Fixes for 5.4

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-5.4/fbmem-pull-fbcon_update_vcs-out-of-fb_set_var.patch b/queue-5.4/fbmem-pull-fbcon_update_vcs-out-of-fb_set_var.patch
new file mode 100644 (file)
index 0000000..e79681b
--- /dev/null
+++ b/queue-5.4/fbmem-pull-fbcon_update_vcs-out-of-fb_set_var.patch
@@ -0,0 +1,133 @@
+From b27d2654856458ea14c446a9d26008db4de640b1 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Thu, 30 Jul 2020 19:47:14 +0900
+Subject: fbmem: pull fbcon_update_vcs() out of fb_set_var()
+
+From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
+
+[ Upstream commit d88ca7e1a27eb2df056bbf37ddef62e1c73d37ea ]
+
+syzbot is reporting OOB read bug in vc_do_resize() [1] caused by memcpy()
+based on outdated old_{rows,row_size} values, for resize_screen() can
+recurse into vc_do_resize() which changes vc->vc_{cols,rows} that outdates
+old_{rows,row_size} values which were saved before calling resize_screen().
+
+Daniel Vetter explained that resize_screen() should not recurse into
+fbcon_update_vcs() path due to FBINFO_MISC_USEREVENT being still set
+when calling resize_screen().
+
+Instead of masking FBINFO_MISC_USEREVENT before calling fbcon_update_vcs(),
+we can remove FBINFO_MISC_USEREVENT by calling fbcon_update_vcs() only if
+fb_set_var() returned 0. This change assumes that it is harmless to call
+fbcon_update_vcs() when fb_set_var() returned 0 without reaching
+fb_notifier_call_chain().
+
+[1] https://syzkaller.appspot.com/bug?id=c70c88cfd16dcf6e1d3c7f0ab8648b3144b5b25e
+
+Reported-and-tested-by: syzbot <syzbot+c37a14770d51a085a520@syzkaller.appspotmail.com>
+Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
+Reported-by: kernel test robot <lkp@intel.com> for missing #include
+Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+Link: https://patchwork.freedesktop.org/patch/msgid/075b7e37-3278-cd7d-31ab-c5073cfa8e92@i-love.sakura.ne.jp
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/video/fbdev/core/fbmem.c   | 8 ++------
+ drivers/video/fbdev/core/fbsysfs.c | 4 ++--
+ drivers/video/fbdev/ps3fb.c        | 5 +++--
+ include/linux/fb.h                 | 2 --
+ 4 files changed, 7 insertions(+), 12 deletions(-)
+
+diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
+index e72738371ecbe..97abcd497c7e0 100644
+--- a/drivers/video/fbdev/core/fbmem.c
++++ b/drivers/video/fbdev/core/fbmem.c
+@@ -952,7 +952,6 @@ static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
+ int
+ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
+ {
+-      int flags = info->flags;
+       int ret = 0;
+       u32 activate;
+       struct fb_var_screeninfo old_var;
+@@ -1047,9 +1046,6 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
+       event.data = &mode;
+       fb_notifier_call_chain(FB_EVENT_MODE_CHANGE, &event);
+ 
+-      if (flags & FBINFO_MISC_USEREVENT)
+-              fbcon_update_vcs(info, activate & FB_ACTIVATE_ALL);
+-
+       return 0;
+ }
+ EXPORT_SYMBOL(fb_set_var);
+@@ -1100,9 +1096,9 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
+                       return -EFAULT;
+               console_lock();
+               lock_fb_info(info);
+-              info->flags |= FBINFO_MISC_USEREVENT;
+               ret = fb_set_var(info, &var);
+-              info->flags &= ~FBINFO_MISC_USEREVENT;
++              if (!ret)
++                      fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
+               unlock_fb_info(info);
+               console_unlock();
+               if (!ret && copy_to_user(argp, &var, sizeof(var)))
+diff --git a/drivers/video/fbdev/core/fbsysfs.c b/drivers/video/fbdev/core/fbsysfs.c
+index d54c88f88991d..65dae05fff8e6 100644
+--- a/drivers/video/fbdev/core/fbsysfs.c
++++ b/drivers/video/fbdev/core/fbsysfs.c
+@@ -91,9 +91,9 @@ static int activate(struct fb_info *fb_info, struct fb_var_screeninfo *var)
+ 
+       var->activate |= FB_ACTIVATE_FORCE;
+       console_lock();
+-      fb_info->flags |= FBINFO_MISC_USEREVENT;
+       err = fb_set_var(fb_info, var);
+-      fb_info->flags &= ~FBINFO_MISC_USEREVENT;
++      if (!err)
++              fbcon_update_vcs(fb_info, var->activate & FB_ACTIVATE_ALL);
+       console_unlock();
+       if (err)
+               return err;
+diff --git a/drivers/video/fbdev/ps3fb.c b/drivers/video/fbdev/ps3fb.c
+index 5ed2db39d8236..ce90483c50209 100644
+--- a/drivers/video/fbdev/ps3fb.c
++++ b/drivers/video/fbdev/ps3fb.c
+@@ -29,6 +29,7 @@
+ #include <linux/freezer.h>
+ #include <linux/uaccess.h>
+ #include <linux/fb.h>
++#include <linux/fbcon.h>
+ #include <linux/init.h>
+ 
+ #include <asm/cell-regs.h>
+@@ -824,12 +825,12 @@ static int ps3fb_ioctl(struct fb_info *info, unsigned int cmd,
+                               var = info->var;
+                               fb_videomode_to_var(&var, vmode);
+                               console_lock();
+-                              info->flags |= FBINFO_MISC_USEREVENT;
+                               /* Force, in case only special bits changed */
+                               var.activate |= FB_ACTIVATE_FORCE;
+                               par->new_mode_id = val;
+                               retval = fb_set_var(info, &var);
+-                              info->flags &= ~FBINFO_MISC_USEREVENT;
++                              if (!retval)
++                                      fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
+                               console_unlock();
+                       }
+                       break;
+diff --git a/include/linux/fb.h b/include/linux/fb.h
+index 756706b666a10..8221838fefd98 100644
+--- a/include/linux/fb.h
++++ b/include/linux/fb.h
+@@ -400,8 +400,6 @@ struct fb_tile_ops {
+ #define FBINFO_HWACCEL_YPAN           0x2000 /* optional */
+ #define FBINFO_HWACCEL_YWRAP          0x4000 /* optional */
+ 
+-#define FBINFO_MISC_USEREVENT          0x10000 /* event request
+-                                                from userspace */
+ #define FBINFO_MISC_TILEBLITTING       0x20000 /* use tile blitting */
+ 
+ /* A driver may set this flag to indicate that it does want a set_par to be
+-- 
+2.25.1
+

diff --git a/queue-5.4/series b/queue-5.4/series
index 1eed5c6b089238579805261b043fdc33b0695f9a..c9f38f286ff69019421635bd97c605c2ec334410 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -201,3 +201,4 @@ drm-i915-fix-cmd-parser-desc-matching-with-masks.patch
 usb-dwc3-gadget-don-t-setup-more-than-requested.patch
 usb-dwc3-gadget-fix-handling-zlp.patch
 usb-dwc3-gadget-handle-zlp-for-sg-requests.patch
+fbmem-pull-fbcon_update_vcs-out-of-fb_set_var.patch