* [PATCH] zram: Fix buffer size passed to strlcpy()
@ 2017-07-28 17:12 Matthias Kaehlcke
2017-08-02 22:54 ` Doug Anderson
0 siblings, 1 reply; 4+ messages in thread
From: Matthias Kaehlcke @ 2017-07-28 17:12 UTC (permalink / raw)
To: Minchan Kim, Nitin Gupta, Sergey Senozhatsky
Cc: linux-kernel, Doug Anderson, Matthias Kaehlcke
comp_algorithm_store() passes the size of the source buffer to strlcpy()
instead of the destination buffer size, fix this.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
drivers/block/zram/zram_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 856d5dc02451..7d2ddffad361 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -327,7 +327,7 @@ static ssize_t comp_algorithm_store(struct device *dev,
return -EBUSY;
}
- strlcpy(zram->compressor, compressor, sizeof(compressor));
+ strlcpy(zram->compressor, compressor, sizeof(zram->compressor));
up_write(&zram->init_lock);
return len;
}
--
2.14.0.rc0.400.g1c36432dff-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] zram: Fix buffer size passed to strlcpy()
2017-07-28 17:12 [PATCH] zram: Fix buffer size passed to strlcpy() Matthias Kaehlcke
@ 2017-08-02 22:54 ` Doug Anderson
2017-08-02 23:44 ` Minchan Kim
0 siblings, 1 reply; 4+ messages in thread
From: Doug Anderson @ 2017-08-02 22:54 UTC (permalink / raw)
To: Matthias Kaehlcke
Cc: Minchan Kim, Nitin Gupta, Sergey Senozhatsky, linux-kernel
Hi,
On Fri, Jul 28, 2017 at 10:12 AM, Matthias Kaehlcke <mka@chromium.org> wrote:
> comp_algorithm_store() passes the size of the source buffer to strlcpy()
> instead of the destination buffer size, fix this.
This was introduced in commit 415403be37e2 ("zram: use crypto api to
check alg availability"), but probably don't need a "Fixes" since
there's not really a bug (see below)
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> drivers/block/zram/zram_drv.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 856d5dc02451..7d2ddffad361 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -327,7 +327,7 @@ static ssize_t comp_algorithm_store(struct device *dev,
> return -EBUSY;
> }
>
> - strlcpy(zram->compressor, compressor, sizeof(compressor));
> + strlcpy(zram->compressor, compressor, sizeof(zram->compressor));
As far as I can tell the two sizes are identical. In struct zram:
char compressor[CRYPTO_MAX_ALG_NAME];
Locally here:
char compressor[CRYPTO_MAX_ALG_NAME];
...so there is no bug per say unless there's a hidden "#undef".
...but your change does make it a little clearer, plus if someone ever
changed one of these arrays it would be safer. Thus:
Reviewed-by: Douglas Anderson <dianders@chromium.org>
I suppose another option would be to define the local array based on
the size of the structure. AKA locally in the function:
char compressor[ARRAY_SIZE(zram->compressor)];
...if you did that you could replace the strlcpy() below with a simple
strcpy() since you'd be guaranteed that there's be enough space.
...but I'm probably overthinking it too much. ;-P
-Doug
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] zram: Fix buffer size passed to strlcpy()
2017-08-02 22:54 ` Doug Anderson
@ 2017-08-02 23:44 ` Minchan Kim
2017-08-02 23:59 ` Matthias Kaehlcke
0 siblings, 1 reply; 4+ messages in thread
From: Minchan Kim @ 2017-08-02 23:44 UTC (permalink / raw)
To: Doug Anderson
Cc: Matthias Kaehlcke, Nitin Gupta, Sergey Senozhatsky, linux-kernel
Hi Doug,
On Wed, Aug 02, 2017 at 03:54:32PM -0700, Doug Anderson wrote:
> Hi,
>
> On Fri, Jul 28, 2017 at 10:12 AM, Matthias Kaehlcke <mka@chromium.org> wrote:
> > comp_algorithm_store() passes the size of the source buffer to strlcpy()
> > instead of the destination buffer size, fix this.
>
> This was introduced in commit 415403be37e2 ("zram: use crypto api to
> check alg availability"), but probably don't need a "Fixes" since
> there's not really a bug (see below)
>
> > Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> > ---
> > drivers/block/zram/zram_drv.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > index 856d5dc02451..7d2ddffad361 100644
> > --- a/drivers/block/zram/zram_drv.c
> > +++ b/drivers/block/zram/zram_drv.c
> > @@ -327,7 +327,7 @@ static ssize_t comp_algorithm_store(struct device *dev,
> > return -EBUSY;
> > }
> >
> > - strlcpy(zram->compressor, compressor, sizeof(compressor));
> > + strlcpy(zram->compressor, compressor, sizeof(zram->compressor));
>
> As far as I can tell the two sizes are identical. In struct zram:
>
> char compressor[CRYPTO_MAX_ALG_NAME];
>
> Locally here:
>
> char compressor[CRYPTO_MAX_ALG_NAME];
>
> ...so there is no bug per say unless there's a hidden "#undef".
> ...but your change does make it a little clearer, plus if someone ever
> changed one of these arrays it would be safer. Thus:
>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
>
>
> I suppose another option would be to define the local array based on
> the size of the structure. AKA locally in the function:
>
> char compressor[ARRAY_SIZE(zram->compressor)];
>
> ...if you did that you could replace the strlcpy() below with a simple
> strcpy() since you'd be guaranteed that there's be enough space.
> ...but I'm probably overthinking it too much. ;-P
First of all, Thanks for the patch, Matthias. You are correct and you
patch doesn't have any problem. However, I think Doug's suggestion
looks better. Could you mind resending?
Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] zram: Fix buffer size passed to strlcpy()
2017-08-02 23:44 ` Minchan Kim
@ 2017-08-02 23:59 ` Matthias Kaehlcke
0 siblings, 0 replies; 4+ messages in thread
From: Matthias Kaehlcke @ 2017-08-02 23:59 UTC (permalink / raw)
To: Minchan Kim; +Cc: Doug Anderson, Nitin Gupta, Sergey Senozhatsky, linux-kernel
El Thu, Aug 03, 2017 at 08:44:37AM +0900 Minchan Kim ha dit:
> Hi Doug,
>
> On Wed, Aug 02, 2017 at 03:54:32PM -0700, Doug Anderson wrote:
> > Hi,
> >
> > On Fri, Jul 28, 2017 at 10:12 AM, Matthias Kaehlcke <mka@chromium.org> wrote:
> > > comp_algorithm_store() passes the size of the source buffer to strlcpy()
> > > instead of the destination buffer size, fix this.
> >
> > This was introduced in commit 415403be37e2 ("zram: use crypto api to
> > check alg availability"), but probably don't need a "Fixes" since
> > there's not really a bug (see below)
> >
> > > Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> > > ---
> > > drivers/block/zram/zram_drv.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> > > index 856d5dc02451..7d2ddffad361 100644
> > > --- a/drivers/block/zram/zram_drv.c
> > > +++ b/drivers/block/zram/zram_drv.c
> > > @@ -327,7 +327,7 @@ static ssize_t comp_algorithm_store(struct device *dev,
> > > return -EBUSY;
> > > }
> > >
> > > - strlcpy(zram->compressor, compressor, sizeof(compressor));
> > > + strlcpy(zram->compressor, compressor, sizeof(zram->compressor));
> >
> > As far as I can tell the two sizes are identical. In struct zram:
> >
> > char compressor[CRYPTO_MAX_ALG_NAME];
> >
> > Locally here:
> >
> > char compressor[CRYPTO_MAX_ALG_NAME];
> >
> > ...so there is no bug per say unless there's a hidden "#undef".
> > ...but your change does make it a little clearer, plus if someone ever
> > changed one of these arrays it would be safer. Thus:
> >
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
> >
> >
> > I suppose another option would be to define the local array based on
> > the size of the structure. AKA locally in the function:
> >
> > char compressor[ARRAY_SIZE(zram->compressor)];
> >
> > ...if you did that you could replace the strlcpy() below with a simple
> > strcpy() since you'd be guaranteed that there's be enough space.
> > ...but I'm probably overthinking it too much. ;-P
>
> First of all, Thanks for the patch, Matthias. You are correct and you
> patch doesn't have any problem. However, I think Doug's suggestion
> looks better. Could you mind resending?
Sure, I can rework the patch.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-08-02 23:59 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-07-28 17:12 [PATCH] zram: Fix buffer size passed to strlcpy() Matthias Kaehlcke
2017-08-02 22:54 ` Doug Anderson
2017-08-02 23:44 ` Minchan Kim
2017-08-02 23:59 ` Matthias Kaehlcke
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.