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| author | Zelin Deng <zelin.deng@linux.alibaba.com> | 2021-09-29 13:13:49 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-09-30 04:08:15 -0400 |
| commit | 773e89ab0056aaa2baa1ffd9f044551654410104 (patch) | |
| tree | 21f02e8fab3cd99d60b240830e0b7e2897ada3df | |
| parent | ad9af930680bb396c87582edc172b3a7cf2a3fbf (diff) | |
ptp: Fix ptp_kvm_getcrosststamp issue for x86 ptp_kvm
hv_clock is preallocated to have only HVC_BOOT_ARRAY_SIZE (64) elements;
if the PTP_SYS_OFFSET_PRECISE ioctl is executed on vCPUs whose index is
64 of higher, retrieving the struct pvclock_vcpu_time_info pointer with
"src = &hv_clock[cpu].pvti" will result in an out-of-bounds access and
a wild pointer. Change it to "this_cpu_pvti()" which is guaranteed to
be valid.
Fixes: 95a3d4454bb1 ("Switch kvmclock data to a PER_CPU variable")
Signed-off-by: Zelin Deng <zelin.deng@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Message-Id: <1632892429-101194-3-git-send-email-zelin.deng@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | drivers/ptp/ptp_kvm_x86.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/drivers/ptp/ptp_kvm_x86.c b/drivers/ptp/ptp_kvm_x86.c index 3dd519dfc473..d0096cd7096a 100644 --- a/drivers/ptp/ptp_kvm_x86.c +++ b/drivers/ptp/ptp_kvm_x86.c @@ -15,8 +15,6 @@ #include <linux/ptp_clock_kernel.h> #include <linux/ptp_kvm.h> -struct pvclock_vsyscall_time_info *hv_clock; - static phys_addr_t clock_pair_gpa; static struct kvm_clock_pairing clock_pair; @@ -28,8 +26,7 @@ int kvm_arch_ptp_init(void) return -ENODEV; clock_pair_gpa = slow_virt_to_phys(&clock_pair); - hv_clock = pvclock_get_pvti_cpu0_va(); - if (!hv_clock) + if (!pvclock_get_pvti_cpu0_va()) return -ENODEV; ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa, @@ -64,10 +61,8 @@ int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *tspec, struct pvclock_vcpu_time_info *src; unsigned int version; long ret; - int cpu; - cpu = smp_processor_id(); - src = &hv_clock[cpu].pvti; + src = this_cpu_pvti(); do { /* |