From: Jens Wiklander <jens.wiklander@linaro.org>
To: Souptick Joarder <jrdr.linux@gmail.com>
Cc: op-tee@lists.trustedfirmware.org, linux-kernel@vger.kernel.org,
John Hubbard <jhubbard@nvidia.com>
Subject: Re: [PATCH] tee/tee_shm.c: Fix error handling path
Date: Sun, 13 Sep 2020 22:29:09 +0200 [thread overview]
Message-ID: <20200913202909.GA1018725@jade> (raw)
In-Reply-To: <1599972131-31770-1-git-send-email-jrdr.linux@gmail.com>
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
next prev parent reply other threads:[~2020-09-13 20:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-13 4:42 [PATCH] tee/tee_shm.c: Fix error handling path Souptick Joarder
2020-09-13 20:29 ` Jens Wiklander [this message]
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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