Nouveau - Oct 2020 - [PATCH RFC] drm/nouveau: fix memory leak in nvkm_iccsense_oneinit

struct pw_rail_t is allocated as an array in function nvios_iccsense_parse,
and stored to a struct member of local variable. However, the array is not
freed when the local variable becomes invalid, and the reference is not
passed on, leading to a memory leak.

Fix this by freeing struct pw_rail_t when exiting nvkm_iccsense_oneinit.

Signed-off-by: Keita Suzuki <keitasuzuki.park at sslab.ics.keio.ac.jp>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
index fecfa6afcf54..8ba8d8e3f52a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
@@ -280,8 +280,10 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
 			}
 
 			rail = kmalloc(sizeof(*rail), GFP_KERNEL);
-			if (!rail)
+			if (!rail) {
+				kfree(stbl.rail);
 				return -ENOMEM;
+			}
 
 			rail->read = read;
 			rail->sensor = sensor;
@@ -291,6 +293,7 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
 			list_add_tail(&rail->head, &iccsense->rails);
 		}
 	}
+	kfree(stbl.rail);
 	return 0;
 }
 
-- 
2.17.1

Ben, I think this is like the 5th patch tackling this issue, I think
we should merge one of those.

On Thu, Oct 15, 2020 at 6:23 AM Keita Suzuki
<keitasuzuki.park at sslab.ics.keio.ac.jp> wrote:
>
> struct pw_rail_t is allocated as an array in function nvios_iccsense_parse,
> and stored to a struct member of local variable. However, the array is not
> freed when the local variable becomes invalid, and the reference is not
> passed on, leading to a memory leak.
>
> Fix this by freeing struct pw_rail_t when exiting nvkm_iccsense_oneinit.
>
> Signed-off-by: Keita Suzuki <keitasuzuki.park at
sslab.ics.keio.ac.jp>
> ---
>  drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
> index fecfa6afcf54..8ba8d8e3f52a 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
> @@ -280,8 +280,10 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
>                         }
>
>                         rail = kmalloc(sizeof(*rail), GFP_KERNEL);
> -                       if (!rail)
> +                       if (!rail) {
> +                               kfree(stbl.rail);
>                                 return -ENOMEM;
> +                       }
>
>                         rail->read = read;
>                         rail->sensor = sensor;
> @@ -291,6 +293,7 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
>                         list_add_tail(&rail->head,
&iccsense->rails);
>                 }
>         }
> +       kfree(stbl.rail);
>         return 0;
>  }
>
> --
> 2.17.1
>
> _______________________________________________
> Nouveau mailing list
> Nouveau at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/nouveau
>

On Thu, Oct 15, 2020 at 6:32 PM Karol Herbst <kherbst at redhat.com>
wrote:
>
> Ben, I think this is like the 5th patch tackling this issue, I think
> we should merge one of those.
>
maybe I just confused that with reports, but it seems to turn up quite
a bit and maybe I should have pushed more of it as well...

Anyway, the patch itself looks good.

Reviewed-by: Karol Herbst <kherbst at redhat.com>
> On Thu, Oct 15, 2020 at 6:23 AM Keita Suzuki
> <keitasuzuki.park at sslab.ics.keio.ac.jp> wrote:
> >
> > struct pw_rail_t is allocated as an array in function
nvios_iccsense_parse,
> > and stored to a struct member of local variable. However, the array is
not
> > freed when the local variable becomes invalid, and the reference is
not
> > passed on, leading to a memory leak.
> >
> > Fix this by freeing struct pw_rail_t when exiting
nvkm_iccsense_oneinit.
> >
> > Signed-off-by: Keita Suzuki <keitasuzuki.park at
sslab.ics.keio.ac.jp>
> > ---
> >  drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
> > index fecfa6afcf54..8ba8d8e3f52a 100644
> > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
> > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/iccsense/base.c
> > @@ -280,8 +280,10 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
> >                         }
> >
> >                         rail = kmalloc(sizeof(*rail), GFP_KERNEL);
> > -                       if (!rail)
> > +                       if (!rail) {
> > +                               kfree(stbl.rail);
> >                                 return -ENOMEM;
> > +                       }
> >
> >                         rail->read = read;
> >                         rail->sensor = sensor;
> > @@ -291,6 +293,7 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
> >                         list_add_tail(&rail->head,
&iccsense->rails);
> >                 }
> >         }
> > +       kfree(stbl.rail);
> >         return 0;
> >  }
> >
> > --
> > 2.17.1
> >
> > _______________________________________________
> > Nouveau mailing list
> > Nouveau at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/nouveau
> >