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  1. 25 Sep, 2022 7 commits
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  7. 22 Sep, 2022 5 commits
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · bf682942
      Linus Torvalds authored 
      Pull SCSI fixes from James Bottomley:
 "Three small and pretty obvious fixes, all in drivers"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: mpt3sas: Fix return value check of dma_get_required_mask()
  scsi: qla2xxx: Fix memory leak in __qlt_24xx_handle_abts()
  scsi: qedf: Fix a UAF bug in __qedf_probe()
      bf682942
    • Linus Torvalds's avatar
      Merge tag 'slab-for-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab · 3c0f396a
      Linus Torvalds authored 
      Pull slab fixes from Vlastimil Babka:

 - Fix a possible use-after-free in SLUB's kmem_cache removal,
   introduced in this cycle, by Feng Tang.

 - WQ_MEM_RECLAIM dependency fix for the workqueue-based cpu slab
   flushing introduced in 5.15, by Maurizio Lombardi.

 - Add missing KASAN hooks in two kmalloc entry paths, by Peter
   Collingbourne.

 - A BUG_ON() removal in SLUB's kmem_cache creation when allocation
   fails (too small to possibly happen in practice, syzbot used fault
   injection), by Chao Yu.

* tag 'slab-for-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context.
  mm/slab_common: fix possible double free of kmem_cache
  kasan: call kasan_malloc() from __kmalloc_*track_caller()
  mm/slub: fix to return errno if kmalloc() fails
      3c0f396a
    • Sean Christopherson's avatar
      KVM: x86: Inject #UD on emulated XSETBV if XSAVES isn't enabled · 50b2d49b
      Sean Christopherson authored 
      Inject #UD when emulating XSETBV if CR4.OSXSAVE is not set.  This also
covers the "XSAVE not supported" check, as setting CR4.OSXSAVE=1 #GPs if
XSAVE is not supported (and userspace gets to keep the pieces if it
forces incoherent vCPU state).

Add a comment to kvm_emulate_xsetbv() to call out that the CPU checks
CR4.OSXSAVE before checking for intercepts.  AMD'S APM implies that #UD
has priority (says that intercepts are checked before #GP exceptions),
while Intel's SDM says nothing about interception priority.  However,
testing on hardware shows that both AMD and Intel CPUs prioritize the #UD
over interception.

Fixes: 02d4160f ("x86: KVM: add xsetbv to the emulator")
Cc: stable@vger.kernel.org
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20220824033057.3576315-4-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      50b2d49b
    • Dr. David Alan Gilbert's avatar
      KVM: x86: Always enable legacy FP/SSE in allowed user XFEATURES · a1020a25
      Dr. David Alan Gilbert authored 
      Allow FP and SSE state to be saved and restored via KVM_{G,SET}_XSAVE on
XSAVE-capable hosts even if their bits are not exposed to the guest via
XCR0.

Failing to allow FP+SSE first showed up as a QEMU live migration failure,
where migrating a VM from a pre-XSAVE host, e.g. Nehalem, to an XSAVE
host failed due to KVM rejecting KVM_SET_XSAVE.  However, the bug also
causes problems even when migrating between XSAVE-capable hosts as
KVM_GET_SAVE won't set any bits in user_xfeatures if XSAVE isn't exposed
to the guest, i.e. KVM will fail to actually migrate FP+SSE.

Because KVM_{G,S}ET_XSAVE are designed to allowing migrating between
hosts with and without XSAVE, KVM_GET_XSAVE on a non-XSAVE (by way of
fpu_copy_guest_fpstate_to_uabi()) always sets the FP+SSE bits in the
header so that KVM_SET_XSAVE will work even if the new host supports
XSAVE.

Fixes: ad856280 ("x86/kvm/fpu: Limit guest user_xfeatures to supported bits of XCR0")
bz: https://bugzilla.redhat.com/show_bug.cgi?id=2079311
Cc: stable@vger.kernel.org
Cc: Leonardo Bras <leobras@redhat.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
[sean: add comment, massage changelog]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20220824033057.3576315-3-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      a1020a25
    • Sean Christopherson's avatar
      KVM: x86: Reinstate kvm_vcpu_arch.guest_supported_xcr0 · ee519b3a
      Sean Christopherson authored 
      Reinstate the per-vCPU guest_supported_xcr0 by partially reverting
commit 988896bb; the implicit assessment that guest_supported_xcr0 is
always the same as guest_fpu.fpstate->user_xfeatures was incorrect.

kvm_vcpu_after_set_cpuid() isn't the only place that sets user_xfeatures,
as user_xfeatures is set to fpu_user_cfg.default_features when guest_fpu
is allocated via fpu_alloc_guest_fpstate() => __fpstate_reset().
guest_supported_xcr0 on the other hand is zero-allocated.  If userspace
never invokes KVM_SET_CPUID2, supported XCR0 will be '0', whereas the
allowed user XFEATURES will be non-zero.

Practically speaking, the edge case likely doesn't matter as no sane
userspace will live migrate a VM without ever doing KVM_SET_CPUID2. The
primary motivation is to prepare for KVM intentionally and explicitly
setting bits in user_xfeatures that are not set in guest_supported_xcr0.

Because KVM_{G,S}ET_XSAVE can be used to svae/restore FP+SSE state even
if the host doesn't support XSAVE, KVM needs to set the FP+SSE bits in
user_xfeatures even if they're not allowed in XCR0, e.g. because XCR0
isn't exposed to the guest.  At that point, the simplest fix is to track
the two things separately (allowed save/restore vs. allowed XCR0).

Fixes: 988896bb ("x86/kvm/fpu: Remove kvm_vcpu_arch.guest_supported_xcr0")
Cc: stable@vger.kernel.org
Cc: Leonardo Bras <leobras@redhat.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20220824033057.3576315-2-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      ee519b3a
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