fkie_cve-2024-50048
Vulnerability from fkie_nvd
Published
2024-10-21 20:15
Modified
2024-10-23 21:46
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: fbcon: Fix a NULL pointer dereference issue in fbcon_putcs syzbot has found a NULL pointer dereference bug in fbcon. Here is the simplified C reproducer: struct param { uint8_t type; struct tiocl_selection ts; }; int main() { struct fb_con2fbmap con2fb; struct param param; int fd = open("/dev/fb1", 0, 0); con2fb.console = 0x19; con2fb.framebuffer = 0; ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb); param.type = 2; param.ts.xs = 0; param.ts.ys = 0; param.ts.xe = 0; param.ts.ye = 0; param.ts.sel_mode = 0; int fd1 = open("/dev/tty1", O_RDWR, 0); ioctl(fd1, TIOCLINUX, &param); con2fb.console = 1; con2fb.framebuffer = 0; ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb); return 0; } After calling ioctl(fd1, TIOCLINUX, &param), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb) causes the kernel to follow a different execution path: set_con2fb_map -> con2fb_init_display -> fbcon_set_disp -> redraw_screen -> hide_cursor -> clear_selection -> highlight -> invert_screen -> do_update_region -> fbcon_putcs -> ops->putcs Since ops->putcs is a NULL pointer, this leads to a kernel panic. To prevent this, we need to call set_blitting_type() within set_con2fb_map() to properly initialize ops->putcs.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5b97eebcce1b4f3f07a71f635d6aa3af96c236e7Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8266ae6eafdcd5a3136592445ff4038bbc7ee80ePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e5c2dba62996a3a6eeb34bd248b90fc69c5a6a1bPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f7fb5dda555344529ce584ff7a28b109528d2f1bPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *


To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "180292D6-C3A4-4883-98A3-77F4D56F8081",
              "versionEndExcluding": "6.1.113",
              "vulnerable": true
            },
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              "versionEndExcluding": "6.6.57",
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              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              "versionEndExcluding": "6.11.4",
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            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbcon: Fix a NULL pointer dereference issue in fbcon_putcs\n\nsyzbot has found a NULL pointer dereference bug in fbcon.\nHere is the simplified C reproducer:\n\nstruct param {\n\tuint8_t type;\n\tstruct tiocl_selection ts;\n};\n\nint main()\n{\n\tstruct fb_con2fbmap con2fb;\n\tstruct param param;\n\n\tint fd = open(\"/dev/fb1\", 0, 0);\n\n\tcon2fb.console = 0x19;\n\tcon2fb.framebuffer = 0;\n\tioctl(fd, FBIOPUT_CON2FBMAP, \u0026con2fb);\n\n\tparam.type = 2;\n\tparam.ts.xs = 0; param.ts.ys = 0;\n\tparam.ts.xe = 0; param.ts.ye = 0;\n\tparam.ts.sel_mode = 0;\n\n\tint fd1 = open(\"/dev/tty1\", O_RDWR, 0);\n\tioctl(fd1, TIOCLINUX, \u0026param);\n\n\tcon2fb.console = 1;\n\tcon2fb.framebuffer = 0;\n\tioctl(fd, FBIOPUT_CON2FBMAP, \u0026con2fb);\n\n\treturn 0;\n}\n\nAfter calling ioctl(fd1, TIOCLINUX, \u0026param), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, \u0026con2fb)\ncauses the kernel to follow a different execution path:\n\n set_con2fb_map\n  -\u003e con2fb_init_display\n   -\u003e fbcon_set_disp\n    -\u003e redraw_screen\n     -\u003e hide_cursor\n      -\u003e clear_selection\n       -\u003e highlight\n        -\u003e invert_screen\n         -\u003e do_update_region\n          -\u003e fbcon_putcs\n           -\u003e ops-\u003eputcs\n\nSince ops-\u003eputcs is a NULL pointer, this leads to a kernel panic.\nTo prevent this, we need to call set_blitting_type() within set_con2fb_map()\nto properly initialize ops-\u003eputcs."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fbcon: soluciona un problema de desreferencia de puntero NULL en fbcon_putcs syzbot ha encontrado un error de desreferencia de puntero NULL en fbcon. Aqu\u00ed est\u00e1 el reproductor C simplificado: struct param { uint8_t type; struct tiocl_selection ts; }; int main() { struct fb_con2fbmap con2fb; struct param param; int fd = open(\"/dev/fb1\", 0, 0); con2fb.console = 0x19; con2fb.framebuffer = 0; ioctl(fd, FBIOPUT_CON2FBMAP, \u0026amp;con2fb); param.type = 2; param.ts.xs = 0; param.ts.ys = 0; param.ts.xe = 0; param.ts.ye = 0; param.ts.sel_mode = 0; int fd1 = open(\"/dev/tty1\", O_RDWR, 0); ioctl(fd1, TIOCLINUX, \u0026amp;param); con2fb.console = 1; con2fb.framebuffer = 0; ioctl(fd, FBIOPUT_CON2FBMAP, \u0026amp;con2fb); devolver 0; } Despu\u00e9s de llamar a ioctl(fd1, TIOCLINUX, \u0026amp;param), el ioctl(fd, FBIOPUT_CON2FBMAP, \u0026amp;con2fb) subsiguiente hace que el n\u00facleo siga una ruta de ejecuci\u00f3n diferente: set_con2fb_map -\u0026gt; con2fb_init_display -\u0026gt; fbcon_set_disp -\u0026gt; redraw_screen -\u0026gt; hide_cursor -\u0026gt; clear_selection -\u0026gt; highlight -\u0026gt; invert_screen -\u0026gt; do_update_region -\u0026gt; fbcon_putcs -\u0026gt; ops-\u0026gt;putcs Dado que ops-\u0026gt;putcs es un puntero NULL, esto lleva a un p\u00e1nico del n\u00facleo. Para evitar esto, necesitamos llamar a set_blitting_type() dentro de set_con2fb_map() para inicializar correctamente ops-\u0026gt;putcs."
    }
  ],
  "id": "CVE-2024-50048",
  "lastModified": "2024-10-23T21:46:11.533",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2024-10-21T20:15:17.580",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/5b97eebcce1b4f3f07a71f635d6aa3af96c236e7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/8266ae6eafdcd5a3136592445ff4038bbc7ee80e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/e5c2dba62996a3a6eeb34bd248b90fc69c5a6a1b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f7fb5dda555344529ce584ff7a28b109528d2f1b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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