{"id":"CVE-2024-50048","summary":"fbcon: Fix a NULL pointer dereference issue in fbcon_putcs","details":"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  -\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.","modified":"2026-04-02T12:21:14.909Z","published":"2024-10-21T19:39:45.146Z","related":["MGASA-2024-0344","MGASA-2024-0345","SUSE-SU-2024:3983-1","SUSE-SU-2024:3984-1","SUSE-SU-2024:3985-1","SUSE-SU-2024:3986-1","SUSE-SU-2024:4318-1","SUSE-SU-2024:4364-1","SUSE-SU-2024:4387-1","SUSE-SU-2025:20163-1","SUSE-SU-2025:20164-1","SUSE-SU-2025:20246-1","SUSE-SU-2025:20247-1","USN-7276-1","USN-7277-1","openSUSE-SU-2024:14500-1","openSUSE-SU-2025:14705-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50048.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5b97eebcce1b4f3f07a71f635d6aa3af96c236e7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8266ae6eafdcd5a3136592445ff4038bbc7ee80e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e5c2dba62996a3a6eeb34bd248b90fc69c5a6a1b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f7fb5dda555344529ce584ff7a28b109528d2f1b"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50048.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-50048"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b07db39584856e16814e2f065380e533a001535d"},{"fixed":"8266ae6eafdcd5a3136592445ff4038bbc7ee80e"},{"fixed":"f7fb5dda555344529ce584ff7a28b109528d2f1b"},{"fixed":"e5c2dba62996a3a6eeb34bd248b90fc69c5a6a1b"},{"fixed":"5b97eebcce1b4f3f07a71f635d6aa3af96c236e7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-50048.json"}}],"schema_version":"1.7.5"}