CVE-2025-38321 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: smb: Log an error when close_all_cached_dirs fails Under low-memory conditions, close_all_cached_dirs() can't move the dentries to a separate list to dput() them once the locks are dropped. This will result in a "Dentry still in use" error, so add an error message that makes it clear this is what happened: [ 495.281119] CIFS: VFS: \\otters.example.com\share Out of memory while dropping dentries [ 495.281595] ------------[ cut here ]------------ [ 495.281887] BUG: Dentry ffff888115531138{i=78,n=/} still in use (2) [unmount of cifs cifs] [ 495.282391] WARNING: CPU: 1 PID: 2329 at fs/dcache.c:1536 umount_check+0xc8/0xf0 Also, bail out of looping through all tcons as soon as a single allocation fails, since we're already in trouble, and kmalloc() attempts for subseqeuent tcons are likely to fail just like the first one did.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.05%	0.16%	+0.11%
2	2026-05-06	0.02%	0.05%	+0.03%
3	2025-07-10	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.05%

0.16%

+0.11%

2026-05-06

0.02%

0.05%

+0.03%

2025-07-10

—

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-2025-38321

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-38321 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-2025-38321
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-38321
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2025-38321/
`ubuntu`	medium	CVE-2025-38321 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1548 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1142, ignored 168, released 138, needed 77, not-affected 20, needs-triage 2, pending 1.	https://ubuntu.com/security/CVE-2025-38321

Affected software / configurations for CVE-2025-38321

Vendor	Product	Version	Raw CPE
linux	linux_kernel	< 6.6.95	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.35	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.15.4	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.16	cpe:2.3:o:linux:linux_kernel:6.16:rc1::::::
linux	linux_kernel	6.16	cpe:2.3:o:linux:linux_kernel:6.16:rc2::::::

References for CVE-2025-38321

URL	Tags
https://git.kernel.org/stable/c/43f26094d6702e494e800532c3f1606e7a68eb30	Patch
https://git.kernel.org/stable/c/4479db143390bdcadc1561292aab579cdfa9f6c6	Patch
https://git.kernel.org/stable/c/a2182743a8b4969481f64aec4908ff162e8a206c	Patch
https://git.kernel.org/stable/c/b8ced2b9a23a1a2c1e0ed8d0d02512e51bdf38da	Patch

URL

CVE-2025-38321 | smb: Log an error when close_all_cached_dirs fails

Exploit prediction scoring system (EPSS) score for CVE-2025-38321

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38321

Weakness enumeration for CVE-2025-38321

OS Trackers for CVE-2025-38321

Affected software / configurations for CVE-2025-38321

References for CVE-2025-38321