From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Linux Media Mailing List <linux-media@vger.kernel.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Ulf Hansson <ulf.hansson@linaro.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Tomi Valkeinen <tomi.valkeinen@ti.com>
Subject: [PATCH] media: videobuf2-dma-contig: fix bad kfree in vb2_dma_contig_clear_max_seg_size
Date: Wed, 20 May 2020 16:15:58 +0300 [thread overview]
Message-ID: <20200520131558.23009-1-tomi.valkeinen@ti.com> (raw)
Commit 9495b7e92f716ab2bd6814fab5e97ab4a39adfdd ("driver core: platform:
Initialize dma_parms for platform devices") in v5.7-rc5 causes
vb2_dma_contig_clear_max_seg_size() to kfree memory that was not
allocated by vb2_dma_contig_set_max_seg_size().
The assumption in vb2_dma_contig_set_max_seg_size() seems to be that
dev->dma_parms is always NULL when the driver is probed, and the case
where dev->dma_parms has bee initialized by someone else than the driver
(by calling vb2_dma_contig_set_max_seg_size) will cause a failure.
All the current users of these functions are platform devices, which now
always have dma_parms set by the driver core. To fix the issue for v5.7,
make vb2_dma_contig_set_max_seg_size() return an error if dma_parms is
NULL to be on the safe side, and remove the kfree code from
vb2_dma_contig_clear_max_seg_size().
For v5.8 we should remove the two functions and move the
dma_set_max_seg_size() calls into the drivers.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
---
Note: I have only fully tested this on linux-next, as the capture driver
I use doesn't support unloading modules in v5.7.
drivers/media/common/videobuf2/videobuf2-dma-contig.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index d3a3ee5b597b..24f80b62ef94 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -726,9 +726,8 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size)
{
if (!dev->dma_parms) {
- dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
- if (!dev->dma_parms)
- return -ENOMEM;
+ dev_err(dev, "Failed to set max_seg_size: dma_parms is NULL\n");
+ return -ENODEV;
}
if (dma_get_max_seg_size(dev) < size)
return dma_set_max_seg_size(dev, size);
@@ -747,8 +746,6 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size);
*/
void vb2_dma_contig_clear_max_seg_size(struct device *dev)
{
- kfree(dev->dma_parms);
- dev->dma_parms = NULL;
}
EXPORT_SYMBOL_GPL(vb2_dma_contig_clear_max_seg_size);
--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
next reply other threads:[~2020-05-20 13:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200520131624eucas1p131198f592ee1009a78e321955c8cae19@eucas1p1.samsung.com>
2020-05-20 13:15 ` Tomi Valkeinen [this message]
2020-05-20 13:30 ` [PATCH] media: videobuf2-dma-contig: fix bad kfree in vb2_dma_contig_clear_max_seg_size Marek Szyprowski
2020-05-20 15:06 ` Ulf Hansson
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=20200520131558.23009-1-tomi.valkeinen@ti.com \
--to=tomi.valkeinen@ti.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=mchehab@kernel.org \
--cc=ulf.hansson@linaro.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).