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 <gustavoars@xxxxxxxxxx> > > 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/cover.1645513670.git.gustavoars@xxxxxxxxxx/ > > > --- > > 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
