Messages in this thread | | | Date | Sat, 2 May 2020 17:57:29 +0200 | From | Sam Ravnborg <> | Subject | Re: [PATCH] vt: fix unicode console freeing with a common interface |
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Hi Nicolas
On Sat, May 02, 2020 at 11:01:07AM -0400, Nicolas Pitre wrote: > By directly using kfree() in different places we risk missing one if > it is switched to using vfree(), especially if the corresponding > vmalloc() is hidden away within a common abstraction. > > Oh wait, that's exactly what happened here. > > So let's fix this by creating a common abstraction for the free case > as well. > > Signed-off-by: Nicolas Pitre <nico@fluxnic.net> > Reported-by: syzbot+0bfda3ade1ee9288a1be@syzkaller.appspotmail.com > Fixes: 9a98e7a80f95 ("vt: don't use kmalloc() for the unicode screen buffer") > Cc: <stable@vger.kernel.org>
Looks good. Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Not the I know the code, but verified that no more kfree() was used for vc_uni_screen.
Sam
> > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c > index e5ffed795e..48a8199f78 100644 > --- a/drivers/tty/vt/vt.c > +++ b/drivers/tty/vt/vt.c > @@ -365,9 +365,14 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows) > return uniscr; > } > > +static void vc_uniscr_free(struct uni_screen *uniscr) > +{ > + vfree(uniscr); > +} > + > static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr) > { > - vfree(vc->vc_uni_screen); > + vc_uniscr_free(vc->vc_uni_screen); > vc->vc_uni_screen = new_uniscr; > } > > @@ -1230,7 +1235,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc, > err = resize_screen(vc, new_cols, new_rows, user); > if (err) { > kfree(newscreen); > - kfree(new_uniscr); > + vc_uniscr_free(new_uniscr); > return err; > } >
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