* [PATCH] media: em28xx: fix memory leak in em28xx_init_dev
@ 2021-11-01 9:55 Dongliang Mu
2021-11-01 18:32 ` Dan Carpenter
0 siblings, 1 reply; 6+ messages in thread
From: Dongliang Mu @ 2021-11-01 9:55 UTC (permalink / raw)
To: Mauro Carvalho Chehab
Cc: Dongliang Mu, Pavel Skripkin, syzbot, linux-media, linux-kernel
In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
to deallocate the media_dev allocated in the em28xx_media_device_init.
Fix this by adding em28xx_unregister_media_device to free media_dev.
BTW, this patch is tested in my local syzkaller instance, and it can
prevent the memory leak from occurring again.
CC: Pavel Skripkin <paskripkin@gmail.com>
Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index c1e0dccb7408..fca68939ca50 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
if (dev->is_audio_only) {
retval = em28xx_audio_setup(dev);
- if (retval)
- return -ENODEV;
+ if (retval) {
+ retval = -ENODEV;
+ goto err_deinit_media;
+ }
em28xx_init_extension(dev);
return 0;
@@ -3645,7 +3647,7 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
dev_err(&dev->intf->dev,
"%s: em28xx_i2c_register bus 0 - error [%d]!\n",
__func__, retval);
- return retval;
+ goto err_deinit_media;
}
/* register i2c bus 1 */
@@ -3661,9 +3663,7 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
"%s: em28xx_i2c_register bus 1 - error [%d]!\n",
__func__, retval);
- em28xx_i2c_unregister(dev, 0);
-
- return retval;
+ goto err_unreg_i2c;
}
}
@@ -3671,6 +3671,13 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
em28xx_card_setup(dev);
return 0;
+
+
+err_unreg_i2c:
+ em28xx_i2c_unregister(dev, 0);
+err_deinit_media:
+ em28xx_unregister_media_device(dev);
+ return retval;
}
static int em28xx_duplicate_dev(struct em28xx *dev)
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] media: em28xx: fix memory leak in em28xx_init_dev
2021-11-01 9:55 [PATCH] media: em28xx: fix memory leak in em28xx_init_dev Dongliang Mu
@ 2021-11-01 18:32 ` Dan Carpenter
2021-11-01 19:28 ` Pavel Skripkin
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2021-11-01 18:32 UTC (permalink / raw)
To: Dongliang Mu
Cc: Mauro Carvalho Chehab, Pavel Skripkin, syzbot, linux-media, linux-kernel
On Mon, Nov 01, 2021 at 05:55:39PM +0800, Dongliang Mu wrote:
> In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
> to deallocate the media_dev allocated in the em28xx_media_device_init.
>
> Fix this by adding em28xx_unregister_media_device to free media_dev.
>
> BTW, this patch is tested in my local syzkaller instance, and it can
> prevent the memory leak from occurring again.
>
> CC: Pavel Skripkin <paskripkin@gmail.com>
> Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
Is this really a syzbot warning? If so it should be in the format:
Reported-by: syzbot+4c4ffd1e1094dae61035@syzkaller.appspotmail.com
Syzbot is different from syzkaller. Syzkaller is the fuzzer and syzbot
is the program which reports syzkaller bugs.
> ---
> drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
> index c1e0dccb7408..fca68939ca50 100644
> --- a/drivers/media/usb/em28xx/em28xx-cards.c
> +++ b/drivers/media/usb/em28xx/em28xx-cards.c
> @@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
>
There is no check to see if the em28xx_media_device_init() fails. I
don't love that we call unregister() to undo the init() but it seems
like it should work...
> if (dev->is_audio_only) {
> retval = em28xx_audio_setup(dev);
> - if (retval)
> - return -ENODEV;
> + if (retval) {
> + retval = -ENODEV;
This was in the original code, but probably we should preserve the
error code.
> + goto err_deinit_media;
> + }
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] media: em28xx: fix memory leak in em28xx_init_dev
2021-11-01 18:32 ` Dan Carpenter
@ 2021-11-01 19:28 ` Pavel Skripkin
2021-11-02 6:31 ` Dongliang Mu
0 siblings, 1 reply; 6+ messages in thread
From: Pavel Skripkin @ 2021-11-01 19:28 UTC (permalink / raw)
To: Dan Carpenter, Dongliang Mu
Cc: Mauro Carvalho Chehab, syzbot, linux-media, linux-kernel
On 11/1/21 21:32, Dan Carpenter wrote:
> On Mon, Nov 01, 2021 at 05:55:39PM +0800, Dongliang Mu wrote:
>> In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
>> to deallocate the media_dev allocated in the em28xx_media_device_init.
>>
>> Fix this by adding em28xx_unregister_media_device to free media_dev.
>>
>> BTW, this patch is tested in my local syzkaller instance, and it can
>> prevent the memory leak from occurring again.
>>
>> CC: Pavel Skripkin <paskripkin@gmail.com>
>> Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
>> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
>> Reported-by: syzbot <syzkaller@googlegroups.com>
>
> Is this really a syzbot warning? If so it should be in the format:
>
> Reported-by: syzbot+4c4ffd1e1094dae61035@syzkaller.appspotmail.com
>
> Syzbot is different from syzkaller. Syzkaller is the fuzzer and syzbot
> is the program which reports syzkaller bugs.
>
Bug report is from his local instance. He just wants to give credit to
syzbot for finding it
>> ---
>> drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
>> 1 file changed, 13 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
>> index c1e0dccb7408..fca68939ca50 100644
>> --- a/drivers/media/usb/em28xx/em28xx-cards.c
>> +++ b/drivers/media/usb/em28xx/em28xx-cards.c
>> @@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
>>
>
> There is no check to see if the em28xx_media_device_init() fails. I
I guess, it should work, since there a lot of checks to see if this
pointer is valid, i.e driver can work even without this pointer, AFAIK
> don't love that we call unregister() to undo the init() but it seems
> like it should work...
Same here, but it is out of scope of this patch :)
With regards,
Pavel Skripkin
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] media: em28xx: fix memory leak in em28xx_init_dev
2021-11-01 19:28 ` Pavel Skripkin
@ 2021-11-02 6:31 ` Dongliang Mu
2021-11-02 13:50 ` Dan Carpenter
0 siblings, 1 reply; 6+ messages in thread
From: Dongliang Mu @ 2021-11-02 6:31 UTC (permalink / raw)
To: Pavel Skripkin
Cc: Dan Carpenter, Mauro Carvalho Chehab, syzbot, linux-media, linux-kernel
On Tue, Nov 2, 2021 at 3:28 AM Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> On 11/1/21 21:32, Dan Carpenter wrote:
> > On Mon, Nov 01, 2021 at 05:55:39PM +0800, Dongliang Mu wrote:
> >> In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
> >> to deallocate the media_dev allocated in the em28xx_media_device_init.
> >>
> >> Fix this by adding em28xx_unregister_media_device to free media_dev.
> >>
> >> BTW, this patch is tested in my local syzkaller instance, and it can
> >> prevent the memory leak from occurring again.
> >>
> >> CC: Pavel Skripkin <paskripkin@gmail.com>
> >> Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
> >> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> >> Reported-by: syzbot <syzkaller@googlegroups.com>
> >
> > Is this really a syzbot warning? If so it should be in the format:
> >
> > Reported-by: syzbot+4c4ffd1e1094dae61035@syzkaller.appspotmail.com
> >
> > Syzbot is different from syzkaller. Syzkaller is the fuzzer and syzbot
> > is the program which reports syzkaller bugs.
> >
>
> Bug report is from his local instance. He just wants to give credit to
> syzbot for finding it
Hi Dan,
just as explained by Pavel, I leveraged the local syzkaller instance
to find this bug.
I can modify it to "Reported-by: syzkaller
<syzkaller@googlegroups.com>", this one looks better.
>
> >> ---
> >> drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
> >> 1 file changed, 13 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
> >> index c1e0dccb7408..fca68939ca50 100644
> >> --- a/drivers/media/usb/em28xx/em28xx-cards.c
> >> +++ b/drivers/media/usb/em28xx/em28xx-cards.c
> >> @@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
> >>
> >
> > There is no check to see if the em28xx_media_device_init() fails. I
>
> I guess, it should work, since there a lot of checks to see if this
> pointer is valid, i.e driver can work even without this pointer, AFAIK
>
> > don't love that we call unregister() to undo the init() but it seems
> > like it should work...
>
> Same here, but it is out of scope of this patch :)
From the implementation, em28xx_media_device_init and
em28xx_unregister_media_device should not be a pair of functions
(do/undo).
Maybe I can write em28xx_free_media_device to be paired with
em28xx_media_device_init, like below. And then only call it from the
error handling context.
static void em28xx_free_media_device(struct em28xx *dev)
{
#ifdef CONFIG_MEDIA_CONTROLLER
kfree(dev->media_dev);
dev->media_dev = NULL;
#endif
}
>
>
>
> With regards,
> Pavel Skripkin
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] media: em28xx: fix memory leak in em28xx_init_dev
2021-11-02 6:31 ` Dongliang Mu
@ 2021-11-02 13:50 ` Dan Carpenter
2021-11-08 1:06 ` Dongliang Mu
0 siblings, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2021-11-02 13:50 UTC (permalink / raw)
To: Dongliang Mu
Cc: Pavel Skripkin, Mauro Carvalho Chehab, syzbot, linux-media, linux-kernel
On Tue, Nov 02, 2021 at 02:31:26PM +0800, Dongliang Mu wrote:
> On Tue, Nov 2, 2021 at 3:28 AM Pavel Skripkin <paskripkin@gmail.com> wrote:
> >
> > On 11/1/21 21:32, Dan Carpenter wrote:
> > > On Mon, Nov 01, 2021 at 05:55:39PM +0800, Dongliang Mu wrote:
> > >> In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
> > >> to deallocate the media_dev allocated in the em28xx_media_device_init.
> > >>
> > >> Fix this by adding em28xx_unregister_media_device to free media_dev.
> > >>
> > >> BTW, this patch is tested in my local syzkaller instance, and it can
> > >> prevent the memory leak from occurring again.
> > >>
> > >> CC: Pavel Skripkin <paskripkin@gmail.com>
> > >> Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
> > >> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> > >> Reported-by: syzbot <syzkaller@googlegroups.com>
> > >
> > > Is this really a syzbot warning? If so it should be in the format:
> > >
> > > Reported-by: syzbot+4c4ffd1e1094dae61035@syzkaller.appspotmail.com
> > >
> > > Syzbot is different from syzkaller. Syzkaller is the fuzzer and syzbot
> > > is the program which reports syzkaller bugs.
> > >
> >
> > Bug report is from his local instance. He just wants to give credit to
> > syzbot for finding it
>
> Hi Dan,
>
> just as explained by Pavel, I leveraged the local syzkaller instance
> to find this bug.
>
> I can modify it to "Reported-by: syzkaller
> <syzkaller@googlegroups.com>", this one looks better.
>
No need for a Reported-by at all, but if you want to credit syzkaller
that's an okay format.
> >
> > >> ---
> > >> drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
> > >> 1 file changed, 13 insertions(+), 6 deletions(-)
> > >>
> > >> diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
> > >> index c1e0dccb7408..fca68939ca50 100644
> > >> --- a/drivers/media/usb/em28xx/em28xx-cards.c
> > >> +++ b/drivers/media/usb/em28xx/em28xx-cards.c
> > >> @@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
> > >>
> > >
> > > There is no check to see if the em28xx_media_device_init() fails. I
> >
> > I guess, it should work, since there a lot of checks to see if this
> > pointer is valid, i.e driver can work even without this pointer, AFAIK
> >
> > > don't love that we call unregister() to undo the init() but it seems
> > > like it should work...
> >
> > Same here, but it is out of scope of this patch :)
>
> >From the implementation, em28xx_media_device_init and
> em28xx_unregister_media_device should not be a pair of functions
> (do/undo).
>
That's how it is now, but it's not necessarily how it should be. Anyway,
it's unrelated to you patch. Just forget I mentioned it.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] media: em28xx: fix memory leak in em28xx_init_dev
2021-11-02 13:50 ` Dan Carpenter
@ 2021-11-08 1:06 ` Dongliang Mu
0 siblings, 0 replies; 6+ messages in thread
From: Dongliang Mu @ 2021-11-08 1:06 UTC (permalink / raw)
To: Dan Carpenter
Cc: Pavel Skripkin, Mauro Carvalho Chehab, syzbot, linux-media, linux-kernel
On Tue, Nov 2, 2021 at 9:51 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Tue, Nov 02, 2021 at 02:31:26PM +0800, Dongliang Mu wrote:
> > On Tue, Nov 2, 2021 at 3:28 AM Pavel Skripkin <paskripkin@gmail.com> wrote:
> > >
> > > On 11/1/21 21:32, Dan Carpenter wrote:
> > > > On Mon, Nov 01, 2021 at 05:55:39PM +0800, Dongliang Mu wrote:
> > > >> In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
> > > >> to deallocate the media_dev allocated in the em28xx_media_device_init.
> > > >>
> > > >> Fix this by adding em28xx_unregister_media_device to free media_dev.
> > > >>
> > > >> BTW, this patch is tested in my local syzkaller instance, and it can
> > > >> prevent the memory leak from occurring again.
> > > >>
> > > >> CC: Pavel Skripkin <paskripkin@gmail.com>
> > > >> Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
> > > >> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> > > >> Reported-by: syzbot <syzkaller@googlegroups.com>
> > > >
> > > > Is this really a syzbot warning? If so it should be in the format:
> > > >
> > > > Reported-by: syzbot+4c4ffd1e1094dae61035@syzkaller.appspotmail.com
> > > >
> > > > Syzbot is different from syzkaller. Syzkaller is the fuzzer and syzbot
> > > > is the program which reports syzkaller bugs.
> > > >
> > >
> > > Bug report is from his local instance. He just wants to give credit to
> > > syzbot for finding it
> >
> > Hi Dan,
> >
> > just as explained by Pavel, I leveraged the local syzkaller instance
> > to find this bug.
> >
> > I can modify it to "Reported-by: syzkaller
> > <syzkaller@googlegroups.com>", this one looks better.
> >
>
> No need for a Reported-by at all, but if you want to credit syzkaller
> that's an okay format.
>
Hi all,
do I need to send a v2 patch with a new Reported-by tag?
> > >
> > > >> ---
> > > >> drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
> > > >> 1 file changed, 13 insertions(+), 6 deletions(-)
> > > >>
> > > >> diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
> > > >> index c1e0dccb7408..fca68939ca50 100644
> > > >> --- a/drivers/media/usb/em28xx/em28xx-cards.c
> > > >> +++ b/drivers/media/usb/em28xx/em28xx-cards.c
> > > >> @@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
> > > >>
> > > >
> > > > There is no check to see if the em28xx_media_device_init() fails. I
> > >
> > > I guess, it should work, since there a lot of checks to see if this
> > > pointer is valid, i.e driver can work even without this pointer, AFAIK
> > >
> > > > don't love that we call unregister() to undo the init() but it seems
> > > > like it should work...
> > >
> > > Same here, but it is out of scope of this patch :)
> >
> > >From the implementation, em28xx_media_device_init and
> > em28xx_unregister_media_device should not be a pair of functions
> > (do/undo).
> >
>
> That's how it is now, but it's not necessarily how it should be. Anyway,
> it's unrelated to you patch. Just forget I mentioned it.
>
> regards,
> dan carpenter
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-11-08 1:06 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-01 9:55 [PATCH] media: em28xx: fix memory leak in em28xx_init_dev Dongliang Mu
2021-11-01 18:32 ` Dan Carpenter
2021-11-01 19:28 ` Pavel Skripkin
2021-11-02 6:31 ` Dongliang Mu
2021-11-02 13:50 ` Dan Carpenter
2021-11-08 1:06 ` Dongliang Mu
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