[SRU F/OEM-5.14/J/OEM-5.17 PATCH 0/3] CVE-2021-33655

Cengiz Can cengiz.can at canonical.com
Fri Aug 5 10:09:40 UTC 2022

When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,
kernel will write memory out of bounds.

Fixes were cherry-picked from closest stable trees and upstream.

MITRE entry points to a merge commit that contain six patches. Three of
those were considered relevant.

[Test case]
Compile and boot tested on KVM only.

[Potential regression]
Due to self contained changes on >5.4, seems minimal.

Helge Deller (3):
  fbcon: Disallow setting font bigger than screen size
  fbcon: Prevent that screen size is smaller than font size
  fbmem: Check virtual screen sizes in fb_set_var()

 drivers/video/fbdev/core/fbcon.c | 33 ++++++++++++++++++++++++++++++++
 drivers/video/fbdev/core/fbmem.c | 14 +++++++++++++-
 include/linux/fbcon.h            |  4 ++++
 3 files changed, 50 insertions(+), 1 deletion(-)


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