linux-kernel - Re: [3.5.0 BUG] vmx_handle_exit: unexpected, valid vectoring info (0x80000b0e)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <505044AC.80205@redhat.com>
Date:	Wed, 12 Sep 2012 11:15:40 +0300
From:	Avi Kivity <avi@...hat.com>
To:	Fengguang Wu <fengguang.wu@...el.com>
CC:	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>
Subject: Re: [3.5.0 BUG] vmx_handle_exit: unexpected, valid vectoring info
 (0x80000b0e)

On 09/12/2012 07:40 AM, Fengguang Wu wrote:
> Hi,
> 
> 3 of my test boxes running v3.5 kernel become unaccessible and I find
> two of them kept emitting this dmesg:
> 
> vmx_handle_exit: unexpected, valid vectoring info (0x80000b0e) and exit reason is 0x31
> 
> The other one has froze and the above lines are the last dmesg.
> Any ideas?

First, that printk should be rate-limited.

Second, we should add EXIT_REASON_EPT_MISCONFIG (0x31) to 

	if ((vectoring_info & VECTORING_INFO_VALID_MASK) &&
			(exit_reason != EXIT_REASON_EXCEPTION_NMI &&
			exit_reason != EXIT_REASON_EPT_VIOLATION &&
			exit_reason != EXIT_REASON_TASK_SWITCH))
		printk(KERN_WARNING "%s: unexpected, valid vectoring info "
		       "(0x%x) and exit reason is 0x%x\n",
		       __func__, vectoring_info, exit_reason);

since it's easily caused by the guest.

Third, it's really unexpected.  It seems the guest was attempting to deliver a page fault exception (0x0e) but encountered an mmio page during delivery (in the IDT, TSS, stack, or page tables).  Is this reproducible?  If so it's easy to patch kvm to halt in that case and allow examining the guest via qemu.

Maybe we should do so regardless (return a KVM_EXIT_INTERNAL_ERROR).


-- 
error compiling committee.c: too many arguments to function
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/