CVE-2023-53501 [Medium] | Information Disclosure in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind When unbinding pasid - a race condition exists vs outstanding page faults. To prevent this, the pasid_state object contains a refcount. * set to 1 on pasid bind * incremented on each ppr notification start * decremented on each ppr notification done * decremented on pasid unbind Since refcount_dec assumes that refcount will never reach 0: the current implementation causes the following to be invoked on pasid unbind: REFCOUNT_WARN("decrement hit 0; leaking memory") Fix this issue by changing refcount_dec to refcount_dec_and_test to explicitly handle refcount=1.

#	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
4.7	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:H/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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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.	1.0	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.7

3.1

MEDIUM

CVSS:3.1/AV:L/AC:H/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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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.

1.0

3.6

[email protected]

OS Trackers for CVE-2023-53501

vendor	priority	summary	link
`debian`	unimportant	CVE-2023-53501 unimportant 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-2023-53501
`redhat`	low	—	https://access.redhat.com/security/cve/CVE-2023-53501
`suse`	medium	CVE-2023-53501 severity moderate: SUSE including 402 source package names (2.1.3-6.80:kernel-default-base-6.4.0-35.1.21.12, 2.1.3-7.57:kernel-default-6.4.0-35.1, …), 821 product×package rows across 172 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (172 product lines)): Fixed 442, Known Affected 231, Known Not Affected 148.	https://www.suse.com/security/cve/CVE-2023-53501/
`ubuntu`	medium	CVE-2023-53501 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 158, not-affected 119, released 119, needs-triage 1.	https://ubuntu.com/security/CVE-2023-53501

Affected software / configurations for CVE-2023-53501

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.15, < 5.15.132	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.53	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.4.16	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.5, < 6.5.3	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2023-53501

URL	Tags
https://git.kernel.org/stable/c/13ed255248dfbbb7f23f9170c7a537fb9ca22c73	Patch
https://git.kernel.org/stable/c/534103bcd52ca9c1fecbc70e717b4a538dc4ded8	Patch
https://git.kernel.org/stable/c/98d86bf32187db27946ca817c2467a5f2f7aa02f	Patch
https://git.kernel.org/stable/c/9ccc51be3126b25cfe9351dbffde946c925cc28a	Patch
https://git.kernel.org/stable/c/a50d60b8f2aff46dd7c7edb4a5835cdc4d432c22	Patch

URL

CVE-2023-53501 | iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind

Exploit prediction scoring system (EPSS) score for CVE-2023-53501

Common vulnerability scoring system (CVSS) metrics for CVE-2023-53501

Weakness enumeration for CVE-2023-53501

OS Trackers for CVE-2023-53501

Affected software / configurations for CVE-2023-53501

References for CVE-2023-53501