{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.113-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.10-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  vt: skip screen update for DEC alignment test on backgroup consoles  [BUG] Recently, we encountered a KASAN warning as follows:  BUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x11f/0x140 Read of size 1 at addr ff1100015fd9f6a4 by task tty_fbcon_oob/1239 CPU: 7 UID: 0 PID: 1239 Comm: tty_fbcon_oob Not tainted 7.3.0-rc1 #100 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 Call Trace:  \u003cTASK\u003e  ...  kasan_report+0xf0/0x120  fb_pad_aligned_buffer+0x11f/0x140  ccw_putcs+0x86c/0xa80  fbcon_putcs+0x338/0x410  do_update_region+0x21d/0x450  do_con_write+0x1e0e/0x4880  con_write+0x13/0x80  n_tty_write+0x374/0x1010  file_tty_write.isra.0+0x404/0x7a0  ...  reproduce: 1) open /dev/tty0, set a KDFONTOP ioctl with op.op = KD_FONT_OP_SET, op.width = 8 and op.height = 16 (visible VC1) 2) open /dev/tty1, set a KDFONTOP ioctl with op.op = KD_FONT_OP_SET, op.width = 28 and op.height = 24 (invisible VC2) 3) echo 3 \u003e /sys/devices/virtual/graphics/fbcon/rotate_all 4) write EShash8(esc hash8) to tty1  [CAUSE] All VCs render to the framebuffer. setfont only modifies the target VC's font without resizing the framebuffer backing buffer (par-\u003erotated.buf); the buffer is only resized for the visible VC (fbcon_do_set_font -\u003e ... -\u003e vc_do_resize -\u003e update_screen). This relies on the con_should_update() check performed before every update_region().  However, the ESC # 8 path (do_con_trol -\u003e do_update_region) omits the con_should_update() check. After changing the font size of an invisible VC, do_update_region() fills using the new font size against a buffer that was never resized, causing an out-of-bounds access.  [FIX] Only push the update when the console is visible and not blanked, add the con_should_update() check in the do_con_trol() like every other call site of do_update_region() (update_region(), invert_screen(), ...).",
  "id": "DEBIAN-CVE-2026-98838",
  "modified": "2026-10-19T04:47:35.335691652Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98838"
    }
  ],
  "upstream": [
    "CVE-2026-98838"
  ]
}