nvdimm crash at boot
From: Kees Cook
Date: Tue Jan 08 2019 - 18:10:30 EST
This is a warn that I added to fail more gracefully (sorry for
whitespace damage):
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 4890310df874..1161b994b1ec 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -516,6 +516,8 @@ static umode_t nvdimm_visible(struct kobject
*kobj, struct attribute *a, int n)
return a->mode;
if (nvdimm->sec.state < 0)
return 0;
+ if (WARN_ON_ONCE(!nvdimm->sec.ops))
+ return 0;
/* Are there any state mutation ops? */
if (nvdimm->sec.ops->freeze || nvdimm->sec.ops->disable
|| nvdimm->sec.ops->change_key
Without it, I would crash at boot due to the sec.ops dereference. It's
not clear to me if there is a better solution than just the sec.ops
NULL test (i.e. should it ever be NULL?)
[ 1.393599] WARNING: CPU: 3 PID: 484 at
drivers/nvdimm/dimm_devs.c:519 nvdimm_visible+0x79/0x80
[ 1.393858] Modules linked in:
[ 1.393858] CPU: 3 PID: 484 Comm: kworker/u8:3 Not tainted 5.0.0-rc1+ #926
[ 1.393858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.10.2-1ubuntu1 04/01/2014
[ 1.396781] Workqueue: events_unbound async_run_entry_fn
[ 1.396781] RIP: 0010:nvdimm_visible+0x79/0x80
[ 1.396781] Code: e8 4c fc ff ff eb c7 48 83 78 20 00 75 e6 48 83
78 10 00 75 df 48 83 78 28 00 75 d8 48 83 78 30 00 75 d1 b8 24 01 00
00 eb b1 <0f> 0b eb ad 0f 1f 00 0f 1f 44 00 00 55 48 89 e5 41 57 41 56
41 55
[ 1.396781] RSP: 0000:ffffb911803abd00 EFLAGS: 00010246
[ 1.396781] RAX: 0000000000000000 RBX: ffffffff98cf5a80 RCX: 00000000000001a4
[ 1.396781] RDX: 0000000000000004 RSI: ffffffff98cf5a80 RDI: ffff94e7ed088028
[ 1.396781] RBP: ffffb911803abd10 R08: 0000000000000000 R09: 0000000000000001
[ 1.396781] R10: ffffb911803abaf8 R11: 0000000000000000 R12: ffff94e7ed088028
[ 1.396781] R13: ffff94e7ed088028 R14: ffffffff98cf5a60 R15: 0000000000000000
[ 1.396781] FS: 0000000000000000(0000) GS:ffff94e7efb80000(0000)
knlGS:0000000000000000
[ 1.396781] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.396781] CR2: 00000000ffffffff CR3: 0000000150822001 CR4: 00000000001606e0
[ 1.396781] Call Trace:
[ 1.396781] internal_create_group+0xf4/0x380
[ 1.396781] sysfs_create_groups+0x46/0xb0
[ 1.396781] device_add+0x331/0x680
[ 1.396781] nd_async_device_register+0x15/0x60
[ 1.396781] async_run_entry_fn+0x38/0x100
[ 1.396781] process_one_work+0x22b/0x5a0
[ 1.396781] worker_thread+0x3f/0x3b0
[ 1.396781] kthread+0x12b/0x150
[ 1.396781] ? process_one_work+0x5a0/0x5a0
[ 1.396781] ? kthread_park+0xa0/0xa0
[ 1.396781] ret_from_fork+0x24/0x30
[ 1.396781] irq event stamp: 952
[ 1.396781] hardirqs last enabled at (951): [<ffffffff973f5cb4>]
__slab_alloc.constprop.79+0x44/0x70
[ 1.396781] hardirqs last disabled at (952): [<ffffffff97201cf0>]
trace_hardirqs_off_thunk+0x1a/0x1c
[ 1.396781] softirqs last enabled at (0): [<ffffffff97267ae3>]
copy_process.part.55+0x413/0x1f10
[ 1.396781] softirqs last disabled at (0): [<0000000000000000>]
(null)
[ 1.396781] ---[ end trace 5608ce056f09564f ]---
I assume this crash is due to be using nvdimm without any special
markings (i.e. I'm using it crudely with pstore), in KVM:
RAM_SIZE=16384
NVDIMM_SIZE=128
MAX_SIZE=$(( RAM_SIZE + NVDIMM_SIZE ))
sudo qemu-system-x86_64 \
...
-machine pc,nvdimm \
-m ${RAM_SIZE}M,slots=2,maxmem=${MAX_SIZE}M \
-object
memory-backend-file,id=mem1,share=on,mem-path=nvdimm.img,size=${NVDIMM_SIZE}M,align=128M
\
-device nvdimm,id=nvdimm1,memdev=mem1 \
...
-append '... ramoops.mem_size=1048576 ramoops.ecc=1
ramoops.mem_address=0x440000000 ramoops.console_size=16384
ramoops.ftrace_size=16384 ramoops.pmsg_size=16384
ramoops.record_size=32768'
I assume 37833fb7989a9 ("acpi/nfit, libnvdimm: Add freeze security
support to Intel nvdimm") was where it started, but I didn't actually
bisect.
--
Kees Cook