[PATCH] overflow: Add struct_size_t() helper

Kees Cook
2023-05-23T05:19:42Z

While struct_size() is normally used in situations where the structure
type already has a pointer instance, there are places where no variable
is available. In the past, this has been worked around by using a typed
NULL first argument, but this is a bit ugly. Add a helper to do this,
and replace the handful of instances of the code pattern with it.

Instances were found with this Coccinelle script:

@struct_size_t@
identifier STRUCT, MEMBER;
expression COUNT;
@@

- struct_size((struct STRUCT *)\(0\|NULL\),
+ struct_size_t(struct STRUCT,
MEMBER, COUNT)

Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: James Smart <james.smart@broadcom.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: HighPoint Linux Team <linux@highpoint-tech.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Cc: Don Brace <don.brace@microchip.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: kernel test robot <lkp@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-scsi@vger.kernel.org
Cc: megaraidlinux.pdl@broadcom.com
Cc: storagedev@microchip.com
Cc: linux-xfs@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
Unless there are objections, I'll just take this via my tree...
---
drivers/net/ethernet/intel/ice/ice_ddp.h | 9 ++++-----
drivers/nvme/host/fc.c | 8 ++++----
drivers/scsi/hptiop.c | 4 ++--
drivers/scsi/megaraid/megaraid_sas_base.c | 12 ++++++------
drivers/scsi/megaraid/megaraid_sas_fp.c | 6 +++---
drivers/scsi/smartpqi/smartpqi_init.c | 2 +-
fs/xfs/libxfs/xfs_btree.h | 2 +-
fs/xfs/scrub/btree.h | 2 +-
include/linux/overflow.h | 18 +++++++++++++++++-
lib/overflow_kunit.c | 2 +-
10 files changed, 40 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ddp.h b/drivers/net/ethernet/intel/ice/ice_ddp.h
index 37eadb3d27a8..41acfe26df1c 100644
--- a/drivers/net/ethernet/intel/ice/ice_ddp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ddp.h
@@ -185,7 +185,7 @@ struct ice_buf_hdr {

#define ICE_MAX_ENTRIES_IN_BUF(hd_sz, ent_sz) \
((ICE_PKG_BUF_SIZE - \
- struct_size((struct ice_buf_hdr *)0, section_entry, 1) - (hd_sz)) / \
+ struct_size_t(struct ice_buf_hdr, section_entry, 1) - (hd_sz)) / \
(ent_sz))

/* ice package section IDs */
@@ -297,7 +297,7 @@ struct ice_label_section {
};

#define ICE_MAX_LABELS_IN_BUF \
- ICE_MAX_ENTRIES_IN_BUF(struct_size((struct ice_label_section *)0, \
+ ICE_MAX_ENTRIES_IN_BUF(struct_size_t(struct ice_label_section, \
label, 1) - \
sizeof(struct ice_label), \
sizeof(struct ice_label))
@@ -352,7 +352,7 @@ struct ice_boost_tcam_section {
};

#define ICE_MAX_BST_TCAMS_IN_BUF \
- ICE_MAX_ENTRIES_IN_BUF(struct_size((struct ice_boost_tcam_section *)0, \
+ ICE_MAX_ENTRIES_IN_BUF(struct_size_t(struct ice_boost_tcam_section, \
tcam, 1) - \
sizeof(struct ice_boost_tcam_entry), \
sizeof(struct ice_boost_tcam_entry))
@@ -372,8 +372,7 @@ struct ice_marker_ptype_tcam_section {
};

#define ICE_MAX_MARKER_PTYPE_TCAMS_IN_BUF \
- ICE_MAX_ENTRIES_IN_BUF( \
- struct_size((struct ice_marker_ptype_tcam_section *)0, tcam, \
+ ICE_MAX_ENTRIES_IN_BUF(struct_size_t(struct ice_marker_ptype_tcam_section, tcam, \
1) - \
sizeof(struct ice_marker_ptype_tcam_entry), \
sizeof(struct ice_marker_ptype_tcam_entry))
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 2ed75923507d..691f2df574ce 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2917,8 +2917,8 @@ nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)

ret = nvme_alloc_io_tag_set(&ctrl->ctrl, &ctrl->tag_set,
&nvme_fc_mq_ops, 1,
- struct_size((struct nvme_fcp_op_w_sgl *)NULL, priv,
- ctrl->lport->ops->fcprqst_priv_sz));
+ struct_size_t(struct nvme_fcp_op_w_sgl, priv,
+ ctrl->lport->ops->fcprqst_priv_sz));
if (ret)
return ret;

@@ -3536,8 +3536,8 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,

ret = nvme_alloc_admin_tag_set(&ctrl->ctrl, &ctrl->admin_tag_set,
&nvme_fc_admin_mq_ops,
- struct_size((struct nvme_fcp_op_w_sgl *)NULL, priv,
- ctrl->lport->ops->fcprqst_priv_sz));
+ struct_size_t(struct nvme_fcp_op_w_sgl, priv,
+ ctrl->lport->ops->fcprqst_priv_sz));
if (ret)
goto fail_ctrl;

diff --git a/drivers/scsi/hptiop.c b/drivers/scsi/hptiop.c
index 06ccb51bf6a9..f5334ccbf2ca 100644
--- a/drivers/scsi/hptiop.c
+++ b/drivers/scsi/hptiop.c
@@ -1394,8 +1394,8 @@ static int hptiop_probe(struct pci_dev *pcidev, const struct pci_device_id *id)
host->cmd_per_lun = le32_to_cpu(iop_config.max_requests);
host->max_cmd_len = 16;

- req_size = struct_size((struct hpt_iop_request_scsi_command *)0,
- sg_list, hba->max_sg_descriptors);
+ req_size = struct_size_t(struct hpt_iop_request_scsi_command,
+ sg_list, hba->max_sg_descriptors);
if ((req_size & 0x1f) != 0)
req_size = (req_size + 0x1f) & ~0x1f;

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 317c944c68e3..050eed8e2684 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -5153,8 +5153,8 @@ static void megasas_update_ext_vd_details(struct megasas_instance *instance)
fusion->max_map_sz = ventura_map_sz;
} else {
fusion->old_map_sz =
- struct_size((struct MR_FW_RAID_MAP *)0, ldSpanMap,
- instance->fw_supported_vd_count);
+ struct_size_t(struct MR_FW_RAID_MAP, ldSpanMap,
+ instance->fw_supported_vd_count);
fusion->new_map_sz = sizeof(struct MR_FW_RAID_MAP_EXT);

fusion->max_map_sz =
@@ -5789,8 +5789,8 @@ megasas_setup_jbod_map(struct megasas_instance *instance)
struct fusion_context *fusion = instance->ctrl_context;
size_t pd_seq_map_sz;

- pd_seq_map_sz = struct_size((struct MR_PD_CFG_SEQ_NUM_SYNC *)0, seq,
- MAX_PHYSICAL_DEVICES);
+ pd_seq_map_sz = struct_size_t(struct MR_PD_CFG_SEQ_NUM_SYNC, seq,
+ MAX_PHYSICAL_DEVICES);

instance->use_seqnum_jbod_fp =
instance->support_seqnum_jbod_fp;
@@ -8033,8 +8033,8 @@ static void megasas_detach_one(struct pci_dev *pdev)
if (instance->adapter_type != MFI_SERIES) {
megasas_release_fusion(instance);
pd_seq_map_sz =
- struct_size((struct MR_PD_CFG_SEQ_NUM_SYNC *)0,
- seq, MAX_PHYSICAL_DEVICES);
+ struct_size_t(struct MR_PD_CFG_SEQ_NUM_SYNC,
+ seq, MAX_PHYSICAL_DEVICES);
for (i = 0; i < 2 ; i++) {
if (fusion->ld_map[i])
dma_free_coherent(&instance->pdev->dev,
diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
index 4463a538102a..b8b388a4e28f 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 = struct_size((struct MR_FW_RAID_MAP *)0,
- ldSpanMap,
- le16_to_cpu(pDrvRaidMap->ldCount));
+ expected_size = struct_size_t(struct MR_FW_RAID_MAP,
+ 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/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 03de97cd72c2..f4e0aa262164 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -5015,7 +5015,7 @@ static int pqi_create_queues(struct pqi_ctrl_info *ctrl_info)
}

#define PQI_REPORT_EVENT_CONFIG_BUFFER_LENGTH \
- struct_size((struct pqi_event_config *)0, descriptors, PQI_MAX_EVENT_DESCRIPTORS)
+ struct_size_t(struct pqi_event_config, descriptors, PQI_MAX_EVENT_DESCRIPTORS)

static int pqi_configure_events(struct pqi_ctrl_info *ctrl_info,
bool enable_events)
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index a2aa36b23e25..4d68a58be160 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -301,7 +301,7 @@ struct xfs_btree_cur
static inline size_t
xfs_btree_cur_sizeof(unsigned int nlevels)
{
- return struct_size((struct xfs_btree_cur *)NULL, bc_levels, nlevels);
+ return struct_size_t(struct xfs_btree_cur, bc_levels, nlevels);
}

/* cursor flags */
diff --git a/fs/xfs/scrub/btree.h b/fs/xfs/scrub/btree.h
index 9d7b9ee8bef4..c32b5fad6174 100644
--- a/fs/xfs/scrub/btree.h
+++ b/fs/xfs/scrub/btree.h
@@ -60,7 +60,7 @@ struct xchk_btree {
static inline size_t
xchk_btree_sizeof(unsigned int nlevels)
{
- return struct_size((struct xchk_btree *)NULL, lastkey, nlevels - 1);
+ return struct_size_t(struct xchk_btree, lastkey, nlevels - 1);
}

int xchk_btree(struct xfs_scrub *sc, struct xfs_btree_cur *cur,
diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index 0e33b5cbdb9f..f9b60313eaea 100644
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -283,7 +283,7 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)
* @member: Name of the array member.
* @count: Number of elements in the array.
*
- * Calculates size of memory needed for structure @p followed by an
+ * Calculates size of memory needed for structure of @p followed by an
* array of @count number of @member elements.
*
* Return: number of bytes needed or SIZE_MAX on overflow.
@@ -293,4 +293,20 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)
sizeof(*(p)) + flex_array_size(p, member, count), \
size_add(sizeof(*(p)), flex_array_size(p, member, count)))

+/**
+ * struct_size_t() - Calculate size of structure with trailing flexible array
+ * @type: structure type name.
+ * @member: Name of the array member.
+ * @count: Number of elements in the array.
+ *
+ * Calculates size of memory needed for structure @type followed by an
+ * array of @count number of @member elements. Prefer using struct_size()
+ * when possible instead, to keep calculations associated with a specific
+ * instance variable of type @type.
+ *
+ * Return: number of bytes needed or SIZE_MAX on overflow.
+ */
+#define struct_size_t(type, member, count) \
+ struct_size((type *)NULL, member, count)
+
#endif /* __LINUX_OVERFLOW_H */
diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c
index dcd3ba102db6..34db0b3aa502 100644
--- a/lib/overflow_kunit.c
+++ b/lib/overflow_kunit.c
@@ -649,7 +649,7 @@ struct __test_flex_array {
static void overflow_size_helpers_test(struct kunit *test)
{
/* Make sure struct_size() can be used in a constant expression. */
- u8 ce_array[struct_size((struct __test_flex_array *)0, data, 55)];
+ u8 ce_array[struct_size_t(struct __test_flex_array, data, 55)];
struct __test_flex_array *obj;
int count = 0;
int var;
--
2.34.1