CVE-2023-53481
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-01

Last updated on: 2025-10-02

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed Following process will trigger an infinite loop in ubi_wl_put_peb(): ubifs_bgt ubi_bgt ubifs_leb_unmap ubi_leb_unmap ubi_eba_unmap_leb ubi_wl_put_peb wear_leveling_worker e1 = rb_entry(rb_first(&ubi->used) e2 = get_peb_for_wl(ubi) ubi_io_read_vid_hdr // return err (flash fault) out_error: ubi->move_from = ubi->move_to = NULL wl_entry_destroy(ubi, e1) ubi->lookuptbl[e->pnum] = NULL retry: e = ubi->lookuptbl[pnum]; // return NULL if (e == ubi->move_from) { // NULL == NULL gets true goto retry; // infinite loop !!! $ top PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND 7676 root 20 0 0 0 0 R 100.0 0.0 ubifs_bgt0_0 Fix it by: 1) Letting ubi_wl_put_peb() returns directly if wearl leveling entry has been removed from 'ubi->lookuptbl'. 2) Using 'ubi->wl_lock' protecting wl entry deletion to preventing an use-after-free problem for wl entry in ubi_wl_put_peb(). Fetch a reproducer in [Link].
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Meta Information
Published
2025-10-01
Last Modified
2025-10-02
Generated
2026-05-07
AI Q&A
2025-10-01
EPSS Evaluated
2026-05-05
NVD
CVE-2023-53481
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is an infinite loop in the Linux kernel's UBI (Unsorted Block Images) wear-leveling function ubi_wl_put_peb(). It occurs when the wear-leveling work fails due to a flash fault during reading, causing the function to enter a retry loop indefinitely because a condition comparing NULL pointers always evaluates to true. This leads to 100% CPU usage by the affected process.


How can this vulnerability impact me? :

The vulnerability can cause the affected Linux system to hang or become unresponsive due to a process consuming 100% CPU in an infinite loop. This can degrade system performance, potentially leading to denial of service or disruption of normal operations.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by monitoring for processes stuck in an infinite loop related to the wear-leveling worker in the UBI subsystem. For example, using the command 'top' to check for a process named 'ubifs_bgt0_0' consuming 100% CPU can indicate the issue. Specifically, running 'top' and looking for high CPU usage by 'ubifs_bgt' processes can help detect the problem.


What immediate steps should I take to mitigate this vulnerability?

Immediate mitigation involves applying the fix that prevents the infinite loop by ensuring ubi_wl_put_peb() returns directly if the wear-leveling entry has been removed from 'ubi->lookuptbl', and by using 'ubi->wl_lock' to protect wear-leveling entry deletion to prevent use-after-free issues. Practically, this means updating the Linux kernel to a version that includes this fix.


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