linux-toradex.git/arch, branch v4.4.90

swiotlb-xen: implement xen_swiotlb_dma_mmap callback

2017-10-05T07:41:48+00:00

commit 7e91c7df29b5e196de3dc6f086c8937973bd0b88 upstream.

This function creates userspace mapping for the DMA-coherent memory.

Signed-off-by: Stefano Stabellini 
Signed-off-by: Oleksandr Dmytryshyn 
Signed-off-by: Andrii Anisov 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: use cmpxchg64

2017-10-05T07:41:48+00:00

commit c0a1666bcb2a33e84187a15eabdcd54056be9a97 upstream.

This fixes a compilation failure on 32-bit systems.

Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

ARM: pxa: fix the number of DMA requestor lines

2017-10-05T07:41:48+00:00

commit 4c35430ad18f5a034302cb90e559ede5a27f93b9 upstream.

The number of requestor lines was clamped to 0 for all pxa architectures
in the requestor declaration. Fix this by using the value.

Fixes: 72b195cb7162 ("ARM: pxa: add the number of DMA requestor lines")
Signed-off-by: Robert Jarzmik 
Signed-off-by: Greg Kroah-Hartman

ARM: pxa: add the number of DMA requestor lines

2017-10-05T07:41:48+00:00

commit 72b195cb716284217e8b270af420bc7e5cf04b3c upstream.

Declare the number of DMA requestor lines per platform :
 - for pxa25x: 40 requestor lines
 - for pxa27x: 75 requestor lines
 - for pxa3xx: 100 requestor lines

This information will be used to activate the DMA flow control or not.

Signed-off-by: Robert Jarzmik 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: remove WARN_ON_ONCE in kvm_vcpu_trigger_posted_interrupt

2017-10-05T07:41:47+00:00

commit 5753743fa5108b8f98bd61e40dc63f641b26c768 upstream.

WARN_ON_ONCE(pi_test_sn(&vmx->pi_desc)) in kvm_vcpu_trigger_posted_interrupt()
intends to detect the violation of invariant that VT-d PI notification
event is not suppressed when vcpu is in the guest mode. Because the
two checks for the target vcpu mode and the target suppress field
cannot be performed atomically, the target vcpu mode may change in
between. If that does happen, WARN_ON_ONCE() here may raise false
alarms.

As the previous patch fixed the real invariant breaker, remove this
WARN_ON_ONCE() to avoid false alarms, and document the allowed cases
instead.

Signed-off-by: Haozhong Zhang 
Reported-by: "Ramamurthy, Venkatesh" 
Reported-by: Dan Williams 
Reviewed-by: Paolo Bonzini 
Fixes: 28b835d60fcc ("KVM: Update Posted-Interrupts Descriptor when vCPU is preempted")
Signed-off-by: Radim Krčmář 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: do not change SN bit in vmx_update_pi_irte()

2017-10-05T07:41:47+00:00

commit dc91f2eb1a4021eb6705c15e474942f84ab9b211 upstream.

In kvm_vcpu_trigger_posted_interrupt() and pi_pre_block(), KVM
assumes that PI notification events should not be suppressed when the
target vCPU is not blocked.

vmx_update_pi_irte() sets the SN field before changing an interrupt
from posting to remapping, but it does not check the vCPU mode.
Therefore, the change of SN field may break above the assumption.
Besides, I don't see reasons to suppress notification events here, so
remove the changes of SN field to avoid race condition.

Signed-off-by: Haozhong Zhang 
Reported-by: "Ramamurthy, Venkatesh" 
Reported-by: Dan Williams 
Reviewed-by: Paolo Bonzini 
Fixes: 28b835d60fcc ("KVM: Update Posted-Interrupts Descriptor when vCPU is preempted")
Signed-off-by: Radim Krčmář 
Signed-off-by: Greg Kroah-Hartman

x86/fpu: Don't let userspace set bogus xcomp_bv

2017-10-05T07:41:47+00:00

commit 814fb7bb7db5433757d76f4c4502c96fc53b0b5e upstream.

[Please apply to 4.4-stable.  Note: the backport includes the
fpstate_init() call in xstateregs_set(), since fix is useless without
it.  It was added by commit 91c3dba7dbc1 ("x86/fpu/xstate: Fix PTRACE
frames for XSAVES"), but it doesn't make sense to backport that whole
commit.]

On x86, userspace can use the ptrace() or rt_sigreturn() system calls to
set a task's extended state (xstate) or "FPU" registers.  ptrace() can
set them for another task using the PTRACE_SETREGSET request with
NT_X86_XSTATE, while rt_sigreturn() can set them for the current task.
In either case, registers can be set to any value, but the kernel
assumes that the XSAVE area itself remains valid in the sense that the
CPU can restore it.

However, in the case where the kernel is using the uncompacted xstate
format (which it does whenever the XSAVES instruction is unavailable),
it was possible for userspace to set the xcomp_bv field in the
xstate_header to an arbitrary value.  However, all bits in that field
are reserved in the uncompacted case, so when switching to a task with
nonzero xcomp_bv, the XRSTOR instruction failed with a #GP fault.  This
caused the WARN_ON_FPU(err) in copy_kernel_to_xregs() to be hit.  In
addition, since the error is otherwise ignored, the FPU registers from
the task previously executing on the CPU were leaked.

Fix the bug by checking that the user-supplied value of xcomp_bv is 0 in
the uncompacted case, and returning an error otherwise.

The reason for validating xcomp_bv rather than simply overwriting it
with 0 is that we want userspace to see an error if it (incorrectly)
provides an XSAVE area in compacted format rather than in uncompacted
format.

Note that as before, in case of error we clear the task's FPU state.
This is perhaps non-ideal, especially for PTRACE_SETREGSET; it might be
better to return an error before changing anything.  But it seems the
"clear on error" behavior is fine for now, and it's a little tricky to
do otherwise because it would mean we couldn't simply copy the full
userspace state into kernel memory in one __copy_from_user().

This bug was found by syzkaller, which hit the above-mentioned
WARN_ON_FPU():

    WARNING: CPU: 1 PID: 0 at ./arch/x86/include/asm/fpu/internal.h:373 __switch_to+0x5b5/0x5d0
    CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.13.0 #453
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    task: ffff9ba2bc8e42c0 task.stack: ffffa78cc036c000
    RIP: 0010:__switch_to+0x5b5/0x5d0
    RSP: 0000:ffffa78cc08bbb88 EFLAGS: 00010082
    RAX: 00000000fffffffe RBX: ffff9ba2b8bf2180 RCX: 00000000c0000100
    RDX: 00000000ffffffff RSI: 000000005cb10700 RDI: ffff9ba2b8bf36c0
    RBP: ffffa78cc08bbbd0 R08: 00000000929fdf46 R09: 0000000000000001
    R10: 0000000000000000 R11: 0000000000000000 R12: ffff9ba2bc8e42c0
    R13: 0000000000000000 R14: ffff9ba2b8bf3680 R15: ffff9ba2bf5d7b40
    FS:  00007f7e5cb10700(0000) GS:ffff9ba2bf400000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00000000004005cc CR3: 0000000079fd5000 CR4: 00000000001406e0
    Call Trace:
    Code: 84 00 00 00 00 00 e9 11 fd ff ff 0f ff 66 0f 1f 84 00 00 00 00 00 e9 e7 fa ff ff 0f ff 66 0f 1f 84 00 00 00 00 00 e9 c2 fa ff ff <0f> ff 66 0f 1f 84 00 00 00 00 00 e9 d4 fc ff ff 66 66 2e 0f 1f

Here is a C reproducer.  The expected behavior is that the program spin
forever with no output.  However, on a buggy kernel running on a
processor with the "xsave" feature but without the "xsaves" feature
(e.g. Sandy Bridge through Broadwell for Intel), within a second or two
the program reports that the xmm registers were corrupted, i.e. were not
restored correctly.  With CONFIG_X86_DEBUG_FPU=y it also hits the above
kernel warning.

    #define _GNU_SOURCE
    #include 
    #include 
    #include 
    #include 
    #include 
    #include 
    #include 
    #include 

    int main(void)
    {
        int pid = fork();
        uint64_t xstate[512];
        struct iovec iov = { .iov_base = xstate, .iov_len = sizeof(xstate) };

        if (pid == 0) {
            bool tracee = true;
            for (int i = 0; i < sysconf(_SC_NPROCESSORS_ONLN) && tracee; i++)
                tracee = (fork() != 0);
            uint32_t xmm0[4] = { [0 ... 3] = tracee ? 0x00000000 : 0xDEADBEEF };
            asm volatile("   movdqu %0, %%xmm0\n"
                         "   mov %0, %%rbx\n"
                         "1: movdqu %%xmm0, %0\n"
                         "   mov %0, %%rax\n"
                         "   cmp %%rax, %%rbx\n"
                         "   je 1b\n"
                         : "+m" (xmm0) : : "rax", "rbx", "xmm0");
            printf("BUG: xmm registers corrupted!  tracee=%d, xmm0=%08X%08X%08X%08X\n",
                   tracee, xmm0[0], xmm0[1], xmm0[2], xmm0[3]);
        } else {
            usleep(100000);
            ptrace(PTRACE_ATTACH, pid, 0, 0);
            wait(NULL);
            ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov);
            xstate[65] = -1;
            ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov);
            ptrace(PTRACE_CONT, pid, 0, 0);
            wait(NULL);
        }
        return 1;
    }

Note: the program only tests for the bug using the ptrace() system call.
The bug can also be reproduced using the rt_sigreturn() system call, but
only when called from a 32-bit program, since for 64-bit programs the
kernel restores the FPU state from the signal frame by doing XRSTOR
directly from userspace memory (with proper error checking).

Reported-by: Dmitry Vyukov 
Signed-off-by: Eric Biggers 
Reviewed-by: Kees Cook 
Reviewed-by: Rik van Riel 
Acked-by: Dave Hansen 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Eric Biggers 
Cc: Fenghua Yu 
Cc: Kevin Hao 
Cc: Linus Torvalds 
Cc: Michael Halcrow 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Wanpeng Li 
Cc: Yu-cheng Yu 
Cc: kernel-hardening@lists.openwall.com
Fixes: 0b29643a5843 ("x86/xsaves: Change compacted format xsave area header")
Link: http://lkml.kernel.org/r/20170922174156.16780-2-ebiggers3@gmail.com
Link: http://lkml.kernel.org/r/20170923130016.21448-25-mingo@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

kvm: nVMX: Don't allow L2 to access the hardware CR8

2017-10-05T07:41:46+00:00

commit 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f upstream.

If L1 does not specify the "use TPR shadow" VM-execution control in
vmcs12, then L0 must specify the "CR8-load exiting" and "CR8-store
exiting" VM-execution controls in vmcs02. Failure to do so will give
the L2 VM unrestricted read/write access to the hardware CR8.

This fixes CVE-2017-12154.

Signed-off-by: Jim Mattson 
Reviewed-by: David Hildenbrand 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: Do not BUG() on out-of-bounds guest IRQ

2017-10-05T07:41:46+00:00

commit 3a8b0677fc6180a467e26cc32ce6b0c09a32f9bb upstream.

The value of the guest_irq argument to vmx_update_pi_irte() is
ultimately coming from a KVM_IRQFD API call. Do not BUG() in
vmx_update_pi_irte() if the value is out-of bounds. (Especially,
since KVM as a whole seems to hang after that.)

Instead, print a message only once if we find that we don't have a
route for a certain IRQ (which can be out-of-bounds or within the
array).

This fixes CVE-2017-1000252.

Fixes: efc644048ecde54 ("KVM: x86: Update IRTE for posted-interrupts")
Signed-off-by: Jan H. Schönherr 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

arm64: fault: Route pte translation faults via do_translation_fault

2017-10-05T07:41:46+00:00

commit 760bfb47c36a07741a089bf6a28e854ffbee7dc9 upstream.

We currently route pte translation faults via do_page_fault, which elides
the address check against TASK_SIZE before invoking the mm fault handling
code. However, this can cause issues with the path walking code in
conjunction with our word-at-a-time implementation because
load_unaligned_zeropad can end up faulting in kernel space if it reads
across a page boundary and runs into a page fault (e.g. by attempting to
read from a guard region).

In the case of such a fault, load_unaligned_zeropad has registered a
fixup to shift the valid data and pad with zeroes, however the abort is
reported as a level 3 translation fault and we dispatch it straight to
do_page_fault, despite it being a kernel address. This results in calling
a sleeping function from atomic context:

  BUG: sleeping function called from invalid context at arch/arm64/mm/fault.c:313
  in_atomic(): 0, irqs_disabled(): 0, pid: 10290
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  [...]
  [] ___might_sleep+0x134/0x144
  [] __might_sleep+0x7c/0x8c
  [] do_page_fault+0x140/0x330
  [] do_mem_abort+0x54/0xb0
  Exception stack(0xfffffffb20247a70 to 0xfffffffb20247ba0)
  [...]
  [] el1_da+0x18/0x78
  [] path_parentat+0x44/0x88
  [] filename_parentat+0x5c/0xd8
  [] filename_create+0x4c/0x128
  [] SyS_mkdirat+0x50/0xc8
  [] el0_svc_naked+0x24/0x28
  Code: 36380080 d5384100 f9400800 9402566d (d4210000)
  ---[ end trace 2d01889f2bca9b9f ]---

Fix this by dispatching all translation faults to do_translation_faults,
which avoids invoking the page fault logic for faults on kernel addresses.

Reported-by: Ankit Jain 
Signed-off-by: Will Deacon 
Signed-off-by: Catalin Marinas 
Signed-off-by: Greg Kroah-Hartman