* [PATCH 1/2][next] scsi: hptiop: Replace one-element array with flexible-array member
2022-09-22 16:52 [PATCH 0/2][next] Replace one-element array with flexible-array member Gustavo A. R. Silva
@ 2022-09-22 16:53 ` Gustavo A. R. Silva
2022-09-24 6:01 ` Kees Cook
2022-09-22 16:55 ` [PATCH 2/2][next] scsi: hptiop: Use struct_size() helper in code related to struct hpt_iop_request_scsi_command Gustavo A. R. Silva
2022-09-25 17:03 ` [PATCH 0/2][next] Replace one-element array with flexible-array member Martin K. Petersen
2 siblings, 1 reply; 6+ messages in thread
From: Gustavo A. R. Silva @ 2022-09-22 16:53 UTC (permalink / raw)
To: HighPoint Linux Team, James E.J. Bottomley, Martin K. Petersen
Cc: linux-scsi, linux-kernel, Gustavo A. R. Silva, linux-hardening
One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct hpt_iop_request_scsi_command and refactor the rest of the
code, accordingly.
The following pieces of code suggest that the one element of array sg_list
in struct hpt_iop_request_scsi_command is not taken into account when
calculating the total size for both struct hpt_iop_request_scsi_command
and the maximum number of elements sg_list will contain:
1047 req->header.size = cpu_to_le32(
1048 sizeof(struct hpt_iop_request_scsi_command)
1049 - sizeof(struct hpt_iopsg)
1050 + sg_count * sizeof(struct hpt_iopsg));
1400 req_size = sizeof(struct hpt_iop_request_scsi_command) 1401 + sizeof(struct hpt_iopsg) * (hba->max_sg_descriptors - 1);
So it's safe to replace the one-element array with a flexible-array
member and update the code above, accordingly: now we don't need to
subtract sizeof(struct hpt_iopsg) from sizeof(struct hpt_iop_request_scsi_command)
because this is implicitly done by the flex-array transformation.
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/205
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/scsi/hptiop.c | 3 +--
drivers/scsi/hptiop.h | 2 +-
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/hptiop.c b/drivers/scsi/hptiop.c
index f18b770626e6..cfc6546e35a6 100644
--- a/drivers/scsi/hptiop.c
+++ b/drivers/scsi/hptiop.c
@@ -1046,7 +1046,6 @@ static int hptiop_queuecommand_lck(struct scsi_cmnd *scp)
req->lun = scp->device->lun;
req->header.size = cpu_to_le32(
sizeof(struct hpt_iop_request_scsi_command)
- - sizeof(struct hpt_iopsg)
+ sg_count * sizeof(struct hpt_iopsg));
memcpy(req->cdb, scp->cmnd, sizeof(req->cdb));
@@ -1398,7 +1397,7 @@ static int hptiop_probe(struct pci_dev *pcidev, const struct pci_device_id *id)
host->max_cmd_len = 16;
req_size = sizeof(struct hpt_iop_request_scsi_command)
- + sizeof(struct hpt_iopsg) * (hba->max_sg_descriptors - 1);
+ + sizeof(struct hpt_iopsg) * hba->max_sg_descriptors;
if ((req_size & 0x1f) != 0)
req_size = (req_size + 0x1f) & ~0x1f;
diff --git a/drivers/scsi/hptiop.h b/drivers/scsi/hptiop.h
index 363d5a16243f..ef2f2aca598c 100644
--- a/drivers/scsi/hptiop.h
+++ b/drivers/scsi/hptiop.h
@@ -228,7 +228,7 @@ struct hpt_iop_request_scsi_command {
u8 pad1;
u8 cdb[16];
__le32 dataxfer_length;
- struct hpt_iopsg sg_list[1];
+ struct hpt_iopsg sg_list[];
};
struct hpt_iop_request_ioctl_command {
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 1/2][next] scsi: hptiop: Replace one-element array with flexible-array member
2022-09-22 16:53 ` [PATCH 1/2][next] scsi: hptiop: " Gustavo A. R. Silva
@ 2022-09-24 6:01 ` Kees Cook
0 siblings, 0 replies; 6+ messages in thread
From: Kees Cook @ 2022-09-24 6:01 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: HighPoint Linux Team, James E.J. Bottomley, Martin K. Petersen,
linux-scsi, linux-kernel, linux-hardening
On Thu, Sep 22, 2022 at 11:53:23AM -0500, Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element array with flexible-array
> member in struct hpt_iop_request_scsi_command and refactor the rest of the
> code, accordingly.
>
> The following pieces of code suggest that the one element of array sg_list
> in struct hpt_iop_request_scsi_command is not taken into account when
> calculating the total size for both struct hpt_iop_request_scsi_command
> and the maximum number of elements sg_list will contain:
>
> 1047 req->header.size = cpu_to_le32(
> 1048 sizeof(struct hpt_iop_request_scsi_command)
> 1049 - sizeof(struct hpt_iopsg)
> 1050 + sg_count * sizeof(struct hpt_iopsg));
>
> 1400 req_size = sizeof(struct hpt_iop_request_scsi_command) 1401 + sizeof(struct hpt_iopsg) * (hba->max_sg_descriptors - 1);
Accidentally merge line above ("1401" should start a new line).
> So it's safe to replace the one-element array with a flexible-array
> member and update the code above, accordingly: now we don't need to
> subtract sizeof(struct hpt_iopsg) from sizeof(struct hpt_iop_request_scsi_command)
> because this is implicitly done by the flex-array transformation.
The only binary output change I see is from the line numbers changing
from the patch, as the argument to __might_sleep() is adjusted:
...
│ call d1 <hptiop_reset+0x74>
│ R_X86_64_PLT32 __x86_indirect_thunk_rax-0x4
│ - mov $0x434,%esi
│ + mov $0x433,%esi
│ mov $0x0,%rdi
│ R_X86_64_32S .rodata.str1.1
│ call e2 <hptiop_reset+0x85>
│ R_X86_64_PLT32 __might_sleep-0x4
...
So this looks good!
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2][next] scsi: hptiop: Use struct_size() helper in code related to struct hpt_iop_request_scsi_command
2022-09-22 16:52 [PATCH 0/2][next] Replace one-element array with flexible-array member Gustavo A. R. Silva
2022-09-22 16:53 ` [PATCH 1/2][next] scsi: hptiop: " Gustavo A. R. Silva
@ 2022-09-22 16:55 ` Gustavo A. R. Silva
2022-09-24 6:06 ` Kees Cook
2022-09-25 17:03 ` [PATCH 0/2][next] Replace one-element array with flexible-array member Martin K. Petersen
2 siblings, 1 reply; 6+ messages in thread
From: Gustavo A. R. Silva @ 2022-09-22 16:55 UTC (permalink / raw)
To: HighPoint Linux Team, James E.J. Bottomley, Martin K. Petersen
Cc: linux-scsi, linux-kernel, Gustavo A. R. Silva, linux-hardening
Prefer struct_size() over open-coded versions of idiom:
sizeof(struct-with-flex-array) + sizeof(typeof-flex-array-elements) * count
where count is the max number of items the flexible array is supposed to
contain.
Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/scsi/hptiop.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/hptiop.c b/drivers/scsi/hptiop.c
index cfc6546e35a6..7e8903718245 100644
--- a/drivers/scsi/hptiop.c
+++ b/drivers/scsi/hptiop.c
@@ -1044,9 +1044,7 @@ static int hptiop_queuecommand_lck(struct scsi_cmnd *scp)
req->channel = scp->device->channel;
req->target = scp->device->id;
req->lun = scp->device->lun;
- req->header.size = cpu_to_le32(
- sizeof(struct hpt_iop_request_scsi_command)
- + sg_count * sizeof(struct hpt_iopsg));
+ req->header.size = cpu_to_le32(struct_size(req, sg_list, sg_count));
memcpy(req->cdb, scp->cmnd, sizeof(req->cdb));
hba->ops->post_req(hba, _req);
@@ -1396,8 +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 = sizeof(struct hpt_iop_request_scsi_command)
- + sizeof(struct hpt_iopsg) * hba->max_sg_descriptors;
+ req_size = struct_size((struct hpt_iop_request_scsi_command *)0,
+ sg_list, hba->max_sg_descriptors);
if ((req_size & 0x1f) != 0)
req_size = (req_size + 0x1f) & ~0x1f;
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2][next] Replace one-element array with flexible-array member
2022-09-22 16:52 [PATCH 0/2][next] Replace one-element array with flexible-array member Gustavo A. R. Silva
2022-09-22 16:53 ` [PATCH 1/2][next] scsi: hptiop: " Gustavo A. R. Silva
2022-09-22 16:55 ` [PATCH 2/2][next] scsi: hptiop: Use struct_size() helper in code related to struct hpt_iop_request_scsi_command Gustavo A. R. Silva
@ 2022-09-25 17:03 ` Martin K. Petersen
2 siblings, 0 replies; 6+ messages in thread
From: Martin K. Petersen @ 2022-09-25 17:03 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: HighPoint Linux Team, James E.J. Bottomley, Martin K. Petersen,
linux-scsi, linux-kernel, linux-hardening
Gustavo,
> This series aims to replace one-element arrays with flexible-array
> members in drivers/scsi/hptiop.h
Applied to 6.1/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 6+ messages in thread