KVM: X86: Fix dereference null cpufreq policy
Naresh Kamboju reported:
Linux version 5.6.0-rc4 (oe-user@oe-host) (gcc version
(GCC)) #1 SMP Sun Mar 1 22:59:08 UTC 2020
kvm: no hardware support
BUG: kernel NULL pointer dereference, address: 000000000000028c
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc4 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
04/01/2014
RIP: 0010:kobject_put+0x12/0x1c0
Call Trace:
cpufreq_cpu_put+0x15/0x20
kvm_arch_init+0x1f6/0x2b0
kvm_init+0x31/0x290
? svm_check_processor_compat+0xd/0xd
? svm_check_processor_compat+0xd/0xd
svm_init+0x21/0x23
do_one_initcall+0x61/0x2f0
? rdinit_setup+0x30/0x30
? rcu_read_lock_sched_held+0x4f/0x80
kernel_init_freeable+0x219/0x279
? rest_init+0x250/0x250
kernel_init+0xe/0x110
ret_from_fork+0x27/0x50
Modules linked in:
CR2: 000000000000028c
---[ end trace 239abf40c55c409b ]---
RIP: 0010:kobject_put+0x12/0x1c0
cpufreq policy which is get by cpufreq_cpu_get() can be NULL if it is failure,
this patch takes care of it.
Fixes: aaec7c03de (KVM: x86: avoid useless copy of cpufreq policy)
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed
