On Mon, 2 Mar 2020 at 12:48, Wanpeng Li <kernellwp@xxxxxxxxx> wrote: > > From: Wanpeng Li <wanpengli@xxxxxxxxxxx> > > 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@xxxxxxxxxx> > Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> > Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> Tested-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Applied this patch and test boot pass. - Naresh
