Re: [PATCH v1] media: meson: vdec: Fix memory leak in error path of vdec_open

[Anand Moon <linux.amoon@gmail.com>]

Hi Nicolas,

Thanks for your review comments.

On Fri, 20 Mar 2026 at 02:05, Nicolas Dufresne <nicolas@ndufresne.ca> wrote:
>
> Hi,
>
> Le mercredi 04 mars 2026 à 15:35 +0530, Anand Moon a écrit :
> > If vdec_init_ctrls(sess) fails, or any subsequent initialization step
> > during vdec_open fails, the control handler allocated for the session
> > is not released. This causes a memory leak of the v4l2_ctrl_handler
> > and its associated control objects.
> >
> > Add a call to v4l2_ctrl_handler_free() in the err_m2m_release error
> > path to ensure resources are properly reclaimed.
> >
> > unreferenced object 0xffff0000205d6878 (size 8):
> >   comm "v4l_id", pid 5289, jiffies 4294938580
> >   hex dump (first 8 bytes):
> >     40 d2 49 18 00 00 ff ff                          @.I.....
> >   backtrace (crc d3204599):
> >     kmemleak_alloc+0xc8/0xf0
> >     __kvmalloc_node_noprof+0x60c/0x850
> >     v4l2_ctrl_handler_init_class+0x1b4/0x2e8 [videodev]
> >     vdec_open+0x1f4/0x788 [meson_vdec]
> >     v4l2_open+0x144/0x460 [videodev]
> >     chrdev_open+0x1ac/0x500
> >     do_dentry_open+0x3f0/0xfe8
> >     vfs_open+0x68/0x320
> >     do_open+0x2d8/0x9a8
> >     path_openat+0x1d0/0x4f0
> >     do_filp_open+0x190/0x380
> >     do_sys_openat2+0xf8/0x1b0
> >     __arm64_sys_openat+0x13c/0x1e8
> >     invoke_syscall+0xdc/0x268
> >     el0_svc_common.constprop.0+0x178/0x258
> >     do_el0_svc+0x4c/0x70
> >
> > Fixes: 3e7f51bd9607 ("media: meson: add v4l2 m2m video decoder driver")
> > Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> > ---
> >  drivers/staging/media/meson/vdec/vdec.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/staging/media/meson/vdec/vdec.c b/drivers/staging/media/meson/vdec/vdec.c
> > index 4b77ec1af5a7..a5ab0c2390f5 100644
> > --- a/drivers/staging/media/meson/vdec/vdec.c
> > +++ b/drivers/staging/media/meson/vdec/vdec.c
> > @@ -914,6 +914,7 @@ static int vdec_open(struct file *file)
> >       return 0;
> >
> >  err_m2m_release:
>
> This goto is used twice. The second time is when vdec_init_ctrls() fails, and in
> that case the v4l2_m2m_ctx is leaded. Can you add the missing label and call
> v4l2_m2m_ctx_release() accordingly. This way we don't have to revisit again.
>
Ok, understood, I will update this in the next version.

Thanks
-Anand