vt: don't use kmalloc() for the unicode screen buffer
commit 9a98e7a80f
upstream.
Even if the actual screen size is bounded in vc_do_resize(), the unicode
buffer is still a little more than twice the size of the glyph buffer
and may exceed MAX_ORDER down the kmalloc() path. This can be triggered
from user space.
Since there is no point having a physically contiguous buffer here,
let's avoid the above issue as well as reducing pressure on high order
allocations by using vmalloc() instead.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Cc: <stable@vger.kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/nycvar.YSQ.7.76.2003282214210.2671@knanqh.ubzr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
b027b30d14
commit
64882aa0c5
|
@ -81,6 +81,7 @@
|
|||
#include <linux/errno.h>
|
||||
#include <linux/kd.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/vmalloc.h>
|
||||
#include <linux/major.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/console.h>
|
||||
|
@ -350,7 +351,7 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
|
|||
/* allocate everything in one go */
|
||||
memsize = cols * rows * sizeof(char32_t);
|
||||
memsize += rows * sizeof(char32_t *);
|
||||
p = kmalloc(memsize, GFP_KERNEL);
|
||||
p = vmalloc(memsize);
|
||||
if (!p)
|
||||
return NULL;
|
||||
|
||||
|
@ -366,7 +367,7 @@ static struct uni_screen *vc_uniscr_alloc(unsigned int cols, unsigned int rows)
|
|||
|
||||
static void vc_uniscr_set(struct vc_data *vc, struct uni_screen *new_uniscr)
|
||||
{
|
||||
kfree(vc->vc_uni_screen);
|
||||
vfree(vc->vc_uni_screen);
|
||||
vc->vc_uni_screen = new_uniscr;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in New Issue