From: Sasha Levin Date: Tue, 1 Sep 2020 03:02:45 +0000 (-0400) Subject: Fixes for 5.4 X-Git-Tag: v4.4.235~20 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d7e3412b07fbbb0095e59786404bcee7f12c9529;p=thirdparty%2Fkernel%2Fstable-queue.git Fixes for 5.4 Signed-off-by: Sasha Levin --- 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 index 00000000000..e79681b6129 --- /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 +Date: Thu, 30 Jul 2020 19:47:14 +0900 +Subject: fbmem: pull fbcon_update_vcs() out of fb_set_var() + +From: Tetsuo Handa + +[ 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] + +syzbot is reporting OOB read bug in vc_do_resize() [1] caused by memcpy() +based on outdated old_{rows,row_size} values, for resize_screen() can +recurse into vc_do_resize() which changes vc-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 +Suggested-by: Daniel Vetter +Signed-off-by: Tetsuo Handa +Reported-by: kernel test robot for missing #include +Signed-off-by: Daniel Vetter +Link: https://patchwork.freedesktop.org/patch/msgid/075b7e37-3278-cd7d-31ab-c5073cfa8e92@i-love.sakura.ne.jp +Signed-off-by: Sasha Levin +--- + 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 + #include + #include ++#include + #include + + #include +@@ -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 1eed5c6b089..c9f38f286ff 100644 --- 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