Debian: DSA-2582-1: xen security update

    Date07 Dec 2012
    CategoryDebian
    35
    Posted ByLinuxSecurity Advisories
    Multiple denial of service vulnerabilities have been discovered in the xen hypervisor. One of the issue (CVE-2012-5513) could even lead to privilege escalation from guest to host.
    
    - -------------------------------------------------------------------------
    Debian Security Advisory DSA-2582-1                   This email address is being protected from spambots. You need JavaScript enabled to view it.
    http://www.debian.org/security/                         Yves-Alexis Perez
    December 07, 2012                      http://www.debian.org/security/faq
    - -------------------------------------------------------------------------
    
    Package        : xen
    Vulnerability  : several
    Problem type   : local
    Debian-specific: no
    CVE ID         : CVE-2011-3131 CVE-2012-4535 CVE-2012-4537 CVE-2012-4538 
                     CVE-2012-4539 CVE-2012-5510 CVE-2012-5513 CVE-2012-5514
                     CVE-2012-5515
    Debian Bug     : 
    
    Multiple denial of service vulnerabilities have been discovered in the xen
    hypervisor. One of the issue (CVE-2012-5513) could even lead to privilege
    escalation from guest to host.
    
    Some of the recently published Xen Security Advisories (XSA 25 and 28) are not
    fixed by this update and should be fixed in a future release.
    
    CVE-2011-3131 (XSA 5): DoS using I/OMMU faults from PCI-passthrough guest
    
    	A VM that controls a PCI[E] device directly can cause it to issue DMA
    	requests to invalid addresses. Although these requests are denied by the
    	I/OMMU, the hypervisor needs to handle the interrupt and clear the error from
    	the I/OMMU, and this can be used to live-lock a CPU and potentially hang the
    	host.
    
    CVE-2012-4535 (XSA 20): Timer overflow DoS vulnerability
    
    	A guest which sets a VCPU with an inappropriate deadline can cause an
    	infinite loop in Xen, blocking the affected physical CPU indefinitely.
    
    CVE-2012-4537 (XSA 22): Memory mapping failure DoS vulnerability
    
    	When set_p2m_entry fails, Xen's internal data structures (the p2m and m2p
    	tables) can get out of sync. This failure can be triggered by unusual guest
    	behaviour exhausting the memory reserved for the p2m table. If it happens,
    	subsequent guest-invoked memory operations can cause Xen to fail an assertion
    	and crash.
    
    CVE-2012-4538 (XSA 23): Unhooking empty PAE entries DoS vulnerability
    
    	The HVMOP_pagetable_dying hypercall does not correctly check the
    	caller's pagetable state, leading to a hypervisor crash.
    
    CVE-2012-4539 (XSA 24): Grant table hypercall infinite loop DoS vulnerability
    
    	Due to inappropriate duplicate use of the same loop control variable,
    	passing bad arguments to GNTTABOP_get_status_frames can cause an
    	infinite loop in the compat hypercall handler.
    
    CVE-2012-5510 (XSA 26): Grant table version switch list corruption vulnerability
    
    	Downgrading the grant table version of a guest involves freeing its status
    	pages. This freeing was incomplete - the page(s) are freed back to the
    	allocator, but not removed from the domain's tracking list. This would cause
    	list corruption, eventually leading to a hypervisor crash.
    
    CVE-2012-5513 (XSA 29): XENMEM_exchange may overwrite hypervisor memory
    
    	The handler for XENMEM_exchange accesses guest memory without range checking
    	the guest provided addresses, thus allowing these accesses to include the
    	hypervisor reserved range.
    	.
    	A malicious guest administrator can cause Xen to crash. If the out of address
    	space bounds access does not lead to a crash, a carefully crafted privilege
    	escalation cannot be excluded, even though the guest doesn't itself control
    	the values written.
    
    CVE-2012-5514 (XSA 30): Broken error handling in guest_physmap_mark_populate_on_demand()
    
    	guest_physmap_mark_populate_on_demand(), before carrying out its actual
    	operation, checks that the subject GFNs are not in use. If that check fails,
    	the code prints a message and bypasses the gfn_unlock() matching the
    	gfn_lock() carried out before entering the loop.
    	.
    	A malicious guest administrator can then use it to cause Xen to hang.
    
    CVE-2012-5515 (XSA 31): Several memory hypercall operations allow invalid extent order values
    
    	Allowing arbitrary extent_order input values for XENMEM_decrease_reservation,
    	XENMEM_populate_physmap, and XENMEM_exchange can cause arbitrarily long time
    	being spent in loops without allowing vital other code to get a chance to
    	execute. This may also cause inconsistent state resulting at the completion
    	of these hypercalls.
    
    For the stable distribution (squeeze), these problems have been fixed in
    version 4.0.1-5.5.
    
    For the testing distribution (wheezy), these problems have been fixed in
    version 4.1.3-6.
    
    For the unstable distribution (sid), these problems have been fixed in
    version 4.1.3-6.
    
    We recommend that you upgrade your xen packages.
    
    Further information about Debian Security Advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: http://www.debian.org/security/
    
    Mailing list: This email address is being protected from spambots. You need JavaScript enabled to view it.
    
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