linux_dsm_epyc7002/arch/x86
Paolo Bonzini 58c95070da KVM: x86: fix off-by-one in reserved bits check
29ecd66019 ("KVM: x86: avoid uninitialized variable warning",
2015-09-06) introduced a not-so-subtle problem, which probably
escaped review because it was not part of the patch context.

Before the patch, leaf was always equal to iterator.level.  After,
it is equal to iterator.level - 1 in the call to is_shadow_zero_bits_set,
and when is_shadow_zero_bits_set does another "-1" the check on
reserved bits becomes incorrect.  Using "iterator.level" in the call
fixes this call trace:

WARNING: CPU: 2 PID: 17000 at arch/x86/kvm/mmu.c:3385 handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]()
Modules linked in: tun sha256_ssse3 sha256_generic drbg binfmt_misc ipv6 vfat fat fuse dm_crypt dm_mod kvm_amd kvm crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd fam15h_power amd64_edac_mod k10temp edac_core amdkfd amd_iommu_v2 radeon acpi_cpufreq
[...]
Call Trace:
  dump_stack+0x4e/0x84
  warn_slowpath_common+0x95/0xe0
  warn_slowpath_null+0x1a/0x20
  handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]
  tdp_page_fault+0x231/0x290 [kvm]
  ? emulator_pio_in_out+0x6e/0xf0 [kvm]
  kvm_mmu_page_fault+0x36/0x240 [kvm]
  ? svm_set_cr0+0x95/0xc0 [kvm_amd]
  pf_interception+0xde/0x1d0 [kvm_amd]
  handle_exit+0x181/0xa70 [kvm_amd]
  ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm]
  kvm_arch_vcpu_ioctl_run+0x6f6/0x1730 [kvm]
  ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm]
  ? preempt_count_sub+0x9b/0xf0
  ? mutex_lock_killable_nested+0x26f/0x490
  ? preempt_count_sub+0x9b/0xf0
  kvm_vcpu_ioctl+0x358/0x710 [kvm]
  ? __fget+0x5/0x210
  ? __fget+0x101/0x210
  do_vfs_ioctl+0x2f4/0x560
  ? __fget_light+0x29/0x90
  SyS_ioctl+0x4c/0x90
  entry_SYSCALL_64_fastpath+0x16/0x73
---[ end trace 37901c8686d84de6 ]---

Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-25 10:31:29 +02:00
..
boot lib/decompressors: use real out buf size for gunzip with kernel 2015-09-10 13:29:01 -07:00
configs Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-09-04 15:49:32 -07:00
crypto crypto: ghash-clmulni: specify context size for ghash async algorithm 2015-09-04 23:21:07 +08:00
entry sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
ia32 x86/compat: Move copy_siginfo_*_user32() to signal_compat.c 2015-07-06 15:28:55 +02:00
include KVM: x86: trap AMD MSRs for the TSeg base and mask 2015-09-21 07:41:22 +02:00
kernel dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
kvm KVM: x86: fix off-by-one in reserved bits check 2015-09-25 10:31:29 +02:00
lguest Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 15:20:51 -07:00
lib x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer 2015-08-22 14:52:16 +02:00
math-emu Merge branch 'x86/urgent' into x86/asm to fix up conflicts and to pick up fixes 2015-08-18 09:39:47 +02:00
mm mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff() 2015-09-10 13:29:01 -07:00
net bpf: Make the bpf_prog_array_map more generic 2015-08-09 22:50:05 -07:00
oprofile x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()' 2015-03-23 11:14:17 +01:00
pci Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 14:33:35 -07:00
platform kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
power x86/ldt: Make modify_ldt synchronous 2015-07-31 10:23:23 +02:00
purgatory Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-10 12:35:46 -08:00
ras x86/ras: Move AMD MCE injector to arch/x86/ras/ 2015-08-13 10:12:54 +02:00
realmode Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-16 14:58:12 -08:00
tools x86, build: replace Perl script with Shell script 2015-01-26 13:37:18 -08:00
um x86/asm/tsc: Remove rdtsc_barrier() 2015-07-06 15:23:30 +02:00
video
xen xen: MFN/GFN/BFN terminology changes for 4.3-rc0 2015-09-10 16:21:11 -07:00
.gitignore x86/build: Add arch/x86/purgatory/ make generated files to gitignore 2014-10-09 09:29:46 +02:00
Kbuild x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/ 2015-06-03 18:51:37 +02:00
Kconfig kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
Kconfig.cpu
Kconfig.debug x86/entry/64, x86/nmi/64: Add CONFIG_DEBUG_ENTRY NMI testing code 2015-07-17 12:50:14 +02:00
Makefile Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 08:40:25 -07:00
Makefile_32.cpu
Makefile.um kbuild: use relative path more to include Makefile 2015-04-02 16:42:08 +02:00