CVE-2023-54198
Unknown Unknown - Not Provided
Out-of-Bounds Access in Linux tty_driver Causes Kernel Crash

Publication date: 2025-12-30

Last updated on: 2025-12-30

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: tty: fix out-of-bounds access in tty_driver_lookup_tty() When specifying an invalid console= device like console=tty3270, tty_driver_lookup_tty() returns the tty struct without checking whether index is a valid number. To reproduce: qemu-system-x86_64 -enable-kvm -nographic -serial mon:stdio \ -kernel ../linux-build-x86/arch/x86/boot/bzImage \ -append "console=ttyS0 console=tty3270" This crashes with: [ 0.770599] BUG: kernel NULL pointer dereference, address: 00000000000000ef [ 0.771265] #PF: supervisor read access in kernel mode [ 0.771773] #PF: error_code(0x0000) - not-present page [ 0.772609] Oops: 0000 [#1] PREEMPT SMP PTI [ 0.774878] RIP: 0010:tty_open+0x268/0x6f0 [ 0.784013] chrdev_open+0xbd/0x230 [ 0.784444] ? cdev_device_add+0x80/0x80 [ 0.784920] do_dentry_open+0x1e0/0x410 [ 0.785389] path_openat+0xca9/0x1050 [ 0.785813] do_filp_open+0xaa/0x150 [ 0.786240] file_open_name+0x133/0x1b0 [ 0.786746] filp_open+0x27/0x50 [ 0.787244] console_on_rootfs+0x14/0x4d [ 0.787800] kernel_init_freeable+0x1e4/0x20d [ 0.788383] ? rest_init+0xc0/0xc0 [ 0.788881] kernel_init+0x11/0x120 [ 0.789356] ret_from_fork+0x22/0x30
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Meta Information
Published
2025-12-30
Last Modified
2025-12-30
Generated
2026-06-16
AI Q&A
2025-12-30
EPSS Evaluated
2026-06-15
NVD
CVE-2023-54198
EUVD
EUVD-2023-60443
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability is an out-of-bounds access issue in the Linux kernel function tty_driver_lookup_tty(). When an invalid console device is specified (for example, console=tty3270), the function returns a tty struct without verifying if the index is valid. This can lead to a kernel crash due to a NULL pointer dereference.

Impact Analysis

The vulnerability can cause the Linux kernel to crash (kernel panic) when an invalid console device is specified. This can lead to denial of service as the system becomes unstable or unusable until rebooted.

Detection Guidance

This vulnerability can be detected by checking for kernel crash logs indicating a NULL pointer dereference related to tty_driver_lookup_tty(), especially after specifying invalid console= devices like console=tty3270. You can look for kernel oops messages in system logs using commands such as 'dmesg | grep -i tty' or 'journalctl -k | grep -i tty'. Additionally, reproducing the issue with a command similar to the provided example using qemu can help confirm the vulnerability: qemu-system-x86_64 -enable-kvm -nographic -serial mon:stdio -kernel <kernel_image> -append "console=ttyS0 console=tty3270"

Mitigation Strategies

Immediate mitigation involves avoiding the use of invalid console= device parameters such as console=tty3270 when booting the Linux kernel. Applying the kernel update or patch that fixes the out-of-bounds access in tty_driver_lookup_tty() is necessary to fully resolve the issue.

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