From: Stanimir Varbanov <stanimir.varbanov@linaro.org>
To: Mansur Alisha Shaik <mansur@codeaurora.org>, linux-media@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
vgarodia@codeaurora.org
Subject: Re: [RESEND 3/3] venus: handle use after free for iommu_map/iommu_unmap
Date: Mon, 10 Aug 2020 12:53:22 +0300 [thread overview]
Message-ID: <c16db389-cdba-0735-a25e-8d5063d998cf@linaro.org> (raw)
In-Reply-To: <1596781478-12216-4-git-send-email-mansur@codeaurora.org>
Hi,
On 8/7/20 9:24 AM, Mansur Alisha Shaik wrote:
> In concurrency usecase and reboot scenario we are trying
> to map fw.iommu_domain which is already unmapped during
I guess you want to say "to unmap iommu domain which is already unmapped" ?
> shutdown. This is causing NULL pointer dereference crash.
>
> This case is handled by adding necessary checks.
>
> Call trace:
> __iommu_map+0x4c/0x348
> iommu_map+0x5c/0x70
> venus_boot+0x184/0x230 [venus_core]
> venus_sys_error_handler+0xa0/0x14c [venus_core]
> process_one_work+0x210/0x3d0
> worker_thread+0x248/0x3f4
> kthread+0x11c/0x12c
> ret_from_fork+0x10/0x18
>
> Signed-off-by: Mansur Alisha Shaik <mansur@codeaurora.org>
> ---
> drivers/media/platform/qcom/venus/firmware.c | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
> index 8801a6a..c427e88 100644
> --- a/drivers/media/platform/qcom/venus/firmware.c
> +++ b/drivers/media/platform/qcom/venus/firmware.c
> @@ -171,9 +171,14 @@ static int venus_shutdown_no_tz(struct venus_core *core)
>
> iommu = core->fw.iommu_domain;
>
> - unmapped = iommu_unmap(iommu, VENUS_FW_START_ADDR, mapped);
> - if (unmapped != mapped)
> - dev_err(dev, "failed to unmap firmware\n");
> + if (core->fw.mapped_mem_size && iommu) {
> + unmapped = iommu_unmap(iommu, VENUS_FW_START_ADDR, mapped);
> +
> + if (unmapped != mapped)
> + dev_err(dev, "failed to unmap firmware\n");
> + else
> + core->fw.mapped_mem_size = 0;
> + }
>
> return 0;
> }
> @@ -288,7 +293,11 @@ void venus_firmware_deinit(struct venus_core *core)
> iommu = core->fw.iommu_domain;
>
> iommu_detach_device(iommu, core->fw.dev);
> - iommu_domain_free(iommu);
> +
> + if (core->fw.iommu_domain) {
> + iommu_domain_free(iommu);
> + core->fw.iommu_domain = NULL;
> + }
>
> platform_device_unregister(to_platform_device(core->fw.dev));
> }
>
--
regards,
Stan
next prev parent reply other threads:[~2020-08-10 9:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-07 6:24 [RESEND 0/3] Venus - Handle race conditions in concurrency Mansur Alisha Shaik
2020-08-07 6:24 ` [RESEND 1/3] venus: core: handle race condititon for core ops Mansur Alisha Shaik
2020-08-10 9:50 ` Stanimir Varbanov
2020-08-21 10:59 ` Stanimir Varbanov
2020-08-25 1:43 ` mansur
2020-09-10 10:43 ` Stanimir Varbanov
2020-08-07 6:24 ` [RESEND 2/3] venus: core: cancel pending work items in workqueue Mansur Alisha Shaik
2020-08-07 6:24 ` [RESEND 3/3] venus: handle use after free for iommu_map/iommu_unmap Mansur Alisha Shaik
2020-08-10 9:53 ` Stanimir Varbanov [this message]
2020-08-25 13:13 ` Stanimir Varbanov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c16db389-cdba-0735-a25e-8d5063d998cf@linaro.org \
--to=stanimir.varbanov@linaro.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=mansur@codeaurora.org \
--cc=vgarodia@codeaurora.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).