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authorLinus Torvalds <torvalds@linux-foundation.org>2022-07-08 21:03:26 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-07-08 21:03:26 +0300
commit086ff84617185393a0bbf25830c4f36412a7d3f4 (patch)
treea5771a4c2d845577c05b059547ff6a3a36d1cbd3
parente8a4e1c1bb697b1d9fc48f0e56dc0f50bc024bee (diff)
parent53a6e66b1b4fea4b52f8bc62e5f9530af9061027 (diff)
downloadlinux-086ff84617185393a0bbf25830c4f36412a7d3f4.tar.xz
Merge tag 'for-5.19/fbdev-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev
Pull fbdev fixes from Helge Deller: - fbcon now prevents switching to screen resolutions which are smaller than the font size, and prevents enabling a font which is bigger than the current screen resolution. This fixes vmalloc-out-of-bounds accesses found by KASAN. - Guiling Deng fixed a bug where the centered fbdev logo wasn't displayed correctly if the screen size matched the logo size. - Hsin-Yi Wang provided a patch to include errno.h to fix build when CONFIG_OF isn't enabled. * tag 'for-5.19/fbdev-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev: fbcon: Use fbcon_info_from_console() in fbcon_modechange_possible() fbmem: Check virtual screen sizes in fb_set_var() fbcon: Prevent that screen size is smaller than font size fbcon: Disallow setting font bigger than screen size video: of_display_timing.h: include errno.h fbdev: fbmem: Fix logo center image dx issue
-rw-r--r--drivers/video/fbdev/core/fbcon.c33
-rw-r--r--drivers/video/fbdev/core/fbmem.c16
-rw-r--r--include/linux/fbcon.h4
-rw-r--r--include/video/of_display_timing.h2
4 files changed, 53 insertions, 2 deletions
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index c4e91715ef00..1a9aa12cf886 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2469,6 +2469,11 @@ static int fbcon_set_font(struct vc_data *vc, struct console_font *font,
if (charcount != 256 && charcount != 512)
return -EINVAL;
+ /* font bigger than screen resolution ? */
+ if (w > FBCON_SWAP(info->var.rotate, info->var.xres, info->var.yres) ||
+ h > FBCON_SWAP(info->var.rotate, info->var.yres, info->var.xres))
+ return -EINVAL;
+
/* Make sure drawing engine can handle the font */
if (!(info->pixmap.blit_x & (1 << (font->width - 1))) ||
!(info->pixmap.blit_y & (1 << (font->height - 1))))
@@ -2731,6 +2736,34 @@ void fbcon_update_vcs(struct fb_info *info, bool all)
}
EXPORT_SYMBOL(fbcon_update_vcs);
+/* let fbcon check if it supports a new screen resolution */
+int fbcon_modechange_possible(struct fb_info *info, struct fb_var_screeninfo *var)
+{
+ struct fbcon_ops *ops = info->fbcon_par;
+ struct vc_data *vc;
+ unsigned int i;
+
+ WARN_CONSOLE_UNLOCKED();
+
+ if (!ops)
+ return 0;
+
+ /* prevent setting a screen size which is smaller than font size */
+ for (i = first_fb_vc; i <= last_fb_vc; i++) {
+ vc = vc_cons[i].d;
+ if (!vc || vc->vc_mode != KD_TEXT ||
+ fbcon_info_from_console(i) != info)
+ continue;
+
+ if (vc->vc_font.width > FBCON_SWAP(var->rotate, var->xres, var->yres) ||
+ vc->vc_font.height > FBCON_SWAP(var->rotate, var->yres, var->xres))
+ return -EINVAL;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fbcon_modechange_possible);
+
int fbcon_mode_deleted(struct fb_info *info,
struct fb_videomode *mode)
{
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 8afc4538558c..7ee6eb2fa715 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -511,7 +511,7 @@ static int fb_show_logo_line(struct fb_info *info, int rotate,
while (n && (n * (logo->width + 8) - 8 > xres))
--n;
- image.dx = (xres - n * (logo->width + 8) - 8) / 2;
+ image.dx = (xres - (n * (logo->width + 8) - 8)) / 2;
image.dy = y ?: (yres - logo->height) / 2;
} else {
image.dx = 0;
@@ -1017,6 +1017,16 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
if (ret)
return ret;
+ /* verify that virtual resolution >= physical resolution */
+ if (var->xres_virtual < var->xres ||
+ var->yres_virtual < var->yres) {
+ pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",
+ info->fix.id,
+ var->xres_virtual, var->yres_virtual,
+ var->xres, var->yres);
+ return -EINVAL;
+ }
+
if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
return 0;
@@ -1107,7 +1117,9 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
return -EFAULT;
console_lock();
lock_fb_info(info);
- ret = fb_set_var(info, &var);
+ ret = fbcon_modechange_possible(info, &var);
+ if (!ret)
+ ret = fb_set_var(info, &var);
if (!ret)
fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
unlock_fb_info(info);
diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h
index ff5596dd30f8..2382dec6d6ab 100644
--- a/include/linux/fbcon.h
+++ b/include/linux/fbcon.h
@@ -15,6 +15,8 @@ void fbcon_new_modelist(struct fb_info *info);
void fbcon_get_requirement(struct fb_info *info,
struct fb_blit_caps *caps);
void fbcon_fb_blanked(struct fb_info *info, int blank);
+int fbcon_modechange_possible(struct fb_info *info,
+ struct fb_var_screeninfo *var);
void fbcon_update_vcs(struct fb_info *info, bool all);
void fbcon_remap_all(struct fb_info *info);
int fbcon_set_con2fb_map_ioctl(void __user *argp);
@@ -33,6 +35,8 @@ static inline void fbcon_new_modelist(struct fb_info *info) {}
static inline void fbcon_get_requirement(struct fb_info *info,
struct fb_blit_caps *caps) {}
static inline void fbcon_fb_blanked(struct fb_info *info, int blank) {}
+static inline int fbcon_modechange_possible(struct fb_info *info,
+ struct fb_var_screeninfo *var) { return 0; }
static inline void fbcon_update_vcs(struct fb_info *info, bool all) {}
static inline void fbcon_remap_all(struct fb_info *info) {}
static inline int fbcon_set_con2fb_map_ioctl(void __user *argp) { return 0; }
diff --git a/include/video/of_display_timing.h b/include/video/of_display_timing.h
index e1126a74882a..eff166fdd81b 100644
--- a/include/video/of_display_timing.h
+++ b/include/video/of_display_timing.h
@@ -8,6 +8,8 @@
#ifndef __LINUX_OF_DISPLAY_TIMING_H
#define __LINUX_OF_DISPLAY_TIMING_H
+#include <linux/errno.h>
+
struct device_node;
struct display_timing;
struct display_timings;