There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code according to the use of a flexible-array member in struct MR_FW_RAID_MAP instead of one-element array, and use the struct_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(). [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] 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> --- Changes in v2: - Revert changes in struct MR_FW_RAID_MAP_ALL. - Update Subject line and changelog text. drivers/scsi/megaraid/megaraid_sas_base.c | 6 +++--- drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++--- drivers/scsi/megaraid/megaraid_sas_fusion.h | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index ec10b2497310..d072f9caeb4a 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -5147,9 +5147,9 @@ static void megasas_update_ext_vd_details(struct megasas_instance *instance) fusion->current_map_sz = ventura_map_sz; fusion->max_map_sz = ventura_map_sz; } else { - fusion->old_map_sz = sizeof(struct MR_FW_RAID_MAP) + - (sizeof(struct MR_LD_SPAN_MAP) * - (instance->fw_supported_vd_count - 1)); + fusion->old_map_sz = + struct_size((struct MR_FW_RAID_MAP *)0, ldSpanMap, + instance->fw_supported_vd_count); fusion->new_map_sz = sizeof(struct MR_FW_RAID_MAP_EXT); fusion->max_map_sz = diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c index 83f69c33b01a..da1cad1ee123 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fp.c +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c @@ -326,9 +326,9 @@ u8 MR_ValidateMapInfo(struct megasas_instance *instance, u64 map_id) else if (instance->supportmax256vd) expected_size = sizeof(struct MR_FW_RAID_MAP_EXT); else - expected_size = - (sizeof(struct MR_FW_RAID_MAP) - sizeof(struct MR_LD_SPAN_MAP) + - (sizeof(struct MR_LD_SPAN_MAP) * le16_to_cpu(pDrvRaidMap->ldCount))); + expected_size = struct_size((struct MR_FW_RAID_MAP *)0, + ldSpanMap, + le16_to_cpu(pDrvRaidMap->ldCount)); if (le32_to_cpu(pDrvRaidMap->totalSize) != expected_size) { dev_dbg(&instance->pdev->dev, "megasas: map info structure size 0x%x", diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.h b/drivers/scsi/megaraid/megaraid_sas_fusion.h index ce84f811e5e1..a47139ef9ee2 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fusion.h +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.h @@ -942,7 +942,7 @@ struct MR_FW_RAID_MAP { u8 reserved2[7]; struct MR_ARRAY_INFO arMapInfo[MAX_RAIDMAP_ARRAYS]; struct MR_DEV_HANDLE_INFO devHndlInfo[MAX_RAIDMAP_PHYSICAL_DEVICES]; - struct MR_LD_SPAN_MAP ldSpanMap[1]; + struct MR_LD_SPAN_MAP ldSpanMap[]; }; struct IO_REQUEST_INFO { -- 2.27.0
