+++ /dev/null
-From foo@baz Sun Jul 31 01:15:12 PM CEST 2022
-From: Chen Jun <chenjun102@huawei.com>
-Date: Fri, 29 Jul 2022 03:11:39 +0000
-Subject: fbcon: Prevent that screen size is smaller than font size
-To: <stable@vger.kernel.org>, <deller@gmx.de>, <geert@linux-m68k.org>, <b.zolnierkie@samsung.com>, <gregkh@linuxfoundation.org>
-Cc: <xuqiang36@huawei.com>, <xiujianfeng@huawei.com>
-Message-ID: <20220729031140.21806-2-chenjun102@huawei.com>
-
-From: Helge Deller <deller@gmx.de>
-
-commit e64242caef18b4a5840b0e7a9bff37abd4f4f933 upstream
-
-We need to prevent that users configure a screen size which is smaller than the
-currently selected font size. Otherwise rendering chars on the screen will
-access memory outside the graphics memory region.
-
-This patch adds a new function fbcon_modechange_possible() which
-implements this check and which later may be extended with other checks
-if necessary. The new function is called from the FBIOPUT_VSCREENINFO
-ioctl handler in fbmem.c, which will return -EINVAL if userspace asked
-for a too small screen size.
-
-Signed-off-by: Helge Deller <deller@gmx.de>
-Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
-Link: https://lore.kernel.org/all/20220706150253.2186-1-deller@gmx.de/
-[sudip: adjust context]
-Signed-off-by: Chen Jun <chenjun102@huawei.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- drivers/video/fbdev/core/fbcon.c | 28 ++++++++++++++++++++++++++++
- drivers/video/fbdev/core/fbmem.c | 10 +++++++---
- include/linux/fbcon.h | 4 ++++
- 3 files changed, 39 insertions(+), 3 deletions(-)
-
---- a/drivers/video/fbdev/core/fbcon.c
-+++ b/drivers/video/fbdev/core/fbcon.c
-@@ -2706,6 +2706,34 @@ static void fbcon_set_all_vcs(struct fb_
- fbcon_modechanged(info);
- }
-
-+/* 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 ||
-+ registered_fb[con2fb_map[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);
-+
- static int fbcon_mode_deleted(struct fb_info *info,
- struct fb_videomode *mode)
- {
---- a/drivers/video/fbdev/core/fbmem.c
-+++ b/drivers/video/fbdev/core/fbmem.c
-@@ -1134,9 +1134,13 @@ static long do_fb_ioctl(struct fb_info *
- console_unlock();
- return -ENODEV;
- }
-- info->flags |= FBINFO_MISC_USEREVENT;
-- ret = fb_set_var(info, &var);
-- info->flags &= ~FBINFO_MISC_USEREVENT;
-+ ret = fbcon_modechange_possible(info, &var);
-+ if (!ret) {
-+ info->flags |= FBINFO_MISC_USEREVENT;
-+ ret = fb_set_var(info, &var);
-+ info->flags &= ~FBINFO_MISC_USEREVENT;
-+ }
-+ lock_fb_info(info);
- unlock_fb_info(info);
- console_unlock();
- if (!ret && copy_to_user(argp, &var, sizeof(var)))
---- a/include/linux/fbcon.h
-+++ b/include/linux/fbcon.h
-@@ -4,9 +4,13 @@
- #ifdef CONFIG_FRAMEBUFFER_CONSOLE
- void __init fb_console_init(void);
- void __exit fb_console_exit(void);
-+int fbcon_modechange_possible(struct fb_info *info,
-+ struct fb_var_screeninfo *var);
- #else
- static inline void fb_console_init(void) {}
- static inline void fb_console_exit(void) {}
-+static inline int fbcon_modechange_possible(struct fb_info *info,
-+ struct fb_var_screeninfo *var) { return 0; }
- #endif
-
- #endif /* _LINUX_FBCON_H */
+++ /dev/null
-From foo@baz Sun Jul 31 01:15:12 PM CEST 2022
-From: Chen Jun <chenjun102@huawei.com>
-Date: Fri, 29 Jul 2022 03:11:40 +0000
-Subject: fbmem: Check virtual screen sizes in fb_set_var()
-To: <stable@vger.kernel.org>, <deller@gmx.de>, <geert@linux-m68k.org>, <b.zolnierkie@samsung.com>, <gregkh@linuxfoundation.org>
-Cc: <xuqiang36@huawei.com>, <xiujianfeng@huawei.com>
-Message-ID: <20220729031140.21806-3-chenjun102@huawei.com>
-
-From: Helge Deller <deller@gmx.de>
-
-commit 6c11df58fd1ac0aefcb3b227f72769272b939e56 upstream
-
-Verify that the fbdev or drm driver correctly adjusted the virtual
-screen sizes. On failure report the failing driver and reject the screen
-size change.
-
-Signed-off-by: Helge Deller <deller@gmx.de>
-Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
-Link: https://lore.kernel.org/all/20220706150253.2186-1-deller@gmx.de/
-[sudip: adjust context]
-Signed-off-by: Chen Jun <chenjun102@huawei.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- drivers/video/fbdev/core/fbmem.c | 10 ++++++++++
- 1 file changed, 10 insertions(+)
-
---- a/drivers/video/fbdev/core/fbmem.c
-+++ b/drivers/video/fbdev/core/fbmem.c
-@@ -1019,6 +1019,16 @@ fb_set_var(struct fb_info *info, struct
- if (ret)
- goto done;
-
-+ /* 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) {
- struct fb_var_screeninfo old_var;
- struct fb_videomode mode;
projects / thirdparty / kernel / stable-queue.git / commitdiff
