[PATCH] scsi: qedf: Use kzalloc() and add check for bdt_info

[PATCH] scsi: qedf: Use kzalloc() and add check for bdt_info

[Jiasheng Jiang]

Replace kmalloc_array() with kzalloc() to avoid old (dirty) data being
used/freed.
Moreover, add a check for "bdt_info". Otherwise, if one of the allocations
for cmgr->io_bdt_pool[i] fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/scsi/qedf/qedf_io.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..a5970fee6851 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
@@ -254,8 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
+	cmgr->io_bdt_pool = kzalloc(num_ios * sizeof(struct io_bdt *), GFP_KERNEL);
 
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
-- 
2.25.1

Re: [PATCH] scsi: qedf: Use kzalloc() and add check for bdt_info

[Bart Van Assche]

On 1/31/25 11:54 AM, Jiasheng Jiang wrote:
> -	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
> -	    GFP_KERNEL);
> +	cmgr->io_bdt_pool = kzalloc(num_ios * sizeof(struct io_bdt *), GFP_KERNEL);

Please do not reintroduce the possibility of multiplication overflow. 
What is wrong with adding __GFP_ZERO to the second kmalloc_array()
argument or with using kcalloc()? From include/linux/slab.h:

#define kcalloc(n, size, flags) kmalloc_array(n, size, (flags) | __GFP_ZERO)

Thanks,

Bart.

[PATCH v2] scsi: qedf: Use kcalloc() and add check for bdt_info

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.
Moreover, add a check for "bdt_info". Otherwise, if one of the allocations
for cmgr->io_bdt_pool[i] fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v1 -> v2:

1. Replace kzalloc() with kcalloc().
---
 drivers/scsi/qedf/qedf_io.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..abb459e87a86 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(struct io_bdt *), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

Re: [PATCH v2] scsi: qedf: Use kcalloc() and add check for bdt_info

[Markus Elfring]

> Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> used/freed.
> Moreover, add a check for "bdt_info". Otherwise, if one of the allocations
…

Please provide desired changes as separate update steps.

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.13#n81

Regards,
Markus

Re: [PATCH v2] scsi: qedf: Use kcalloc() and add check for bdt_info

[Markus Elfring]

…
> +++ b/drivers/scsi/qedf/qedf_io.c
…
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}

 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
…
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(struct io_bdt *), GFP_KERNEL);
…

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?h=v6.13#n941

Regards,
Markus

[PATCH] Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

[PATCH] scsi: qedf: Add check for bdt_info

[Jiasheng Jiang]

Add a check for "bdt_info". Otherwise, if one of the allocations
for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/scsi/qedf/qedf_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..cab16a3e2a30 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
-- 
2.25.1

[PATCH] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

Re: [PATCH v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Markus Elfring]

> Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> used/freed.…
> ---
>  drivers/scsi/qedf/qedf_io.c | 4 +---
…

Will you become more familiar with patch version descriptions?
https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.13#n310

Regards,
Markus

[PATCH v3] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v2 -> v3:

1. Remove the check for bdt_info.

v1 -> v2:

1. Replace kzalloc() with kcalloc().
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

Re: [PATCH v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Hi Markus,

On Mon, Feb 3, 2025 at 2:20 AM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> > Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> > used/freed.…
> > ---
> >  drivers/scsi/qedf/qedf_io.c | 4 +---
> …
>
> Will you become more familiar with patch version descriptions?
> https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.13#n310
>
> Regards,
> Markus

Thanks, I have submitted a v3 and added the changelog.

-Jiasheng

Re: [v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Markus Elfring]

> Thanks, I have submitted a v3 and added the changelog.
Are you going to improve your version management?
Would a small patch series have been helpful to avoid any confusion here?

Regards,
Markus

[PATCH v3 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v2 -> v3:

1. Remove the check for bdt_info.

v1 -> v2:

1. Replace kzalloc() with kcalloc().
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

[PATCH v3 2/2] scsi: qedf: Add check for bdt_info

[Jiasheng Jiang]

Add a check for "bdt_info". Otherwise, if one of the allocations
for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v2 -> v3:

1. No change.

v1 -> v2:

1. No change.
---
 drivers/scsi/qedf/qedf_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index d52057b97a4f..1ed0ee4f8dde 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
-- 
2.25.1

Re: [v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Hi Markus,

On Tue, Feb 4, 2025 at 3:05 AM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> > Thanks, I have submitted a v3 and added the changelog.
> Are you going to improve your version management?
> Would a small patch series have been helpful to avoid any confusion here?
>
> Regards,
> Markus

Thanks, I have submitted the patch series.

-Jiasheng

Re: [v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Markus Elfring]

> Thanks, I have submitted the patch series.
* Would a cover letter have been helpful?

* Why did you find a “RESEND” relevant already?

* Is there a need to increase version numbers?


Regards,
Markus

Re: [v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Hi Markus,

On Wed, Feb 5, 2025 at 3:12 AM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> > Thanks, I have submitted the patch series.
> * Would a cover letter have been helpful?

Okay, I will resubmit the patech series with a cover letter.

>
> * Why did you find a “RESEND” relevant already?
>

My previous patch missed "Cc: stable", so I resend it.

> * Is there a need to increase version numbers?

Okay, I will keep v2.

-Jiasheng

>
>
> Regards,
> Markus

Re: [v3?] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Markus Elfring]

>> * Is there a need to increase version numbers?
>
> Okay, I will keep v2.
I hope that remaining communication difficulties will be resolved
in other directions.
Are you still looking for better guidance?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/researcher-guidelines.rst?h=v6.13#n5

Regards,
Markus

[PATCH 0/2] scsi: qedf: Replace alloction API and add null check

[Jiasheng Jiang]

This patch series improves memory safety in the qedf SCSI driver by:

1. Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
   used/freed.
2. Add a check for "bdt_info". Otherwise, if one of the allocations
   for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
   pointer dereference.

### Changelog:
#### v2:
- Replace kzalloc() with kcalloc().

Jiasheng Jiang (2):
  scsi: qedf: Replace kmalloc_array() with kcalloc()
  scsi: qedf: Add check for bdt_info

 drivers/scsi/qedf/qedf_io.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

-- 
2.25.1

[PATCH 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

Re: [PATCH 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Greg KH]

On Thu, Feb 06, 2025 at 05:25:22AM +0000, Jiasheng Jiang wrote:
> Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> used/freed.

Used/freed where?

> 
> Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
> Cc: <stable@vger.kernel.org> # v5.10+
> Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
> ---
>  drivers/scsi/qedf/qedf_io.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
> index fcfc3bed02c6..d52057b97a4f 100644
> --- a/drivers/scsi/qedf/qedf_io.c
> +++ b/drivers/scsi/qedf/qedf_io.c
> @@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
>  	}
>  
>  	/* Allocate pool of io_bdts - one for each qedf_ioreq */
> -	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
> -	    GFP_KERNEL);
> -
> +	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);

This is just an array that is then properly all initialized a few lines
below this.

So why does this need to be zeroed out at all?

thanks,

greg k-h

Re: [PATCH 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Greg KH]

On Thu, Feb 06, 2025 at 06:36:58AM +0100, Greg KH wrote:
> On Thu, Feb 06, 2025 at 05:25:22AM +0000, Jiasheng Jiang wrote:
> > Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> > used/freed.
> 
> Used/freed where?
> 
> > 
> > Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
> > Cc: <stable@vger.kernel.org> # v5.10+
> > Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
> > ---
> >  drivers/scsi/qedf/qedf_io.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
> > index fcfc3bed02c6..d52057b97a4f 100644
> > --- a/drivers/scsi/qedf/qedf_io.c
> > +++ b/drivers/scsi/qedf/qedf_io.c
> > @@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
> >  	}
> >  
> >  	/* Allocate pool of io_bdts - one for each qedf_ioreq */
> > -	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
> > -	    GFP_KERNEL);
> > -
> > +	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
> 
> This is just an array that is then properly all initialized a few lines
> below this.
> 
> So why does this need to be zeroed out at all?

Oh, I think I figured it out, but your text for the changelog is wrong,
and needs to be fixed to properly describe what is going on here.

thanks,

greg k-h

[PATCH v2 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changlog:

v1 -> v2:

1. Replace kzalloc() with kcalloc() to not reintroduce the possibility of multiplication overflow.
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

[PATCH v2 2/2] scsi: qedf: Add check for bdt_info

[Jiasheng Jiang]

Add a check for "bdt_info". Otherwise, if one of the allocations
for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v1 -> v2:

1. No change.
---
 drivers/scsi/qedf/qedf_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index d52057b97a4f..1ed0ee4f8dde 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
-- 
2.25.1

Re: [PATCH v2 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Greg KH]

On Thu, Feb 06, 2025 at 07:19:59PM +0000, Jiasheng Jiang wrote:
> Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> used/freed.

"Potentially" being freed.  It will not be used.  And this is only for
an error path that obviously no one has hit before.

Please explain this much better.

thanks,

greg k-h

[PATCH v3 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
potentially used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changlog:

v2 -> v3:

1. Add "potentially" in the commit message to explain this much better.

v1 -> v2:

1. Replace kzalloc() with kcalloc() to not reintroduce the possibility of multiplication overflow.
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

[PATCH v3 2/2] scsi: qedf: Add check for bdt_info

[Jiasheng Jiang]

Add a check for "bdt_info". Otherwise, if one of the allocations
for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v2 -> v3:

1. No change.

v1 -> v2:

1. No change.
---
 drivers/scsi/qedf/qedf_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index d52057b97a4f..1ed0ee4f8dde 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
-- 
2.25.1

Re: [PATCH v2 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Hi Greg,

On Fri, Feb 7, 2025 at 10:10 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Thu, Feb 06, 2025 at 07:19:59PM +0000, Jiasheng Jiang wrote:
> > Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
> > used/freed.
>
> "Potentially" being freed.  It will not be used.  And this is only for
> an error path that obviously no one has hit before.
>
> Please explain this much better.
>
> thanks,
>
> greg k-h

Thanks, I have submitted a v3 and added "potentially" in the commit message.

-Jiasheng

[PATCH 2/2] scsi: qedf: Add check for bdt_info

[Jiasheng Jiang]

Add a check for "bdt_info". Otherwise, if one of the allocations
for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/scsi/qedf/qedf_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index d52057b97a4f..1ed0ee4f8dde 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
-- 
2.25.1

Re: [PATCH v5? 0/2] scsi: qedf: Replace alloction API and add null check

[Markus Elfring]

…
> ### Changelog:
> #### v2:
…

Why did you overlook to increment version numbers once more?
https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.13#n605

Regards,
Markus

[PATCH RESEND v3 1/2] scsi: qedf: Replace kmalloc_array() with kcalloc()

[Jiasheng Jiang]

Replace kmalloc_array() with kcalloc() to avoid old (dirty) data being
used/freed.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v2 -> v3:

1. Remove the check for bdt_info.

v1 -> v2:

1. Replace kzalloc() with kcalloc().
---
 drivers/scsi/qedf/qedf_io.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index fcfc3bed02c6..d52057b97a4f 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
 	}
 
 	/* Allocate pool of io_bdts - one for each qedf_ioreq */
-	cmgr->io_bdt_pool = kmalloc_array(num_ios, sizeof(struct io_bdt *),
-	    GFP_KERNEL);
-
+	cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(*cmgr->io_bdt_pool), GFP_KERNEL);
 	if (!cmgr->io_bdt_pool) {
 		QEDF_WARN(&(qedf->dbg_ctx), "Failed to alloc io_bdt_pool.\n");
 		goto mem_err;
-- 
2.25.1

[PATCH RESEND v3 2/2] scsi: qedf: Add check for bdt_info

[Jiasheng Jiang]

Add a check for "bdt_info". Otherwise, if one of the allocations
for "cmgr->io_bdt_pool[i]" fails, "bdt_info->bd_tbl" will cause a NULL
pointer dereference.

Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
Changelog:

v2 -> v3:

1. No change.

v1 -> v2:

1. No change.
---
 drivers/scsi/qedf/qedf_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index d52057b97a4f..1ed0ee4f8dde 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -125,7 +125,7 @@ void qedf_cmd_mgr_free(struct qedf_cmd_mgr *cmgr)
 	bd_tbl_sz = QEDF_MAX_BDS_PER_CMD * sizeof(struct scsi_sge);
 	for (i = 0; i < num_ios; i++) {
 		bdt_info = cmgr->io_bdt_pool[i];
-		if (bdt_info->bd_tbl) {
+		if (bdt_info && bdt_info->bd_tbl) {
 			dma_free_coherent(&qedf->pdev->dev, bd_tbl_sz,
 			    bdt_info->bd_tbl, bdt_info->bd_tbl_dma);
 			bdt_info->bd_tbl = NULL;
-- 
2.25.1

Re: [PATCH v2] scsi: qedf: Use kcalloc() and add check for bdt_info

[Jiasheng Jiang]

Hi Markus,

On Sun, Feb 2, 2025 at 11:54 AM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> …
> > +++ b/drivers/scsi/qedf/qedf_io.c
> …
> @@ -254,9 +254,7 @@ struct qedf_cmd_mgr *qedf_cmd_mgr_alloc(struct qedf_ctx *qedf)
>         }
>
>         /* Allocate pool of io_bdts - one for each qedf_ioreq */
> …
> +       cmgr->io_bdt_pool = kcalloc(num_ios, sizeof(struct io_bdt *), GFP_KERNEL);
> …
>
> See also:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?h=v6.13#n941
>
> Regards,
> Markus

Thanks, I have split it into two new patches and fixed the error.

-Jiasheng