Bug 2320772 (CVE-2022-48993) - CVE-2022-48993 kernel: fbcon: Use kzalloc() in fbcon_prepare_logo()
Summary: CVE-2022-48993 kernel: fbcon: Use kzalloc() in fbcon_prepare_logo()
Keywords:
Status: NEW
Alias: CVE-2022-48993
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-10-21 22:03 UTC by OSIDB Bzimport
Modified: 2024-10-22 05:54 UTC (History)
4 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2024-10-21 22:03:17 UTC
In the Linux kernel, the following vulnerability has been resolved:

fbcon: Use kzalloc() in fbcon_prepare_logo()

A kernel built with syzbot's config file reported that

  scr_memcpyw(q, save, array3_size(logo_lines, new_cols, 2))

causes uninitialized "save" to be copied.

  ----------
  [drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0
  [drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1
  Console: switching to colour frame buffer device 128x48
  =====================================================
  BUG: KMSAN: uninit-value in do_update_region+0x4b8/0xba0
   do_update_region+0x4b8/0xba0
   update_region+0x40d/0x840
   fbcon_switch+0x3364/0x35e0
   redraw_screen+0xae3/0x18a0
   do_bind_con_driver+0x1cb3/0x1df0
   do_take_over_console+0x11cb/0x13f0
   fbcon_fb_registered+0xacc/0xfd0
   register_framebuffer+0x1179/0x1320
   __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
   drm_fbdev_client_hotplug+0xbea/0xda0
   drm_fbdev_generic_setup+0x65e/0x9d0
   vkms_init+0x9f3/0xc76
   (...snipped...)

  Uninit was stored to memory at:
   fbcon_prepare_logo+0x143b/0x1940
   fbcon_init+0x2c1b/0x31c0
   visual_init+0x3e7/0x820
   do_bind_con_driver+0x14a4/0x1df0
   do_take_over_console+0x11cb/0x13f0
   fbcon_fb_registered+0xacc/0xfd0
   register_framebuffer+0x1179/0x1320
   __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
   drm_fbdev_client_hotplug+0xbea/0xda0
   drm_fbdev_generic_setup+0x65e/0x9d0
   vkms_init+0x9f3/0xc76
   (...snipped...)

  Uninit was created at:
   __kmem_cache_alloc_node+0xb69/0x1020
   __kmalloc+0x379/0x680
   fbcon_prepare_logo+0x704/0x1940
   fbcon_init+0x2c1b/0x31c0
   visual_init+0x3e7/0x820
   do_bind_con_driver+0x14a4/0x1df0
   do_take_over_console+0x11cb/0x13f0
   fbcon_fb_registered+0xacc/0xfd0
   register_framebuffer+0x1179/0x1320
   __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40
   drm_fbdev_client_hotplug+0xbea/0xda0
   drm_fbdev_generic_setup+0x65e/0x9d0
   vkms_init+0x9f3/0xc76
   (...snipped...)

  CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc4-00356-g8f2975c2bb4c #924
  Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
  ----------

Comment 1 Avinash Hanwate 2024-10-22 05:50:54 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102149-CVE-2022-48993-8b27@gregkh/T


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