Commit d383b314 authored Oct 30, 2020 by Takashi Iwai Committed by Paolo Bonzini Oct 30, 2020

KVM: x86: Fix NULL dereference at kvm_msr_ignored_check()

The newly introduced kvm_msr_ignored_check() tries to print error or
debug messages via vcpu_*() macros, but those may cause Oops when NULL
vcpu is passed for KVM_GET_MSRS ioctl.

Fix it by replacing the print calls with kvm_*() macros.

(Note that this will leave vcpu argument completely unused in the
 function, but I didn't touch it to make the fix as small as
 possible.  A clean up may be applied later.)

Fixes: 12bc2132 ("KVM: X86: Do the same ignore_msrs check for feature msrs")
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1178280


Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Message-Id: <20201030151414.20165-1-tiwai@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 8a967d65

arch/x86/kvm/x86.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -265,12 +265,12 @@ static int kvm_msr_ignored_check(struct kvm_vcpu *vcpu, u32 msr,

		if (ignore_msrs) {
		if (report_ignored_msrs)
		vcpu_unimpl(vcpu, "ignored %s: 0x%x data 0x%llx\n",
		kvm_pr_unimpl("ignored %s: 0x%x data 0x%llx\n",
		op, msr, data);
		/* Mask the error */
		return 0;
		} else {
		vcpu_debug_ratelimited(vcpu, "unhandled %s: 0x%x data 0x%llx\n",
		kvm_debug_ratelimited("unhandled %s: 0x%x data 0x%llx\n",
		op, msr, data);
		return -ENOENT;
		}

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