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,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "05D83DB8-7465-4F88-AFB2-980011992AC1",
                     versionEndExcluding: "6.6.57",
                     versionStartIncluding: "6.2",
                     vulnerable: true,
                  },
                  {
                     criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                     matchCriteriaId: "AA84D336-CE9A-4535-B901-1AD77EC17C34",
                     versionEndExcluding: "6.11.4",
                     versionStartIncluding: "6.7",
                     vulnerable: true,
                  },
               ],
               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, &con2fb);\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, &param);\n\n\tcon2fb.console = 1;\n\tcon2fb.framebuffer = 0;\n\tioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);\n\n\treturn 0;\n}\n\nAfter calling ioctl(fd1, TIOCLINUX, &param), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb)\ncauses the kernel to follow a different execution path:\n\n set_con2fb_map\n  -> con2fb_init_display\n   -> fbcon_set_disp\n    -> redraw_screen\n     -> hide_cursor\n      -> clear_selection\n       -> highlight\n        -> invert_screen\n         -> do_update_region\n          -> fbcon_putcs\n           -> ops->putcs\n\nSince ops->putcs 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->putcs.",
      },
      {
         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. Aquí está 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, &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); devolver 0; } Después de llamar a ioctl(fd1, TIOCLINUX, &param), el ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb) subsiguiente hace que el núcleo siga una ruta de ejecución diferente: 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 Dado que ops->putcs es un puntero NULL, esto lleva a un pánico del núcleo. Para evitar esto, necesitamos llamar a set_blitting_type() dentro de set_con2fb_map() para inicializar correctamente ops->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",
         ],
         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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