CVE-2023-53481 [Medium] | Use-After-Free in Linux Kernel

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].

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-10-01	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-10-01

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

OS Trackers for CVE-2023-53481

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2023-53481 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2023-53481
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2023-53481
`suse`	medium	CVE-2023-53481 severity moderate: SUSE including 25 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 268 product×package rows across 54 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (54 product lines)): Known Not Affected 268.	https://www.suse.com/security/cve/CVE-2023-53481/
`ubuntu`	medium	CVE-2023-53481 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 162, released 138, not-affected 77, needed 19, needs-triage 1.	https://ubuntu.com/security/CVE-2023-53481

Affected software / configurations for CVE-2023-53481

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 2.6.25, < 4.14.308	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.15, < 4.19.276	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.20, < 5.4.235	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.173	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.100	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.18	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.2.5	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2023-53481

URL	Tags
https://git.kernel.org/stable/c/3afaaf6f5867dc4ad383808d4053f428ec7b867d	Patch
https://git.kernel.org/stable/c/4d57a7333e26040f2b583983e1970d9d460e56b0	Patch
https://git.kernel.org/stable/c/5af1c643184a5d09ff5b3f334077a4d0a163c677	Patch
https://git.kernel.org/stable/c/8a18856e074479bd050b01e688c58defadce7ab0	Patch
https://git.kernel.org/stable/c/b40d2fbf47af58377e898b5062077a47bb28a132	Patch
https://git.kernel.org/stable/c/b5be23f6ae610bdb262160a1f294afee6d0e6a69	Patch
https://git.kernel.org/stable/c/cc4bc532acda66189bddc03b3fe1ad689d9a48a2	Patch
https://git.kernel.org/stable/c/f006f596fe851c3b6aae60b79f89f89f0e515d2f	Patch

URL

CVE-2023-53481 | ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed

Exploit prediction scoring system (EPSS) score for CVE-2023-53481

Common vulnerability scoring system (CVSS) metrics for CVE-2023-53481

Weakness enumeration for CVE-2023-53481

OS Trackers for CVE-2023-53481

Affected software / configurations for CVE-2023-53481

References for CVE-2023-53481