{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-01T02:50:12.805","vulnerabilities":[{"cve":{"id":"CVE-2024-26798","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-04-04T09:15:08.897","lastModified":"2026-03-17T17:22:58.967","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbcon: always restore the old font data in fbcon_do_set_font()\n\nCommit a5a923038d70 (fbdev: fbcon: Properly revert changes when\nvc_resize() failed) started restoring old font data upon failure (of\nvc_resize()). But it performs so only for user fonts. It means that the\n\"system\"/internal fonts are not restored at all. So in result, the very\nfirst call to fbcon_do_set_font() performs no restore at all upon\nfailing vc_resize().\n\nThis can be reproduced by Syzkaller to crash the system on the next\ninvocation of font_get(). It's rather hard to hit the allocation failure\nin vc_resize() on the first font_set(), but not impossible. Esp. if\nfault injection is used to aid the execution/failure. It was\ndemonstrated by Sirius:\n  BUG: unable to handle page fault for address: fffffffffffffff8\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0\n  Oops: 0000 [#1] PREEMPT SMP KASAN\n  CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n  RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286\n  Call Trace:\n   <TASK>\n   con_font_get drivers/tty/vt/vt.c:4558 [inline]\n   con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673\n   vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]\n   vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752\n   tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803\n   vfs_ioctl fs/ioctl.c:51 [inline]\n  ...\n\nSo restore the font data in any case, not only for user fonts. Note the\nlater 'if' is now protected by 'old_userfont' and not 'old_data' as the\nlatter is always set now. (And it is supposed to be non-NULL. Otherwise\nwe would see the bug above again.)"},{"lang":"es","value":"En el kernel de Linux, se resolvió la siguiente vulnerabilidad: fbcon: restaurar siempre los datos de fuentes antiguos en fbcon_do_set_font() commit a5a923038d70 (fbdev: fbcon: revertir correctamente los cambios cuando falló vc_resize()) comenzó a restaurar los datos de fuentes antiguos en caso de falla (de vc_resize ()). Pero funciona sólo para fuentes de usuario. Significa que las fuentes internas/del \"SYSTEM\" no se restauran en absoluto. Entonces, como resultado, la primera llamada a fbcon_do_set_font() no realiza ninguna restauración al fallar vc_resize(). Syzkaller puede reproducir esto para bloquear el SYSTEM en la siguiente invocación de font_get(). Es bastante difícil solucionar el error de asignación en vc_resize() en el primer font_set(), pero no imposible. Esp. si se utiliza la inyección de fallos para ayudar en la ejecución/fallo. Sirius lo demostró: ERROR: no se puede manejar el error de página para la dirección: fffffffffffffff8 #PF: acceso de lectura del supervisor en modo kernel #PF: error_code(0x0000) - página no presente PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0 Ups: 0000 [ #1] PREEMPT SMP KASAN CPU: 1 PID: 8007 Comm: poc No contaminado 6.7.0-g9d1694dc91ce #20 Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.15.0-1 01/04/2014 RIP : 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286 Seguimiento de llamadas:  con_font_get drivers/tty/vt/vt.c:4558 [en línea] con_font_op+0x1fc/0xf20 drivers/tty /vt/vt.c:4673 controladores vt_k_ioctl/tty/vt/vt_ioctl.c:474 [en línea] vt_ioctl+0x632/0x2ec0 controladores/tty/vt/vt_ioctl.c:752 tty_ioctl+0x6f8/0x1570 controladores/tty/tty_io. c:2803 vfs_ioctl fs/ioctl.c:51 [en línea] ... Así que restaure los datos de fuente en cualquier caso, no solo para las fuentes del usuario. Tenga en cuenta que el 'if' posterior ahora está protegido por 'old_userfont' y no por 'old_data' ya que este último siempre está configurado ahora. (Y se supone que no es NULL. De lo contrario, volveríamos a ver el error anterior)."}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-770"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.64","versionEndExcluding":"5.15.151","matchCriteriaId":"C6852C0F-A534-43B3-BDC6-ECFEF26AB7DB"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1.81","matchCriteriaId":"89A51AC3-83B4-4F44-B496-385D10612456"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.21","matchCriteriaId":"B19074A2-9FE5-4E7D-9E2D-020F95013ADA"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.7.9","matchCriteriaId":"1C538467-EDA0-4A9A-82EB-2925DE9FF827"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*","matchCriteriaId":"B9F4EA73-0894-400F-A490-3A397AB7A517"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*","matchCriteriaId":"056BD938-0A27-4569-B391-30578B309EE3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*","matchCriteriaId":"F02056A5-B362-4370-9FF8-6F0BD384D520"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*","matchCriteriaId":"62075ACE-B2A0-4B16-829D-B3DA5AE5CC41"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*","matchCriteriaId":"A780F817-2A77-4130-A9B7-5C25606314E3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:*","matchCriteriaId":"AEB9199B-AB8F-4877-8964-E2BA95B5F15C"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/20a4b5214f7bee13c897477168c77bbf79683c3d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/2f91a96b892fab2f2543b4a55740c5bee36b1a6b","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/73a6bd68a1342f3a44cac9dffad81ad6a003e520","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/a2c881413dcc5d801bdc9535e51270cc88cb9cd8","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/ae68f57df3335679653868fafccd8c88ef84ae98","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/20a4b5214f7bee13c897477168c77bbf79683c3d","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/2f91a96b892fab2f2543b4a55740c5bee36b1a6b","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/73a6bd68a1342f3a44cac9dffad81ad6a003e520","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/a2c881413dcc5d801bdc9535e51270cc88cb9cd8","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]}]}}]}