* [PATCH] dax: replace sprintf() by scnprintf()
@ 2021-07-10 16:46 Salah Triki
2021-07-10 17:04 ` Joe Perches
0 siblings, 1 reply; 5+ messages in thread
From: Salah Triki @ 2021-07-10 16:46 UTC (permalink / raw)
To: dan.j.williams, vishal.l.verma, dave.jiang; +Cc: nvdimm, linux-kernel
Replace sprintf() by scnprintf() in order to avoid buffer overflows.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
---
drivers/dax/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 5aee26e1bbd6..bcae4be6ae76 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -76,7 +76,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf,
fields = sscanf(buf, "dax%d.%d", ®ion_id, &id);
if (fields != 2)
return -EINVAL;
- sprintf(devname, "dax%d.%d", region_id, id);
+ scnprintf(devname, DAX_NAME_LEN, "dax%d.%d", region_id, id);
if (!sysfs_streq(buf, devname))
return -EINVAL;
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] dax: replace sprintf() by scnprintf()
2021-07-10 16:46 [PATCH] dax: replace sprintf() by scnprintf() Salah Triki
@ 2021-07-10 17:04 ` Joe Perches
2021-07-12 12:26 ` Salah Triki
0 siblings, 1 reply; 5+ messages in thread
From: Joe Perches @ 2021-07-10 17:04 UTC (permalink / raw)
To: Salah Triki, dan.j.williams, vishal.l.verma, dave.jiang
Cc: nvdimm, linux-kernel
On Sat, 2021-07-10 at 17:46 +0100, Salah Triki wrote:
> Replace sprintf() by scnprintf() in order to avoid buffer overflows.
OK but also not strictly necessary. DAX_NAME_LEN is 30.
Are you finding and changing these manually or with a script?
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
[]
> @@ -76,7 +76,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf,
> fields = sscanf(buf, "dax%d.%d", ®ion_id, &id);
> if (fields != 2)
> return -EINVAL;
> - sprintf(devname, "dax%d.%d", region_id, id);
> + scnprintf(devname, DAX_NAME_LEN, "dax%d.%d", region_id, id);
> if (!sysfs_streq(buf, devname))
> return -EINVAL;
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dax: replace sprintf() by scnprintf()
2021-07-10 17:04 ` Joe Perches
@ 2021-07-12 12:26 ` Salah Triki
2021-07-12 16:14 ` Joe Perches
0 siblings, 1 reply; 5+ messages in thread
From: Salah Triki @ 2021-07-12 12:26 UTC (permalink / raw)
To: Joe Perches
Cc: dan.j.williams, vishal.l.verma, dave.jiang, nvdimm, linux-kernel
On Sat, Jul 10, 2021 at 10:04:48AM -0700, Joe Perches wrote:
> On Sat, 2021-07-10 at 17:46 +0100, Salah Triki wrote:
> > Replace sprintf() by scnprintf() in order to avoid buffer overflows.
>
> OK but also not strictly necessary. DAX_NAME_LEN is 30.
>
> Are you finding and changing these manually or with a script?
>
> > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> []
> > @@ -76,7 +76,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf,
> > fields = sscanf(buf, "dax%d.%d", ®ion_id, &id);
> > if (fields != 2)
> > return -EINVAL;
> > - sprintf(devname, "dax%d.%d", region_id, id);
> > + scnprintf(devname, DAX_NAME_LEN, "dax%d.%d", region_id, id);
> > if (!sysfs_streq(buf, devname))
> > return -EINVAL;
> >
> >
>
>
since region_id and id are unsigned long may be devname should be
char[21].
I'm finding and changing these manually.
Thanx
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dax: replace sprintf() by scnprintf()
2021-07-12 12:26 ` Salah Triki
@ 2021-07-12 16:14 ` Joe Perches
2021-07-12 16:48 ` Salah Triki
0 siblings, 1 reply; 5+ messages in thread
From: Joe Perches @ 2021-07-12 16:14 UTC (permalink / raw)
To: Salah Triki
Cc: dan.j.williams, vishal.l.verma, dave.jiang, nvdimm, linux-kernel
On Mon, 2021-07-12 at 13:26 +0100, Salah Triki wrote:
> On Sat, Jul 10, 2021 at 10:04:48AM -0700, Joe Perches wrote:
> > On Sat, 2021-07-10 at 17:46 +0100, Salah Triki wrote:
> > > Replace sprintf() by scnprintf() in order to avoid buffer overflows.
> >
> > OK but also not strictly necessary. DAX_NAME_LEN is 30.
> >
> > Are you finding and changing these manually or with a script?
> >
> > > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> > []
> > > @@ -76,7 +76,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf,
> > > fields = sscanf(buf, "dax%d.%d", ®ion_id, &id);
> > > if (fields != 2)
> > > return -EINVAL;
> > > - sprintf(devname, "dax%d.%d", region_id, id);
> > > + scnprintf(devname, DAX_NAME_LEN, "dax%d.%d", region_id, id);
> > > if (!sysfs_streq(buf, devname))
> > > return -EINVAL;
> > >
> > >
> >
> >
>
> since region_id and id are unsigned long may be devname should be
> char[21].
I think you need to look at the code a bit more carefully.
unsigned int region_id, id;
Also the output is %d, so the maximum length of each output
int is 10 with a possible leading minus sign.
3 + 10 + 1 + 10 + 1. So 25 not 21 which is too small.
The %d uses could be changed to %u to make it 23.
But really it hardly matters as 30 is sufficent and the
function call depth here isn't particularly high.
> I'm finding and changing these manually.
coccinelle could help.
https://coccinelle.gitlabpages.inria.fr/website/
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dax: replace sprintf() by scnprintf()
2021-07-12 16:14 ` Joe Perches
@ 2021-07-12 16:48 ` Salah Triki
0 siblings, 0 replies; 5+ messages in thread
From: Salah Triki @ 2021-07-12 16:48 UTC (permalink / raw)
To: Joe Perches
Cc: dan.j.williams, vishal.l.verma, dave.jiang, nvdimm, linux-kernel
On Mon, Jul 12, 2021 at 09:14:53AM -0700, Joe Perches wrote:
> On Mon, 2021-07-12 at 13:26 +0100, Salah Triki wrote:
> > On Sat, Jul 10, 2021 at 10:04:48AM -0700, Joe Perches wrote:
> > > On Sat, 2021-07-10 at 17:46 +0100, Salah Triki wrote:
> > > > Replace sprintf() by scnprintf() in order to avoid buffer overflows.
> > >
> > > OK but also not strictly necessary. DAX_NAME_LEN is 30.
> > >
> > > Are you finding and changing these manually or with a script?
> > >
> > > > diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> > > []
> > > > @@ -76,7 +76,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf,
> > > > fields = sscanf(buf, "dax%d.%d", ®ion_id, &id);
> > > > if (fields != 2)
> > > > return -EINVAL;
> > > > - sprintf(devname, "dax%d.%d", region_id, id);
> > > > + scnprintf(devname, DAX_NAME_LEN, "dax%d.%d", region_id, id);
> > > > if (!sysfs_streq(buf, devname))
> > > > return -EINVAL;
> > > >
> > > >
> > >
> > >
> >
> > since region_id and id are unsigned long may be devname should be
> > char[21].
>
> I think you need to look at the code a bit more carefully.
>
> unsigned int region_id, id;
>
> Also the output is %d, so the maximum length of each output
> int is 10 with a possible leading minus sign.
>
> 3 + 10 + 1 + 10 + 1. So 25 not 21 which is too small.
>
> The %d uses could be changed to %u to make it 23.
> But really it hardly matters as 30 is sufficent and the
> function call depth here isn't particularly high.
>
> > I'm finding and changing these manually.
>
> coccinelle could help.
> https://coccinelle.gitlabpages.inria.fr/website/
>
>
Thanx
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-07-10 16:46 [PATCH] dax: replace sprintf() by scnprintf() Salah Triki
2021-07-10 17:04 ` Joe Perches
2021-07-12 12:26 ` Salah Triki
2021-07-12 16:14 ` Joe Perches
2021-07-12 16:48 ` Salah Triki
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