{"cve":"CVE-2024-26798","nvd":{"published":"2024-04-04T09:15:08.897","modified":"2026-06-17T07:18:22.460","status":"Analyzed","description":"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.)","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-770"],"references":["https://git.kernel.org/stable/c/00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f","https://git.kernel.org/stable/c/20a4b5214f7bee13c897477168c77bbf79683c3d","https://git.kernel.org/stable/c/2f91a96b892fab2f2543b4a55740c5bee36b1a6b","https://git.kernel.org/stable/c/73a6bd68a1342f3a44cac9dffad81ad6a003e520","https://git.kernel.org/stable/c/a2c881413dcc5d801bdc9535e51270cc88cb9cd8"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:48:32.179249784+00:00"},"epss":{"cve":"CVE-2024-26798","score":0.00327,"percentile":0.25798,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}