* [PATCH] tee/tee_shm.c: Fix error handling path
@ 2020-09-13 4:42 Souptick Joarder
2020-09-13 20:29 ` Jens Wiklander
0 siblings, 1 reply; 5+ messages in thread
From: Souptick Joarder @ 2020-09-13 4:42 UTC (permalink / raw)
To: jens.wiklander; +Cc: op-tee, linux-kernel, Souptick Joarder, John Hubbard
When shm->num_pages <= 0, we should avoid calling
release_registered_pages() in error handling path.
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
---
drivers/tee/tee_shm.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 00472f5..e517d9f 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -260,8 +260,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
kfree(kiov);
}
- if (rc > 0)
- shm->num_pages = rc;
+ shm->num_pages = rc;
if (rc != num_pages) {
if (rc >= 0)
rc = -ENOMEM;
@@ -309,7 +308,9 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
idr_remove(&teedev->idr, shm->id);
mutex_unlock(&teedev->mutex);
}
- release_registered_pages(shm);
+ if (shm->pages && (shm->num_pages > 0))
+ release_registered_pages(shm);
+
}
kfree(shm);
teedev_ctx_put(ctx);
--
1.9.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] tee/tee_shm.c: Fix error handling path
2020-09-13 4:42 [PATCH] tee/tee_shm.c: Fix error handling path Souptick Joarder
@ 2020-09-13 20:29 ` Jens Wiklander
2020-09-14 1:39 ` Souptick Joarder
0 siblings, 1 reply; 5+ messages in thread
From: Jens Wiklander @ 2020-09-13 20:29 UTC (permalink / raw)
To: Souptick Joarder; +Cc: op-tee, linux-kernel, John Hubbard
On Sun, Sep 13, 2020 at 10:12:11AM +0530, Souptick Joarder wrote:
> When shm->num_pages <= 0, we should avoid calling
> release_registered_pages() in error handling path.
What are we fixing?
>
> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> Cc: John Hubbard <jhubbard@nvidia.com>
> ---
> drivers/tee/tee_shm.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index 00472f5..e517d9f 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -260,8 +260,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
> kfree(kiov);
> }
> - if (rc > 0)
> - shm->num_pages = rc;
> + shm->num_pages = rc;
Why not avoiding assigning invalid values to shm->num_pages?
By the way, shm->num_pages is a size_t.
> if (rc != num_pages) {
> if (rc >= 0)
> rc = -ENOMEM;
> @@ -309,7 +308,9 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> idr_remove(&teedev->idr, shm->id);
> mutex_unlock(&teedev->mutex);
> }
> - release_registered_pages(shm);
> + if (shm->pages && (shm->num_pages > 0))
> + release_registered_pages(shm);
> +
With this we'll leak if shm->pages has been assigned something.
> }
> kfree(shm);
> teedev_ctx_put(ctx);
> --
> 1.9.1
>
Thanks,
Jens
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] tee/tee_shm.c: Fix error handling path
2020-09-13 20:29 ` Jens Wiklander
@ 2020-09-14 1:39 ` Souptick Joarder
0 siblings, 0 replies; 5+ messages in thread
From: Souptick Joarder @ 2020-09-14 1:39 UTC (permalink / raw)
To: Jens Wiklander; +Cc: op-tee, linux-kernel, John Hubbard
On Mon, Sep 14, 2020 at 1:59 AM Jens Wiklander
<jens.wiklander@linaro.org> wrote:
>
> On Sun, Sep 13, 2020 at 10:12:11AM +0530, Souptick Joarder wrote:
> > When shm->num_pages <= 0, we should avoid calling
> > release_registered_pages() in error handling path.
> What are we fixing?
Current code is working fine and this patch is not needed. Sorry for the noise.
>
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
> > Cc: John Hubbard <jhubbard@nvidia.com>
> > ---
> > drivers/tee/tee_shm.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > index 00472f5..e517d9f 100644
> > --- a/drivers/tee/tee_shm.c
> > +++ b/drivers/tee/tee_shm.c
> > @@ -260,8 +260,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> > rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
> > kfree(kiov);
> > }
> > - if (rc > 0)
> > - shm->num_pages = rc;
> > + shm->num_pages = rc;
> Why not avoiding assigning invalid values to shm->num_pages?
> By the way, shm->num_pages is a size_t.
>
> > if (rc != num_pages) {
> > if (rc >= 0)
> > rc = -ENOMEM;
> > @@ -309,7 +308,9 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
> > idr_remove(&teedev->idr, shm->id);
> > mutex_unlock(&teedev->mutex);
> > }
> > - release_registered_pages(shm);
> > + if (shm->pages && (shm->num_pages > 0))
> > + release_registered_pages(shm);
> > +
> With this we'll leak if shm->pages has been assigned something.
>
> > }
> > kfree(shm);
> > teedev_ctx_put(ctx);
> > -
^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <641dfe3b-1de8-97ea-eac7-89d81846eab3@web.de>]
* Re: [PATCH] tee/tee_shm.c: Fix error handling path
[not found] <641dfe3b-1de8-97ea-eac7-89d81846eab3@web.de>
@ 2020-09-13 13:01 ` Souptick Joarder
0 siblings, 0 replies; 5+ messages in thread
From: Souptick Joarder @ 2020-09-13 13:13 UTC (permalink / raw)
To: Markus Elfring
Cc: op-tee, linux-kernel, kernel-janitors, Jens Wiklander, John Hubbard
On Sun, Sep 13, 2020 at 2:00 PM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> > When shm->num_pages <= 0, we should avoid calling
> > release_registered_pages() in error handling path.
>
> * Would an imperative wording become helpful for the change description?
>
> * I suggest to add the tag “Fixes” to the commit message.
Sure. Will address both in v2.
>
> Regards,
> Markus
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] tee/tee_shm.c: Fix error handling path
@ 2020-09-13 13:01 ` Souptick Joarder
0 siblings, 0 replies; 5+ messages in thread
From: Souptick Joarder @ 2020-09-13 13:01 UTC (permalink / raw)
To: Markus Elfring
Cc: op-tee, linux-kernel, kernel-janitors, Jens Wiklander, John Hubbard
On Sun, Sep 13, 2020 at 2:00 PM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> > When shm->num_pages <= 0, we should avoid calling
> > release_registered_pages() in error handling path.
>
> * Would an imperative wording become helpful for the change description?
>
> * I suggest to add the tag “Fixes” to the commit message.
Sure. Will address both in v2.
>
> Regards,
> Markus
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-09-14 1:39 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2020-09-13 4:42 [PATCH] tee/tee_shm.c: Fix error handling path Souptick Joarder
2020-09-13 20:29 ` Jens Wiklander
2020-09-14 1:39 ` Souptick Joarder
[not found] <641dfe3b-1de8-97ea-eac7-89d81846eab3@web.de>
2020-09-13 13:13 ` Souptick Joarder
2020-09-13 13:01 ` Souptick Joarder
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