CVE-2024-50048
MediumIn 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.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-476CVE-2024-50048 is a NULL Pointer Dereference vulnerability
What is NULL Pointer Dereference?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.19
and later are affected. Fixed in
6.1.113,
6.6.57,
6.11.4,
6.12
and their respective stable series.
References
The following references provide additional information about CVE-2024-50048 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/5b97eebcce1b4f3f07a71f635d6aa3af96c236e7
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PatchKernel patch commithttps://git.kernel.org/stable/c/8266ae6eafdcd5a3136592445ff4038bbc7ee80e
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PatchKernel patch commithttps://git.kernel.org/stable/c/e5c2dba62996a3a6eeb34bd248b90fc69c5a6a1b
Frequently asked questions
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What is CVE-2024-50048?
CVE-2024-50048 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.19 onward and has been patched in 6.1.113, 6.6.57, 6.11.4 and others. CVE-2024-50048 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2024-50048?
CVE-2024-50048 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2024-50048?
Yes — CVE-2024-50048 has been patched. Fixed versions include 6.1.113, 6.6.57, 6.11.4 and others. If you are running Linux kernel 5.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2024-50048 actively exploited?
No — CVE-2024-50048 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is NULL Pointer Dereference (CWE-476)?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →