On Tue, May 21, 2019 at 05:29:35PM +0800, Gen Zhang wrote: > In function con_insert_unipair(), when allocation for p2 and p1[n] > fails, ENOMEM is returned, but previously allocated p1 is not freed, > remains as leaking memory. Thus we should free p1 as well when this > allocation fails. > > Signed-off-by: Gen Zhang <blackgod016...@gmail.com> > > --- > diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c > index b28aa0d..47fbd73 100644 > --- a/drivers/tty/vt/consolemap.c > +++ b/drivers/tty/vt/consolemap.c > @@ -489,7 +489,10 @@ con_insert_unipair(struct uni_pagedir *p, u_short > unicode, u_short fontpos) > p2 = p1[n = (unicode >> 6) & 0x1f]; > if (!p2) { > p2 = p1[n] = kmalloc_array(64, sizeof(u16), GFP_KERNEL); > - if (!p2) return -ENOMEM; > + if (!p2) { > + kfree(p1); > + return -ENOMEM; > + }
This doesn't look safe to me: p->uni_pgdir[n] will still have a handle to the freed memory, won't it? (And please direct these patches to Greg, as he's the current maintainer; I'm happy to stay CCed, of course.) -Kees > memset(p2, 0xff, 64*sizeof(u16)); /* No glyphs for the > characters (yet) */ > } > -- Kees Cook