Hi. Please backport upstream commit b963a22e6d1a266a67e9eecc88134713fd54775c to 3.4. This patch has already been backported to other stable kernels.
The upstream patch does not clean apply to 3.4. The function kvm_apic_get_reg is apic_get_reg instead. Please backport similarly as commit 245d4b4480c20ffb50f0eddadcc6516b9017d863 from 3.2.54 by Ben Hutchings or commit 6f3bf648844e42246297315a389a7cb5a5d30ac2 from 3.5.7.28 by Luis Henriques. commit b963a22e6d1a266a67e9eecc88134713fd54775c Author: Andy Honig <[email protected]> Date: Tue Nov 19 14:12:18 2013 -0800 KVM: x86: Fix potential divide by 0 in lapic (CVE-2013-6367) Under guest controllable circumstances apic_get_tmcct will execute a divide by zero and cause a crash. If the guest cpuid support tsc deadline timers and performs the following sequence of requests the host will crash. - Set the mode to periodic - Set the TMICT to 0 - Set the mode bits to 11 (neither periodic, nor one shot, nor tsc deadline) - Set the TMICT to non-zero. Then the lapic_timer.period will be 0, but the TMICT will not be. If the guest then reads from the TMCCT then the host will perform a divide by 0. This patch ensures that if the lapic_timer.period is 0, then the division does not occur. Reported-by: Andrew Honig <[email protected]> Cc: [email protected] Signed-off-by: Andrew Honig <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Cheers, Vinson -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
