cbcvebase.
CVE-2024-50048
published 2024-10-21

CVE-2024-50048: 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…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.25%
16.1th percentile
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, ¶m); con2fb.console = 1; con2fb.framebuffer = 0; ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb); return 0; } After calling ioctl(fd1, TIOCLINUX, ¶m), 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.

Affected

22 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.115-1 (bookworm)linux 6.1.115-1 (bookworm)
debianlinux-6.1< linux 6.1.115-1 (bookworm)linux 6.1.115-1 (bookworm)
linuxlinux
linuxlinux>= b07db39584856e16814e2f065380e533a001535d < 8266ae6eafdcd5a3136592445ff4038bbc7ee80e8266ae6eafdcd5a3136592445ff4038bbc7ee80e
linuxlinux>= b07db39584856e16814e2f065380e533a001535d < f7fb5dda555344529ce584ff7a28b109528d2f1bf7fb5dda555344529ce584ff7a28b109528d2f1b
linuxlinux>= b07db39584856e16814e2f065380e533a001535d < e5c2dba62996a3a6eeb34bd248b90fc69c5a6a1be5c2dba62996a3a6eeb34bd248b90fc69c5a6a1b
linuxlinux>= b07db39584856e16814e2f065380e533a001535d < 5b97eebcce1b4f3f07a71f635d6aa3af96c236e75b97eebcce1b4f3f07a71f635d6aa3af96c236e7
linuxlinux_kernel< 6.1.1136.1.113
linuxlinux_kernel>= 0 < 6.1.115-16.1.115-1
linuxlinux_kernel>= 0 < 6.11.4-16.11.4-1
linuxlinux_kernel>= 0 < 6.11.4-16.11.4-1
linuxlinux_kernel>= 0 < 6.8.0-56.586.8.0-56.58
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 6.2 < 6.6.576.6.57
linuxlinux_kernel>= 6.7 < 6.11.46.11.4
msrcazl3_kernel_6.6.56.1-5_on_azure_linux_3.0
msrcazl3_kernel_6.6.57.1-1_on_azure_linux_3.0
msrcazure_linux_3.0_arm
msrcazure_linux_3.0_x64
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.