Replace one-element array with a flexible-array member in struct
MR_DRV_RAID_MAP and use the flex_array_size() helper.
This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().
Link: https://en.wikipedia.org/wiki/Flexible_array_member
Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
Changes in v2:
- None.
drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
index da1cad1ee123..9cb36ef96c2c 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fp.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
@@ -229,8 +229,8 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
le32_to_cpu(desc_table->raid_map_desc_offset));
memcpy(pDrvRaidMap->ldSpanMap,
fw_map_dyn->ld_span_map,
- sizeof(struct MR_LD_SPAN_MAP) *
- le32_to_cpu(desc_table->raid_map_desc_elements));
+ flex_array_size(pDrvRaidMap, ldSpanMap,
+ le32_to_cpu(desc_table->raid_map_desc_elements)));
break;
default:
dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
@@ -254,7 +254,7 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
pDrvRaidMap->ldTgtIdToLd[i] =
(u16)fw_map_ext->ldTgtIdToLd[i];
memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
- sizeof(struct MR_LD_SPAN_MAP) * ld_count);
+ flex_array_size(pDrvRaidMap, ldSpanMap, ld_count));
memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
index 9adb8b30f422..5fe2f7a6eebe 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
@@ -1182,7 +1182,7 @@ struct MR_DRV_RAID_MAP {
devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES_DYN];
u16 ldTgtIdToLd[MAX_LOGICAL_DRIVES_DYN];
struct MR_ARRAY_INFO arMapInfo[MAX_API_ARRAYS_DYN];
- struct MR_LD_SPAN_MAP ldSpanMap[1];
+ struct MR_LD_SPAN_MAP ldSpanMap[];
};
--
2.27.0
On Wed, Aug 04, 2021 at 11:20:04PM -0500, Gustavo A. R. Silva wrote:
> Replace one-element array with a flexible-array member in struct
> MR_DRV_RAID_MAP and use the flex_array_size() helper.
>
> This helps with the ongoing efforts to globally enable -Warray-bounds
> and get us closer to being able to tighten the FORTIFY_SOURCE routines
> on memcpy().
>
> Link: https://en.wikipedia.org/wiki/Flexible_array_member
> Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://github.com/KSPP/linux/issues/109
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
I'd really like to see this fixed. :) I'm running into this 1-element
array problem now with UBSAN_BOUNDS:
[ 10.011173] UBSAN: array-index-out-of-bounds in /build/linux-WLUive/linux-5.15.0/drivers/scsi/megaraid/megaraid_sas_fp.c:103:32
[ 10.087824] index 1 is out of range for type 'MR_LD_SPAN_MAP [1]'
and I'm not the only one:
https://bugzilla.kernel.org/show_bug.cgi?id=215943
> ---
> Changes in v2:
> - None.
>
> drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
> drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
> index da1cad1ee123..9cb36ef96c2c 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fp.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
> @@ -229,8 +229,8 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> le32_to_cpu(desc_table->raid_map_desc_offset));
> memcpy(pDrvRaidMap->ldSpanMap,
> fw_map_dyn->ld_span_map,
> - sizeof(struct MR_LD_SPAN_MAP) *
> - le32_to_cpu(desc_table->raid_map_desc_elements));
> + flex_array_size(pDrvRaidMap, ldSpanMap,
> + le32_to_cpu(desc_table->raid_map_desc_elements)));
> break;
> default:
> dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
> @@ -254,7 +254,7 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> pDrvRaidMap->ldTgtIdToLd[i] =
> (u16)fw_map_ext->ldTgtIdToLd[i];
> memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
> - sizeof(struct MR_LD_SPAN_MAP) * ld_count);
> + flex_array_size(pDrvRaidMap, ldSpanMap, ld_count));
> memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
> sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
> memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> index 9adb8b30f422..5fe2f7a6eebe 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> @@ -1182,7 +1182,7 @@ struct MR_DRV_RAID_MAP {
> devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES_DYN];
> u16 ldTgtIdToLd[MAX_LOGICAL_DRIVES_DYN];
> struct MR_ARRAY_INFO arMapInfo[MAX_API_ARRAYS_DYN];
> - struct MR_LD_SPAN_MAP ldSpanMap[1];
> + struct MR_LD_SPAN_MAP ldSpanMap[];
>
> };
>
I think this patch is incomplete, and the wrapping struct needs to be
adjusted too:
@@ -1193,7 +1193,7 @@ struct MR_DRV_RAID_MAP {
struct MR_DRV_RAID_MAP_ALL {
struct MR_DRV_RAID_MAP raidMap;
- struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN - 1];
+ struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN];
} __packed;
With that added, I get zero changes to the executable code.
I assume the others need adjustment too.
--
Kees Cook
On Wed, Jun 22, 2022 at 03:26:38PM -0700, Kees Cook wrote:
> On Wed, Aug 04, 2021 at 11:20:04PM -0500, Gustavo A. R. Silva wrote:
> > Replace one-element array with a flexible-array member in struct
> > MR_DRV_RAID_MAP and use the flex_array_size() helper.
> >
> > This helps with the ongoing efforts to globally enable -Warray-bounds
> > and get us closer to being able to tighten the FORTIFY_SOURCE routines
> > on memcpy().
> >
> > Link: https://en.wikipedia.org/wiki/Flexible_array_member
> > Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> > Link: https://github.com/KSPP/linux/issues/79
> > Link: https://github.com/KSPP/linux/issues/109
> > Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> I'd really like to see this fixed. :) I'm running into this 1-element
> array problem now with UBSAN_BOUNDS:
Wow; another forgoten patch from the times we didn't have Patchwork. :)
>
> [ 10.011173] UBSAN: array-index-out-of-bounds in /build/linux-WLUive/linux-5.15.0/drivers/scsi/megaraid/megaraid_sas_fp.c:103:32
> [ 10.087824] index 1 is out of range for type 'MR_LD_SPAN_MAP [1]'
>
> and I'm not the only one:
>
> https://bugzilla.kernel.org/show_bug.cgi?id=215943
It's actually great that other people are running into these issues now.
That could only means that we should fixed ASAP. :)
We also have this other series that hasn't been applied yet:
https://lore.kernel.org/linux-hardening/[email protected]/
>
> > ---
> > Changes in v2:
> > - None.
> >
> > drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
> > drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
> > 2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > index da1cad1ee123..9cb36ef96c2c 100644
> > --- a/drivers/scsi/megaraid/megaraid_sas_fp.c
> > +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > @@ -229,8 +229,8 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > le32_to_cpu(desc_table->raid_map_desc_offset));
> > memcpy(pDrvRaidMap->ldSpanMap,
> > fw_map_dyn->ld_span_map,
> > - sizeof(struct MR_LD_SPAN_MAP) *
> > - le32_to_cpu(desc_table->raid_map_desc_elements));
> > + flex_array_size(pDrvRaidMap, ldSpanMap,
> > + le32_to_cpu(desc_table->raid_map_desc_elements)));
> > break;
> > default:
> > dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
> > @@ -254,7 +254,7 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > pDrvRaidMap->ldTgtIdToLd[i] =
> > (u16)fw_map_ext->ldTgtIdToLd[i];
> > memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
> > - sizeof(struct MR_LD_SPAN_MAP) * ld_count);
> > + flex_array_size(pDrvRaidMap, ldSpanMap, ld_count));
> > memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
> > sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
> > memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
> > diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > index 9adb8b30f422..5fe2f7a6eebe 100644
> > --- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > @@ -1182,7 +1182,7 @@ struct MR_DRV_RAID_MAP {
> > devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES_DYN];
> > u16 ldTgtIdToLd[MAX_LOGICAL_DRIVES_DYN];
> > struct MR_ARRAY_INFO arMapInfo[MAX_API_ARRAYS_DYN];
> > - struct MR_LD_SPAN_MAP ldSpanMap[1];
> > + struct MR_LD_SPAN_MAP ldSpanMap[];
> >
> > };
> >
>
> I think this patch is incomplete, and the wrapping struct needs to be
> adjusted too:
>
> @@ -1193,7 +1193,7 @@ struct MR_DRV_RAID_MAP {
> struct MR_DRV_RAID_MAP_ALL {
>
> struct MR_DRV_RAID_MAP raidMap;
> - struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN - 1];
> + struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN];
> } __packed;
>
> With that added, I get zero changes to the executable code.
>
> I assume the others need adjustment too.
Interesting... OK, let me refresh my memory about the whole thing
and be back in a minute.
--
Gustavo
On Thu, Jun 23, 2022 at 03:45:33AM +0200, Gustavo A. R. Silva wrote:
> On Wed, Jun 22, 2022 at 03:26:38PM -0700, Kees Cook wrote:
> > On Wed, Aug 04, 2021 at 11:20:04PM -0500, Gustavo A. R. Silva wrote:
> > > Replace one-element array with a flexible-array member in struct
> > > MR_DRV_RAID_MAP and use the flex_array_size() helper.
> > >
> > > This helps with the ongoing efforts to globally enable -Warray-bounds
> > > and get us closer to being able to tighten the FORTIFY_SOURCE routines
> > > on memcpy().
> > >
> > > Link: https://en.wikipedia.org/wiki/Flexible_array_member
> > > Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> > > Link: https://github.com/KSPP/linux/issues/79
> > > Link: https://github.com/KSPP/linux/issues/109
> > > Signed-off-by: Gustavo A. R. Silva <[email protected]>
> >
> > I'd really like to see this fixed. :) I'm running into this 1-element
> > array problem now with UBSAN_BOUNDS:
>
> Wow; another forgoten patch from the times we didn't have Patchwork. :)
>
> >
> > [ 10.011173] UBSAN: array-index-out-of-bounds in /build/linux-WLUive/linux-5.15.0/drivers/scsi/megaraid/megaraid_sas_fp.c:103:32
> > [ 10.087824] index 1 is out of range for type 'MR_LD_SPAN_MAP [1]'
> >
> > and I'm not the only one:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=215943
>
> It's actually great that other people are running into these issues now.
> That could only means that we should fixed ASAP. :)
>
> We also have this other series that hasn't been applied yet:
>
> https://lore.kernel.org/linux-hardening/[email protected]/
>
> >
> > > ---
> > > Changes in v2:
> > > - None.
> > >
> > > drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
> > > drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
> > > 2 files changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > index da1cad1ee123..9cb36ef96c2c 100644
> > > --- a/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > @@ -229,8 +229,8 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > > le32_to_cpu(desc_table->raid_map_desc_offset));
> > > memcpy(pDrvRaidMap->ldSpanMap,
> > > fw_map_dyn->ld_span_map,
> > > - sizeof(struct MR_LD_SPAN_MAP) *
> > > - le32_to_cpu(desc_table->raid_map_desc_elements));
> > > + flex_array_size(pDrvRaidMap, ldSpanMap,
> > > + le32_to_cpu(desc_table->raid_map_desc_elements)));
> > > break;
> > > default:
> > > dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
> > > @@ -254,7 +254,7 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > > pDrvRaidMap->ldTgtIdToLd[i] =
> > > (u16)fw_map_ext->ldTgtIdToLd[i];
> > > memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
> > > - sizeof(struct MR_LD_SPAN_MAP) * ld_count);
> > > + flex_array_size(pDrvRaidMap, ldSpanMap, ld_count));
> > > memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
> > > sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
> > > memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
> > > diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > index 9adb8b30f422..5fe2f7a6eebe 100644
> > > --- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > @@ -1182,7 +1182,7 @@ struct MR_DRV_RAID_MAP {
> > > devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES_DYN];
> > > u16 ldTgtIdToLd[MAX_LOGICAL_DRIVES_DYN];
> > > struct MR_ARRAY_INFO arMapInfo[MAX_API_ARRAYS_DYN];
> > > - struct MR_LD_SPAN_MAP ldSpanMap[1];
> > > + struct MR_LD_SPAN_MAP ldSpanMap[];
> > >
> > > };
> > >
> >
> > I think this patch is incomplete, and the wrapping struct needs to be
> > adjusted too:
> >
> > @@ -1193,7 +1193,7 @@ struct MR_DRV_RAID_MAP {
> > struct MR_DRV_RAID_MAP_ALL {
> >
> > struct MR_DRV_RAID_MAP raidMap;
> > - struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN - 1];
> > + struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN];
> > } __packed;
BTW, I'd really like to get some input from the maintainers of this
code. :)
Thanks
--
Gustavo
> >
> > With that added, I get zero changes to the executable code.
> >
> > I assume the others need adjustment too.
>
> Interesting... OK, let me refresh my memory about the whole thing
> and be back in a minute.
>
> --
> Gustavo
On Thu, Jun 23, 2022 at 05:14:01AM +0200, Gustavo A. R. Silva wrote:
> On Thu, Jun 23, 2022 at 03:45:33AM +0200, Gustavo A. R. Silva wrote:
> > On Wed, Jun 22, 2022 at 03:26:38PM -0700, Kees Cook wrote:
> > > On Wed, Aug 04, 2021 at 11:20:04PM -0500, Gustavo A. R. Silva wrote:
> > > > Replace one-element array with a flexible-array member in struct
> > > > MR_DRV_RAID_MAP and use the flex_array_size() helper.
> > > >
> > > > This helps with the ongoing efforts to globally enable -Warray-bounds
> > > > and get us closer to being able to tighten the FORTIFY_SOURCE routines
> > > > on memcpy().
> > > >
> > > > Link: https://en.wikipedia.org/wiki/Flexible_array_member
> > > > Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> > > > Link: https://github.com/KSPP/linux/issues/79
> > > > Link: https://github.com/KSPP/linux/issues/109
> > > > Signed-off-by: Gustavo A. R. Silva <[email protected]>
> > >
> > > I'd really like to see this fixed. :) I'm running into this 1-element
> > > array problem now with UBSAN_BOUNDS:
> >
> > Wow; another forgoten patch from the times we didn't have Patchwork. :)
> >
> > >
> > > [ 10.011173] UBSAN: array-index-out-of-bounds in /build/linux-WLUive/linux-5.15.0/drivers/scsi/megaraid/megaraid_sas_fp.c:103:32
> > > [ 10.087824] index 1 is out of range for type 'MR_LD_SPAN_MAP [1]'
> > >
> > > and I'm not the only one:
> > >
> > > https://bugzilla.kernel.org/show_bug.cgi?id=215943
> >
> > It's actually great that other people are running into these issues now.
> > That could only means that we should fixed ASAP. :)
> >
> > We also have this other series that hasn't been applied yet:
> >
> > https://lore.kernel.org/linux-hardening/[email protected]/
> >
> > >
> > > > ---
> > > > Changes in v2:
> > > > - None.
> > > >
> > > > drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
> > > > drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
> > > > 2 files changed, 4 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > > index da1cad1ee123..9cb36ef96c2c 100644
> > > > --- a/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > > +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > > @@ -229,8 +229,8 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > > > le32_to_cpu(desc_table->raid_map_desc_offset));
> > > > memcpy(pDrvRaidMap->ldSpanMap,
> > > > fw_map_dyn->ld_span_map,
> > > > - sizeof(struct MR_LD_SPAN_MAP) *
> > > > - le32_to_cpu(desc_table->raid_map_desc_elements));
> > > > + flex_array_size(pDrvRaidMap, ldSpanMap,
> > > > + le32_to_cpu(desc_table->raid_map_desc_elements)));
> > > > break;
> > > > default:
> > > > dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
> > > > @@ -254,7 +254,7 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > > > pDrvRaidMap->ldTgtIdToLd[i] =
> > > > (u16)fw_map_ext->ldTgtIdToLd[i];
> > > > memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
> > > > - sizeof(struct MR_LD_SPAN_MAP) * ld_count);
> > > > + flex_array_size(pDrvRaidMap, ldSpanMap, ld_count));
> > > > memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
> > > > sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
> > > > memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
> > > > diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > > index 9adb8b30f422..5fe2f7a6eebe 100644
> > > > --- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > > +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > > @@ -1182,7 +1182,7 @@ struct MR_DRV_RAID_MAP {
> > > > devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES_DYN];
> > > > u16 ldTgtIdToLd[MAX_LOGICAL_DRIVES_DYN];
> > > > struct MR_ARRAY_INFO arMapInfo[MAX_API_ARRAYS_DYN];
> > > > - struct MR_LD_SPAN_MAP ldSpanMap[1];
> > > > + struct MR_LD_SPAN_MAP ldSpanMap[];
> > > >
> > > > };
> > > >
> > >
> > > I think this patch is incomplete, and the wrapping struct needs to be
> > > adjusted too:
> > >
> > > @@ -1193,7 +1193,7 @@ struct MR_DRV_RAID_MAP {
> > > struct MR_DRV_RAID_MAP_ALL {
> > >
> > > struct MR_DRV_RAID_MAP raidMap;
> > > - struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN - 1];
> > > + struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN];
> > > } __packed;
>
> BTW, I'd really like to get some input from the maintainers of this
> code. :)
Agreed, though if we get 0 output from a diffoscope of the object files,
I think it's safe to carry such patches in our trees. This is how I've
been testing:
$ make allmodconfig
$ ./scripts/config -d GCOV_KERNEL -d KCOV -d GCC_PLUGINS -d IKHEADERS -d KASAN -d UBSAN
$ make olddefconfig
$ make the/path/to/code.o
$ cp the/path/to/code.o the/path/to/code.before
$ *apply patch*
$ make the/path/to/code.o
$ cp the/path/to/code.o the/path/to/code.after
$ diffoscope the/path/to/code.before the/path/to/code.after
--
Kees Cook
On Thu, Jun 23, 2022 at 08:19:49AM -0700, Kees Cook wrote:
> On Thu, Jun 23, 2022 at 05:14:01AM +0200, Gustavo A. R. Silva wrote:
> > On Thu, Jun 23, 2022 at 03:45:33AM +0200, Gustavo A. R. Silva wrote:
> > > On Wed, Jun 22, 2022 at 03:26:38PM -0700, Kees Cook wrote:
> > > > On Wed, Aug 04, 2021 at 11:20:04PM -0500, Gustavo A. R. Silva wrote:
> > > > > Replace one-element array with a flexible-array member in struct
> > > > > MR_DRV_RAID_MAP and use the flex_array_size() helper.
> > > > >
> > > > > This helps with the ongoing efforts to globally enable -Warray-bounds
> > > > > and get us closer to being able to tighten the FORTIFY_SOURCE routines
> > > > > on memcpy().
> > > > >
> > > > > Link: https://en.wikipedia.org/wiki/Flexible_array_member
> > > > > Link: https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> > > > > Link: https://github.com/KSPP/linux/issues/79
> > > > > Link: https://github.com/KSPP/linux/issues/109
> > > > > Signed-off-by: Gustavo A. R. Silva <[email protected]>
> > > >
> > > > I'd really like to see this fixed. :) I'm running into this 1-element
> > > > array problem now with UBSAN_BOUNDS:
> > >
> > > Wow; another forgoten patch from the times we didn't have Patchwork. :)
> > >
> > > >
> > > > [ 10.011173] UBSAN: array-index-out-of-bounds in /build/linux-WLUive/linux-5.15.0/drivers/scsi/megaraid/megaraid_sas_fp.c:103:32
> > > > [ 10.087824] index 1 is out of range for type 'MR_LD_SPAN_MAP [1]'
> > > >
> > > > and I'm not the only one:
> > > >
> > > > https://bugzilla.kernel.org/show_bug.cgi?id=215943
> > >
> > > It's actually great that other people are running into these issues now.
> > > That could only means that we should fixed ASAP. :)
> > >
> > > We also have this other series that hasn't been applied yet:
> > >
> > > https://lore.kernel.org/linux-hardening/[email protected]/
> > >
> > > >
> > > > > ---
> > > > > Changes in v2:
> > > > > - None.
> > > > >
> > > > > drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
> > > > > drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +-
> > > > > 2 files changed, 4 insertions(+), 4 deletions(-)
> > > > >
> > > > > diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > > > index da1cad1ee123..9cb36ef96c2c 100644
> > > > > --- a/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > > > +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
> > > > > @@ -229,8 +229,8 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > > > > le32_to_cpu(desc_table->raid_map_desc_offset));
> > > > > memcpy(pDrvRaidMap->ldSpanMap,
> > > > > fw_map_dyn->ld_span_map,
> > > > > - sizeof(struct MR_LD_SPAN_MAP) *
> > > > > - le32_to_cpu(desc_table->raid_map_desc_elements));
> > > > > + flex_array_size(pDrvRaidMap, ldSpanMap,
> > > > > + le32_to_cpu(desc_table->raid_map_desc_elements)));
> > > > > break;
> > > > > default:
> > > > > dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
> > > > > @@ -254,7 +254,7 @@ static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
> > > > > pDrvRaidMap->ldTgtIdToLd[i] =
> > > > > (u16)fw_map_ext->ldTgtIdToLd[i];
> > > > > memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
> > > > > - sizeof(struct MR_LD_SPAN_MAP) * ld_count);
> > > > > + flex_array_size(pDrvRaidMap, ldSpanMap, ld_count));
> > > > > memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
> > > > > sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
> > > > > memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
> > > > > diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > > > index 9adb8b30f422..5fe2f7a6eebe 100644
> > > > > --- a/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > > > +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h
> > > > > @@ -1182,7 +1182,7 @@ struct MR_DRV_RAID_MAP {
> > > > > devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES_DYN];
> > > > > u16 ldTgtIdToLd[MAX_LOGICAL_DRIVES_DYN];
> > > > > struct MR_ARRAY_INFO arMapInfo[MAX_API_ARRAYS_DYN];
> > > > > - struct MR_LD_SPAN_MAP ldSpanMap[1];
> > > > > + struct MR_LD_SPAN_MAP ldSpanMap[];
> > > > >
> > > > > };
> > > > >
> > > >
> > > > I think this patch is incomplete, and the wrapping struct needs to be
> > > > adjusted too:
> > > >
> > > > @@ -1193,7 +1193,7 @@ struct MR_DRV_RAID_MAP {
> > > > struct MR_DRV_RAID_MAP_ALL {
> > > >
> > > > struct MR_DRV_RAID_MAP raidMap;
> > > > - struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN - 1];
> > > > + struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN];
> > > > } __packed;
> >
> > BTW, I'd really like to get some input from the maintainers of this
> > code. :)
>
> Agreed, though if we get 0 output from a diffoscope of the object files,
> I think it's safe to carry such patches in our trees. This is how I've
> been testing:
Which object files are you comparing here? because I don't see the zero
change when comparing the before and after of megaraid_sas_fp.o with
the change you propose.
>
> $ make allmodconfig
> $ ./scripts/config -d GCOV_KERNEL -d KCOV -d GCC_PLUGINS -d IKHEADERS -d KASAN -d UBSAN
> $ make olddefconfig
> $ make the/path/to/code.o
> $ cp the/path/to/code.o the/path/to/code.before
> $ *apply patch*
> $ make the/path/to/code.o
> $ cp the/path/to/code.o the/path/to/code.after
> $ diffoscope the/path/to/code.before the/path/to/code.after
Yep; that's how we do it. However, I think the zero change is the
exception, not the norm in these sorts of changes.
The machine code could easily change after refactoring the code a
bit as a consequence of the flex-array transformation. It's not like
we are merely removing the 1 from the array declaration. We are also
making use of helpers like struct_size(), flex_array_size() and in
some cases we are making the code to stop allocating some too-many
extra bytes (which usually account for the size of one item of the
trailing array) that are never actually used. I think that could
easily impact how the compiler ultimately arrange the code.
--
Gustavo
On Thu, Jun 23, 2022 at 05:38:25PM +0200, Gustavo A. R. Silva wrote:
> Which object files are you comparing here? because I don't see the zero
> change when comparing the before and after of megaraid_sas_fp.o with
> the change you propose.
Hm, maybe I did something wrong. But I was looking at megaraid_sas_fp.o
--
Kees Cook
On Fri, Jun 24, 2022 at 10:48:39AM -0700, Kees Cook wrote:
> On Thu, Jun 23, 2022 at 05:38:25PM +0200, Gustavo A. R. Silva wrote:
> > Which object files are you comparing here? because I don't see the zero
> > change when comparing the before and after of megaraid_sas_fp.o with
> > the change you propose.
>
> Hm, maybe I did something wrong. But I was looking at megaraid_sas_fp.o
Explaining my process got a bit long, so I wrote a blog post on it.
Here's how I did my examination of the resulting output:
https://outflux.net/blog/archives/2022/06/24/finding-binary-differences/
--
Kees Cook
>
> BTW, I'd really like to get some input from the maintainers of this
> code. :)
Original patch along with the below change looks good.
@@ -1193,7 +1193,7 @@ struct MR_DRV_RAID_MAP {
struct MR_DRV_RAID_MAP_ALL {
struct MR_DRV_RAID_MAP raidMap;
- struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN - 1];
+ struct MR_LD_SPAN_MAP ldSpanMap[MAX_LOGICAL_DRIVES_DYN];
} __packed;
I will test it and then can provide an Acked-by/Tested-by tag.
Thanks,
Sumit