the fast path. The slow path is barely slower.
[ tglx: Split out the 'push all extra regs' part ]
The spectre_v2 option 'auto' does not check whether CONFIG_RETPOLINE is
enabled. As a consequence it fails to emit the appropriate warning and sets
feature flags which have no effect at all.
We want to expose the hardware features simply in /proc/cpuinfo as "ibrs",
"ibpb" and "stibp". Since AMD has separate CPUID bits for those, use them
as the user-visible bits.
When the Intel SPEC_CTRL bit is set which indicates both IBRS and IBPB
capability, set those (AMD) bits accordingly. Likewise if the Intel STIBP
bit is set, set the AMD STIBP that's used for the generic hardware
capability.
Hide the rest from /proc/cpuinfo by putting "" in the comments. Including
RETPOLINE and RETPOLINE_AMD which shouldn't be visible there. There are
patches to make the sysfs vulnerabilities information non-readable by
non-root, and the same should apply to all information about which
mitigations are actually in use. Those *shouldn't* appear in /proc/cpuinfo.
The feature bit for whether IBPB is actually used, which is needed for
ALTERNATIVEs, is renamed to X86_FEATURE_USE_IBPB.
This doesn't refuse to load the affected microcodes; it just refuses to
use the Spectre v2 mitigation features if they're detected, by clearing
the appropriate feature bits.
The AMD CPUID bits are handled here too, because hypervisors *may* have
been exposing those bits even on Intel chips, for fine-grained control
of what's available.
It is non-trivial to use x86_match_cpu() for this table because that
doesn't handle steppings. And the approach taken in commit bd9240a18
almost made me lose my lunch.
Also, for CPUs which don't speculate at all, don't report that they're
vulnerable to the Spectre variants either.
Leave the cpu_no_meltdown[] match table with just X86_VENDOR_AMD in it
for now, even though that could be done with a simple comparison, on the
assumption that we'll have more to add.
Based on suggestions from Dave Hansen and Alan Cox.
This is a pure feature bits leaf. There are two AVX512 feature bits in it
already which were handled as scattered bits, and three more from this leaf
are going to be added for speculation control features.
There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.
To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.
If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.
[ tglx: Massaged changelog ]
Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: jeyu@kernel.org Cc: arjan@linux.intel.com Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: rga@amazon.de Cc: Dave Hansen <dave.hansen@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: https://lkml.kernel.org/r/20180125095843.595615683@infradead.org
[dwmw2: Use ASM_CALL_CONSTRAINT like upstream, now we have it] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It doesn't make sense to have an indirect call thunk with esp/rsp as
retpoline code won't work correctly with the stack pointer register.
Removing it will help compiler writers to catch error in case such
a thunk call is emitted incorrectly.
Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") Suggested-by: Jeff Law <law@redhat.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1516658974-27852-1-git-send-email-longman@redhat.com Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer. Fix this by using strncmp() instead of memcmp(). [Also
clean up the code to deduplicate some logic.]
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Jin Qian <jinqian@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some firmware entries were forgotten to be added via MODULE_FIRMWARE(), which
may result in the non-functional state when the driver is loaded in initrd.
Link: http://bugzilla.opensuse.org/show_bug.cgi?id=1037344 Fixes: 15be8e89cdd9 ("b43: add more bcma cores") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Doing so is completely void of sense for multiple reasons so prevent
it. Set dis_ucode_ldr to true and thus disable the microcode loader by
default to address xen pv guests which execute the AP path but not the
BSP path.
By having it turned off by default, the APs won't run into the loader
either.
Also, check CPUID(1).ECX[31] which hypervisors set. Well almost, not the
xen pv one. That one gets the aforementioned "fix".
Also, improve the detection method by caching the final decision whether
to continue loading in dis_ucode_ldr and do it once on the BSP. The APs
then simply test that value.
Despite the absurdity of it backing up and restoring the stack pointer
for no reason, the bug is actually the fact that it's only backing up
and restoring the lower 32 bits of the stack pointer. The upper 32 bits
are getting cleared out, corrupting the stack pointer.
So change the '__asm_call_sp' register variable to be associated with
the actual full-size stack pointer.
This also requires changing the __ASM_SEL() macro to be based on the
actual compiled arch size, rather than the CONFIG value, because
CONFIG_X86_64 compiles some files with '-m32' (e.g., realmode and vdso).
Otherwise Clang fails to build the kernel because it complains about the
use of a 64-bit register (RSP) in a 32-bit file.
reuseport_add_sock() needs to deal with attaching a socket having
its own sk_reuseport_cb, after a prior
setsockopt(SO_ATTACH_REUSEPORT_?BPF)
Without this fix, not only a WARN_ONCE() was issued, but we were also
leaking memory.
Thanks to sysbot and Eric Biggers for providing us nice C repros.
------------[ cut here ]------------
socket already in reuseport group
WARNING: CPU: 0 PID: 3496 at net/core/sock_reuseport.c:119
reuseport_add_sock+0x742/0x9b0 net/core/sock_reuseport.c:117
Kernel panic - not syncing: panic_on_warn set ...
If a sk_v6_rcv_saddr is !IPV6_ADDR_ANY and !IPV6_ADDR_MAPPED, it
implicitly implies it is an ipv6only socket. However, in inet6_bind(),
this addr_type checking and setting sk->sk_ipv6only to 1 are only done
after sk->sk_prot->get_port(sk, snum) has been completed successfully.
This inconsistency between sk_v6_rcv_saddr and sk_ipv6only confuses
the 'get_port()'.
In particular, when binding SO_REUSEPORT UDP sockets,
udp_reuseport_add_sock(sk,...) is called. udp_reuseport_add_sock()
checks "ipv6_only_sock(sk2) == ipv6_only_sock(sk)" before adding sk to
sk2->sk_reuseport_cb. In this case, ipv6_only_sock(sk2) could be
1 while ipv6_only_sock(sk) is still 0 here. The end result is,
reuseport_alloc(sk) is called instead of adding sk to the existing
sk2->sk_reuseport_cb.
It can be reproduced by binding two SO_REUSEPORT UDP sockets on an
IPv6 address (!ANY and !MAPPED). Only one of the socket will
receive packet.
The fix is to set the implicit sk_ipv6only before calling get_port().
The original sk_ipv6only has to be saved such that it can be restored
in case get_port() failed. The situation is similar to the
inet_reset_saddr(sk) after get_port() has failed.
Thanks to Calvin Owens <calvinowens@fb.com> who created an easy
reproduction which leads to a fix.
Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In a couple of points of the control path, n->ht_down is currently
accessed without the required RCU annotation. The accesses are
safe, but sparse complaints. Since we already held the
rtnl lock, let use rtnl_dereference().
Fixes: a1b7c5fd7fe9 ("net: sched: add cls_u32 offload hooks for netdevs") Fixes: de5df63228fc ("net: sched: cls_u32 changes to knode must appear atomic to readers") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit fixes the pacing_gain to remain at BBR_UNIT (1.0) when
using lt_bw and returning from the PROBE_RTT state to PROBE_BW.
Previously, when using lt_bw, upon exiting PROBE_RTT and entering
PROBE_BW the bbr_reset_probe_bw_mode() code could sometimes randomly
end up with a cycle_idx of 0 and hence have bbr_advance_cycle_phase()
set a pacing gain above 1.0. In such cases this would result in a
pacing rate that is 1.25x higher than intended, potentially resulting
in a high loss rate for a little while until we stop using the lt_bw a
bit later.
This commit is a stable candidate for kernels back as far as 4.9.
We don't stop device before reset owner, this means we could try to
serve any virtqueue kick before reset dev->worker. This will result a
warn since the work was pending at llist during owner resetting. Fix
this by stopping device during owner reset.
Reported-by: syzbot+eb17c6162478cc50632c@syzkaller.appspotmail.com Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
socket can be disconnected and gets transformed back to a listening
socket, if sk_frag.page is not released, which will be cloned into
a new socket by sk_clone_lock, but the reference count of this page
is increased, lead to a use after free or double free issue
Signed-off-by: Li RongQing <lirongqing@baidu.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Driver check the wrong register bit in rtl_ocp_tx_cond() that keep driver
waiting until timeout.
Fix this by waiting for the right register bit.
Signed-off-by: Chunhao Lin <hau@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Quectel EP06 is a Cat. 6 LTE modem. It uses the same interface as
the EC20/EC25 for QMI, and requires the same "set DTR"-quirk to work.
Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com> Acked-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following soft lockup was caught. This is a deadlock caused by
recusive locking.
Process kworker/u40:1:28016 was holding spin lock "mbx->queue_lock" in
qlcnic_83xx_mailbox_worker(), while a softirq came in and ask the same spin
lock in qlcnic_83xx_enqueue_mbx_cmd(). This lock should be hold by disable
bh..
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: a46182b00290 ("net: igmp: Use correct source address on IGMPv3 reports") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we dump the ip6mr mfc entries via proc, we initialize an iterator
with the table to dump but we don't clear the cache pointer which might
be initialized from a prior read on the same descriptor that ended. This
can result in lock imbalance (an unnecessary unlock) leading to other
crashes and hangs. Clear the cache pointer like ipmr does to fix the issue.
Thanks for the reliable reproducer.
Here's syzbot's trace:
WARNING: bad unlock balance detected!
4.15.0-rc3+ #128 Not tainted
syzkaller971460/3195 is trying to release lock (mrt_lock) at:
[<000000006898068d>] ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
but there are no more locks to release!
other info that might help us debug this:
1 lock held by syzkaller971460/3195:
#0: (&p->lock){+.+.}, at: [<00000000744a6565>] seq_read+0xd5/0x13d0
fs/seq_file.c:165
Reported-by: syzbot <bot+eceb3204562c41a438fa1f2335e0fe4f6886d669@syzkaller.appspotmail.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
setserial changes the IRQ via uart_set_info(). It invokes
uart_shutdown() which free the current used IRQ and clear
TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke
uart_startup() before returning to the caller leaving
TTY_PORT_INITIALIZED cleared.
The next open will crash with
| list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98.
since the close from the IOCTL won't free the IRQ (and clean the list)
due to the TTY_PORT_INITIALIZED check in uart_shutdown().
There is same pattern in uart_do_autoconfig() and I *think* it also
needs to set TTY_PORT_INITIALIZED there.
Is there a reason why uart_startup() does not set the flag by itself
after the IRQ has been acquired (since it is cleared in uart_shutdown)?
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hugh Dickins [Tue, 30 Jan 2018 02:17:58 +0000 (18:17 -0800)]
kaiser: allocate pgd with order 0 when pti=off
The 4.9.77 version of "x86/pti/efi: broken conversion from efi to kernel
page table" looked nicer than the 4.4.112 version, but was suboptimal on
machines booted with "pti=off" (or on AMD machines): it allocated pgd
with an order 1 page whatever the setting of kaiser_enabled.
Fix that by moving the definition of PGD_ALLOCATION_ORDER from
asm/pgalloc.h to asm/pgtable.h, which already defines kaiser_enabled.
Fixes: 1b92c48a2eeb ("x86/pti/efi: broken conversion from efi to kernel page table") Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The inital fix for trusted boot and PTI potentially misses the pgd clearing
if pud_alloc() sets a PGD. It probably works in *practice* because for two
adjacent calls to map_tboot_page() that share a PGD entry, the first will
clear NX, *then* allocate and set the PGD (without NX clear). The second
call will *not* allocate but will clear the NX bit.
Defer the NX clearing to a point after it is known that all top-level
allocations have occurred. Add a comment to clarify why.
[ tglx: Massaged changelog ]
[ hughd notes: I have not tested tboot, but this looks to me as necessary
and as safe in old-Kaiser backports as it is upstream; I'm not submitting
the commit-to-be-fixed 262b6b30087, since it was undone by 445b69e3b75e,
and makes conflict trouble because of 5-level's p4d versus 4-level's pgd.]
Hugh Dickins [Tue, 30 Jan 2018 02:16:55 +0000 (18:16 -0800)]
kaiser: fix intel_bts perf crashes
Vince reported perf_fuzzer quickly locks up on 4.15-rc7 with PTI;
Robert reported Bad RIP with KPTI and Intel BTS also on 4.15-rc7:
honggfuzz -f /tmp/somedirectorywithatleastonefile \
--linux_perf_bts_edge -s -- /bin/true
(honggfuzz from https://github.com/google/honggfuzz) crashed with
BUG: unable to handle kernel paging request at ffff9d3215100000
(then narrowed it down to
perf record --per-thread -e intel_bts//u -- /bin/ls).
The intel_bts driver does not use the 'normal' BTS buffer which is
exposed through kaiser_add_mapping(), but instead uses the memory
allocated for the perf AUX buffer.
This obviously comes apart when using PTI, because then the kernel
mapping, which includes that AUX buffer memory, disappears while
switched to user page tables.
Easily fixed in old-Kaiser backports, by applying kaiser_add_mapping()
to those pages; perhaps not so easy for upstream, where 4.15-rc8 commit 99a9dc98ba52 ("x86,perf: Disable intel_bts when PTI") disables for now.
Slightly reorganized surrounding code in bts_buffer_setup_aux(),
so it can better match bts_buffer_free_aux(): free_aux with an #ifdef
to avoid the loop when PTI is off, but setup_aux needs to loop anyway
(and kaiser_add_mapping() is cheap when PTI config is off or "pti=off").
The recent commit 87590ce6e373 ("sysfs/cpu: Add vulnerability folder")
added a generic folder and set of files for reporting information on
CPU vulnerabilities. One of those was for meltdown:
/sys/devices/system/cpu/vulnerabilities/meltdown
This commit wires up that file for 64-bit Book3S powerpc.
For now we default to "Vulnerable" unless the RFI flush is enabled.
That may not actually be true on all hardware, further patches will
refine the reporting based on the CPU/platform etc. But for now we
default to being pessimists.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
New device-tree properties are available which tell the hypervisor
settings related to the RFI flush. Use them to determine the
appropriate flush instruction to use, and whether the flush is
required.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A new hypervisor call is available which tells the guest settings
related to the RFI flush. Use it to query the appropriate flush
instruction(s), and whether the flush is required.
Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because there may be some performance overhead of the RFI flush, add
kernel command line options to disable it.
We add a sensibly named 'no_rfi_flush' option, but we also hijack the
x86 option 'nopti'. The RFI flush is not the same as KPTI, but if we
see 'nopti' we can guess that the user is trying to avoid any overhead
of Meltdown mitigations, and it means we don't have to educate every
one about a different command line option.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On some CPUs we can prevent the Meltdown vulnerability by flushing the
L1-D cache on exit from kernel to user mode, and from hypervisor to
guest.
This is known to be the case on at least Power7, Power8 and Power9. At
this time we do not know the status of the vulnerability on other CPUs
such as the 970 (Apple G5), pasemi CPUs (AmigaOne X1000) or Freescale
CPUs. As more information comes to light we can enable this, or other
mechanisms on those CPUs.
The vulnerability occurs when the load of an architecturally
inaccessible memory region (eg. userspace load of kernel memory) is
speculatively executed to the point where its result can influence the
address of a subsequent speculatively executed load.
In order for that to happen, the first load must hit in the L1,
because before the load is sent to the L2 the permission check is
performed. Therefore if no kernel addresses hit in the L1 the
vulnerability can not occur. We can ensure that is the case by
flushing the L1 whenever we return to userspace. Similarly for
hypervisor vs guest.
In order to flush the L1-D cache on exit, we add a section of nops at
each (h)rfi location that returns to a lower privileged context, and
patch that with some sequence. Newer firmwares are able to advertise
to us that there is a special nop instruction that flushes the L1-D.
If we do not see that advertised, we fall back to doing a displacement
flush in software.
For guest kernels we support migration between some CPU versions, and
different CPUs may use different flush instructions. So that we are
prepared to migrate to a machine with a different flush instruction
activated, we may have to patch more than one flush instruction at
boot if the hypervisor tells us to.
In the end this patch is mostly the work of Nicholas Piggin and
Michael Ellerman. However a cast of thousands contributed to analysis
of the issue, earlier versions of the patch, back ports testing etc.
Many thanks to all of them.
Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[Balbir - back ported to stable with changes] Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the SLB miss handler we may be returning to user or kernel. We need
to add a check early on and save the result in the cr4 register, and
then we bifurcate the return path based on that.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Backport to 4.4 based on patch from Balbir] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the syscall exit path we may be returning to user or kernel
context. We already have a test for that, because we conditionally
restore r13. So use that existing test and branch, and bifurcate the
return based on that.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Similar to the syscall return path, in fast_exception_return we may be
returning to user or kernel context. We already have a test for that,
because we conditionally restore r13. So use that existing test and
branch, and bifurcate the return based on that.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The rfid/hrfid ((Hypervisor) Return From Interrupt) instruction is
used for switching from the kernel to userspace, and from the
hypervisor to the guest kernel. However it can and is also used for
other transitions, eg. from real mode kernel code to virtual mode
kernel code, and it's not always clear from the code what the
destination context is.
To make it clearer when reading the code, add macros which encode the
expected destination context.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A new hypervisor call has been defined to communicate various
characteristics of the CPU to guests. Add definitions for the hcall
number, flags and a wrapper function.
Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[Balbir fixed conflicts in backport] Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since clocks are disabled except during message transfer clocks
are also disabled when spi_imx_remove gets called. Accessing
registers leads to a freeeze at least on a i.MX 6ULL. Enable
clocks before disabling accessing the MXC_CSPICTRL register.
Fixes: 9e556dcc55774 ("spi: spi-imx: only enable the clocks when we start to transfer a message") Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS
lines, so only allow such wakeup method when the system actually has
RTS/CTS support.
Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD") Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Martin Kaiser <martin@kaiser.cx> Acked-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vhci_hcd clears all the bits port_status bits instead of clearing
just the USB_PORT_STAT_POWER bit when it handles ClearPortFeature:
USB_PORT_FEAT_POWER. This causes vhci_hcd attach to fail in a bad
state, leaving device unusable by the client. The device is still
attached and however client can't use it.
The problem was fixed as part of larger change to add USB3 Super
Speed support. This patch backports just the change to clear the
USB_PORT_STAT_POWER.
The current code tries to test for bits that are masked out by
usb_endpoint_maxp(). Instead, use the proper accessor to access
the new high bandwidth bits.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If we return 1 from our post_reset handler, then our disconnect handler
will be called immediately afterwards. Since pre_reset blocks all scsi
requests our disconnect handler will then hang in the scsi_remove_host
call.
This is esp. bad because our disconnect handler hanging for ever also
stops the USB subsys from enumerating any new USB devices, causes commands
like lsusb to hang, etc.
In practice this happens when unplugging some uas devices because the hub
code may see the device as needing a warm-reset and calls usb_reset_device
before seeing the disconnect. In this case uas_configure_endpoints fails
with -ENODEV. We do not want to print an error for this, so this commit
also silences the shost_printk for -ENODEV.
ENDQUOTE
However, if we do that we better drop any unconditional execution
and report to the SCSI subsystem that we have undergone a reset
but we are not operational now.
Signed-off-by: Oliver Neukum <oneukum@suse.com> Reported-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Upon usb composition switch there is possibility of ep0 file
release happening after gadget driver bind. In case of composition
switch from adb to a non-adb composition gadget will never gets
bound again resulting into failure of usb device enumeration. Fix
this issue by checking FFS_FL_BOUND flag and avoid extra
gadget driver unbind if it is already done as part of composition
switch.
This fixes adb reconnection error reported on Android running
v4.4 and above kernel versions. Verified on Hikey running vanilla
v4.15-rc7 + few out of tree Mali patches.
projects / linux-stable / log