Re: [kernel/isolation] c427534e48: BUG:kernel_NULL_pointer_dereference,address

[Peter Zijlstra]

On Sat, Jun 22, 2019 at 09:43:42AM +1000, Nicholas Piggin wrote:
> kernel test robot's on June 21, 2019 6:20 pm:

> > If you fix the issue, kindly add following tag
> > Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
> > 
> > 
> > [    0.562433] BUG: kernel NULL pointer dereference, address: 0000000000000000
> > [    0.562994] #PF: supervisor read access in kernel mode
> > [    0.562994] #PF: error_code(0x0000) - not-present page
> > [    0.562994] PGD 0 P4D 0 
> > [    0.562994] Oops: 0000 [#1] SMP PTI
> > [    0.562994] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5-00015-gc427534 #1
> > [    0.562994] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
> > [    0.562994] RIP: 0010:housekeeping_verify_smp+0x2b/0x41
> > [    0.562994] Code: 66 66 66 90 53 83 c8 ff 48 c7 c3 c0 e2 e3 84 48 89 de 89 c7 e8 94 d4 d7 fe 3b 05 22 77 b8 ff 73 13 89 c2 48 8b 0d db eb 28 00 <48> 0f a3 11 73 df 31 c0 5b c3 48 c7 c7 f0 0e 8d 84 e8 1b 84 3e fe
> > [    0.562994] RSP: 0000:ffffabda00327e18 EFLAGS: 00010293
> > [    0.562994] RAX: 0000000000000000 RBX: ffffffff84e3e2c0 RCX: 0000000000000000
> > [    0.562994] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84e3e2c0
> > [    0.562994] RBP: ffffffff852b7572 R08: 0000000000000044 R09: 0000000000000228
> > [    0.562994] R10: 0000000000000000 R11: ffff892f4f817e10 R12: ffffffff854a0938
> > [    0.562994] R13: 0000000000000002 R14: ffffffff852898d9 R15: 0000000000000000
> > [    0.562994] FS:  0000000000000000(0000) GS:ffff892fa1e00000(0000) knlGS:0000000000000000
> > [    0.562994] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [    0.562994] CR2: 0000000000000000 CR3: 000000001ec0a000 CR4: 00000000000406f0
> > [    0.562994] Call Trace:
> > [    0.562994]  do_one_initcall+0x46/0x214
> > [    0.562994]  kernel_init_freeable+0x1c7/0x272
> > [    0.562994]  ? rest_init+0xd0/0xd0
> > [    0.562994]  kernel_init+0xa/0x110
> > [    0.562994]  ret_from_fork+0x35/0x40
> > [    0.562994] Modules linked in:
> > [    0.562994] CR2: 0000000000000000
> > [    0.562994] ---[ end trace 1c0ad476e5b7f021 ]---
> 
> Oops, housekeeping_verify_smp needs to needs to check
> housekeeping_overidden before testing housekeeping_mask.
> 
> You want me to resend with a fix?

That'd be great.