* [PATCH] nvme: work around -Wformat-security warning
@ 2026-09-16 11:44 Arnd Bergmann
2026-09-17 3:40 ` Damien Le Moal
` (3 more replies)
0 siblings, 4 replies; 6+ messages in thread
From: Arnd Bergmann @ 2026-09-16 11:44 UTC (permalink / raw)
To: Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg,
Maurizio Lombardi
Cc: Arnd Bergmann, Hannes Reinecke, Nilay Shroff, John Garry,
Martin K. Petersen, linux-nvme, linux-kernel
From: Arnd Bergmann <arnd@arndb.de>
Passing a string variable into dev_set_name() causes a warning
when building with -Wformat-security enabled:
drivers/nvme/host/core.c: In function 'nvme_cdev_add':
drivers/nvme/host/core.c:3911:9: error: format not a string literal and no format arguments [-Werror=format-security]
3911 | ret = dev_set_name(cdev_device, name);
Remove the temporary strings and let dev_set_name() do the
same thing internally.
Fixes: 26acdaa357cd ("nvme: fix crash and memory leak during invalid cdev teardown")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/nvme/host/core.c | 21 +++++++++------------
drivers/nvme/host/multipath.c | 12 +++++-------
drivers/nvme/host/nvme.h | 6 +++---
3 files changed, 17 insertions(+), 22 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index beea23d04a70..79f6a2c7923e 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3931,9 +3931,9 @@ void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device)
put_device(cdev_device);
}
-int nvme_cdev_add(const char *name, struct cdev *cdev,
- struct device *cdev_device,
- const struct file_operations *fops, struct module *owner)
+int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
+ const struct file_operations *fops, struct module *owner,
+ int ctrl, int head)
{
int minor, ret;
@@ -3941,7 +3941,7 @@ int nvme_cdev_add(const char *name, struct cdev *cdev,
if (minor < 0)
return minor;
- ret = dev_set_name(cdev_device, name);
+ ret = dev_set_name(cdev_device, "ng%dn%d", ctrl, head);
if (ret) {
ida_free(&nvme_ns_chr_minor_ida, minor);
return ret;
@@ -3982,17 +3982,14 @@ static const struct file_operations nvme_ns_chr_fops = {
static void nvme_add_ns_cdev(struct nvme_ns *ns)
{
- char name[32];
-
ns->cdev_device.parent = ns->ctrl->device;
- snprintf(name, sizeof(name), "ng%dn%d", ns->ctrl->instance,
- ns->head->instance);
nvme_get_ns(ns); /* Undone in nvme_cdev_rel() */
- if (nvme_cdev_add(name, &ns->cdev, &ns->cdev_device,
- &nvme_ns_chr_fops, ns->ctrl->ops->module)) {
- dev_err(ns->ctrl->device, "Unable to create the %s device\n",
- name);
+ if (nvme_cdev_add(&ns->cdev, &ns->cdev_device,
+ &nvme_ns_chr_fops, ns->ctrl->ops->module,
+ ns->ctrl->instance, ns->head->instance)) {
+ dev_err(ns->ctrl->device, "Unable to create the ng%dn%d device\n",
+ ns->ctrl->instance, ns->head->instance);
nvme_put_ns(ns);
return;
}
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 75dbb58286a3..3d46c4f28a47 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -646,17 +646,15 @@ static const struct file_operations nvme_ns_head_chr_fops = {
static void nvme_add_ns_head_cdev(struct nvme_ns_head *head)
{
- char name[32];
-
head->cdev_device.parent = &head->subsys->dev;
- snprintf(name, sizeof(name), "ng%dn%d", head->subsys->instance,
- head->instance);
nvme_get_ns_head(head); /* Undone in nvme_cdev_rel() */
- if (nvme_cdev_add(name, &head->cdev, &head->cdev_device,
- &nvme_ns_head_chr_fops, THIS_MODULE)) {
+ if (nvme_cdev_add(&head->cdev, &head->cdev_device,
+ &nvme_ns_head_chr_fops, THIS_MODULE,
+ head->subsys->instance, head->instance)) {
dev_err(disk_to_dev(head->disk),
- "Unable to create the %s device\n", name);
+ "Unable to create the ng%dn%d device\n",
+ head->subsys->instance, head->instance);
nvme_put_ns_head(head);
return;
}
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 2cff9fcbf740..e0260f4d24fd 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -1013,9 +1013,9 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp, u8 csi,
void nvme_get_ns_head(struct nvme_ns_head *head);
bool nvme_tryget_ns_head(struct nvme_ns_head *head);
void nvme_put_ns_head(struct nvme_ns_head *head);
-int nvme_cdev_add(const char *name, struct cdev *cdev,
- struct device *cdev_device,
- const struct file_operations *fops, struct module *owner);
+int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
+ const struct file_operations *fops, struct module *owner,
+ int ctrl, int head);
void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device);
int nvme_ioctl(struct block_device *bdev, blk_mode_t mode,
unsigned int cmd, unsigned long arg);
--
2.53.0
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nvme: work around -Wformat-security warning
2026-09-16 11:44 [PATCH] nvme: work around -Wformat-security warning Arnd Bergmann
@ 2026-09-17 3:40 ` Damien Le Moal
2026-09-17 4:14 ` Nilay Shroff
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Damien Le Moal @ 2026-09-17 3:40 UTC (permalink / raw)
To: Arnd Bergmann, Keith Busch, Jens Axboe, Christoph Hellwig,
Sagi Grimberg, Maurizio Lombardi
Cc: Arnd Bergmann, Hannes Reinecke, Nilay Shroff, John Garry,
Martin K. Petersen, linux-nvme, linux-kernel
On 2026/09/16 18:44, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> Passing a string variable into dev_set_name() causes a warning
> when building with -Wformat-security enabled:
>
> drivers/nvme/host/core.c: In function 'nvme_cdev_add':
> drivers/nvme/host/core.c:3911:9: error: format not a string literal and no format arguments [-Werror=format-security]
> 3911 | ret = dev_set_name(cdev_device, name);
>
> Remove the temporary strings and let dev_set_name() do the
> same thing internally.
>
> Fixes: 26acdaa357cd ("nvme: fix crash and memory leak during invalid cdev teardown")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Looks OK to me.
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
--
Damien Le Moal
Western Digital Research
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nvme: work around -Wformat-security warning
2026-09-16 11:44 [PATCH] nvme: work around -Wformat-security warning Arnd Bergmann
2026-09-17 3:40 ` Damien Le Moal
@ 2026-09-17 4:14 ` Nilay Shroff
2026-09-17 5:59 ` Arnd Bergmann
2026-09-17 8:01 ` John Garry
2026-09-17 8:18 ` Nilay Shroff
3 siblings, 1 reply; 6+ messages in thread
From: Nilay Shroff @ 2026-09-17 4:14 UTC (permalink / raw)
To: Arnd Bergmann, Keith Busch, Jens Axboe, Christoph Hellwig,
Sagi Grimberg, Maurizio Lombardi
Cc: Arnd Bergmann, Hannes Reinecke, John Garry, Martin K. Petersen,
linux-nvme, linux-kernel
On 9/16/26 5:14 PM, Arnd Bergmann wrote:
> From: Arnd Bergmann<arnd@arndb.de>
>
> Passing a string variable into dev_set_name() causes a warning
> when building with -Wformat-security enabled:
>
> drivers/nvme/host/core.c: In function 'nvme_cdev_add':
> drivers/nvme/host/core.c:3911:9: error: format not a string literal and no format arguments [-Werror=format-security]
> 3911 | ret = dev_set_name(cdev_device, name);
>
> Remove the temporary strings and let dev_set_name() do the
> same thing internally.
>
> Fixes: 26acdaa357cd ("nvme: fix crash and memory leak during invalid cdev teardown")
> Signed-off-by: Arnd Bergmann<arnd@arndb.de>
The changes look good. However, I applied the patch and built
drivers/nvme/ with -Wformat-security, and I still see a couple of
additional warnings:
$ make M=drivers/nvme/ KCFLAGS="-Wformat-security"
make[1]: Entering directory '/home/nilay/Development/linux-x86/drivers/nvme'
[...]
host/sysfs.c: In function ‘cntrltype_show’:
host/sysfs.c:682:9: error: format not a string literal and no format arguments [-Werror=format-security]
682 | return sysfs_emit(buf, type[ctrl->cntrltype]);
| ^~~~~~
host/sysfs.c: In function ‘dctype_show’:
host/sysfs.c:699:9: error: format not a string literal and no format arguments [-Werror=format-security]
699 | return sysfs_emit(buf, type[ctrl->dctype]);
| ^~~~~~
I think that if we're fixing -Wformat-security warnings in the NVMe
driver, it would be useful to address above warnings as part of this
patch as well.
Thanks,
--Nilay
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nvme: work around -Wformat-security warning
2026-09-17 4:14 ` Nilay Shroff
@ 2026-09-17 5:59 ` Arnd Bergmann
0 siblings, 0 replies; 6+ messages in thread
From: Arnd Bergmann @ 2026-09-17 5:59 UTC (permalink / raw)
To: Nilay Shroff, Arnd Bergmann, Keith Busch, Jens Axboe,
Christoph Hellwig, Sagi Grimberg, Maurizio Lombardi
Cc: Hannes Reinecke, John Garry, Martin K. Petersen, linux-nvme,
linux-kernel
On Thu, Sep 17, 2026, at 06:14, Nilay Shroff wrote:
> On 9/16/26 5:14 PM, Arnd Bergmann wrote:
>
> The changes look good. However, I applied the patch and built
> drivers/nvme/ with -Wformat-security, and I still see a couple of
> additional warnings:
>
> $ make M=drivers/nvme/ KCFLAGS="-Wformat-security"
> make[1]: Entering directory
> '/home/nilay/Development/linux-x86/drivers/nvme'
> [...]
> host/sysfs.c: In function ‘cntrltype_show’:
> host/sysfs.c:682:9: error: format not a string literal and no format
> arguments [-Werror=format-security]
> 682 | return sysfs_emit(buf, type[ctrl->cntrltype]);
> | ^~~~~~
> host/sysfs.c: In function ‘dctype_show’:
> host/sysfs.c:699:9: error: format not a string literal and no format
> arguments [-Werror=format-security]
> 699 | return sysfs_emit(buf, type[ctrl->dctype]);
> | ^~~~~~
>
> I think that if we're fixing -Wformat-security warnings in the NVMe
> driver, it would be useful to address above warnings as part of this
> patch as well.
Good point, I forgot to check for the patches I already had fixed
in my randconfig branch and only addressed the new one here. I'll
send a separate patch to fix the two instance above.
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nvme: work around -Wformat-security warning
2026-09-16 11:44 [PATCH] nvme: work around -Wformat-security warning Arnd Bergmann
2026-09-17 3:40 ` Damien Le Moal
2026-09-17 4:14 ` Nilay Shroff
@ 2026-09-17 8:01 ` John Garry
2026-09-17 8:18 ` Nilay Shroff
3 siblings, 0 replies; 6+ messages in thread
From: John Garry @ 2026-09-17 8:01 UTC (permalink / raw)
To: Arnd Bergmann, Keith Busch, Jens Axboe, Christoph Hellwig,
Sagi Grimberg, Maurizio Lombardi
Cc: Arnd Bergmann, Hannes Reinecke, Nilay Shroff, John Garry,
Martin K. Petersen, linux-nvme, linux-kernel
On 9/16/26 12:44, Arnd Bergmann wrote:
> From: Arnd Bergmann<arnd@arndb.de>
>
> Passing a string variable into dev_set_name() causes a warning
> when building with -Wformat-security enabled:
>
> drivers/nvme/host/core.c: In function 'nvme_cdev_add':
> drivers/nvme/host/core.c:3911:9: error: format not a string literal and no format arguments [-Werror=format-security]
> 3911 | ret = dev_set_name(cdev_device, name);
>
> Remove the temporary strings and let dev_set_name() do the
> same thing internally.
>
Prior to 26acdaa357cd, we had the caller of nvme_cdev_add() also calling
dev_set_name(). Maybe it is better to revert to that (but keep the
functionality to set NVME_NSHEAD_CDEV_LIVE). But then put_device() call
for errors becomes a bit messy.
...
> }
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 2cff9fcbf740..e0260f4d24fd 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -1013,9 +1013,9 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp, u8 csi,
> void nvme_get_ns_head(struct nvme_ns_head *head);
> bool nvme_tryget_ns_head(struct nvme_ns_head *head);
> void nvme_put_ns_head(struct nvme_ns_head *head);
> -int nvme_cdev_add(const char *name, struct cdev *cdev,
> - struct device *cdev_device,
> - const struct file_operations *fops, struct module *owner);
> +int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
> + const struct file_operations *fops, struct module *owner,
> + int ctrl, int head);
nit: maybe @head arg would be better called "ns", as it is the "ns" index.
> void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device);
> int nvme_ioctl(struct block_device *bdev, blk_mode_t mode,
> unsigned int cmd, unsigned long arg);
> -- 2.53.0
Regardless of comments:
Reviewed-by: John Garry <john.garry@linux.dev>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nvme: work around -Wformat-security warning
2026-09-16 11:44 [PATCH] nvme: work around -Wformat-security warning Arnd Bergmann
` (2 preceding siblings ...)
2026-09-17 8:01 ` John Garry
@ 2026-09-17 8:18 ` Nilay Shroff
3 siblings, 0 replies; 6+ messages in thread
From: Nilay Shroff @ 2026-09-17 8:18 UTC (permalink / raw)
To: Arnd Bergmann, Keith Busch, Jens Axboe, Christoph Hellwig,
Sagi Grimberg, Maurizio Lombardi
Cc: Arnd Bergmann, Hannes Reinecke, John Garry, Martin K. Petersen,
linux-nvme, linux-kernel
On 9/16/26 5:14 PM, Arnd Bergmann wrote:
> From: Arnd Bergmann<arnd@arndb.de>
>
> Passing a string variable into dev_set_name() causes a warning
> when building with -Wformat-security enabled:
>
> drivers/nvme/host/core.c: In function 'nvme_cdev_add':
> drivers/nvme/host/core.c:3911:9: error: format not a string literal and no format arguments [-Werror=format-security]
> 3911 | ret = dev_set_name(cdev_device, name);
>
> Remove the temporary strings and let dev_set_name() do the
> same thing internally.
>
> Fixes: 26acdaa357cd ("nvme: fix crash and memory leak during invalid cdev teardown")
> Signed-off-by: Arnd Bergmann<arnd@arndb.de>
Looks good to me.
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-09-17 8:18 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2026-09-16 11:44 [PATCH] nvme: work around -Wformat-security warning Arnd Bergmann
2026-09-17 3:40 ` Damien Le Moal
2026-09-17 4:14 ` Nilay Shroff
2026-09-17 5:59 ` Arnd Bergmann
2026-09-17 8:01 ` John Garry
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