CVE-2025-38442 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: block: reject bs > ps block devices when THP is disabled If THP is disabled and when a block device with logical block size > page size is present, the following null ptr deref panic happens during boot: [ [13.2 mK AOSAN: null-ptr-deref in range [0x0000000000000000-0x0000000000K0 0 0[07] [ 13.017749] RIP: 0010:create_empty_buffers+0x3b/0x380 <snip> [ 13.025448] Call Trace: [ 13.025692] <TASK> [ 13.025895] block_read_full_folio+0x610/0x780 [ 13.026379] ? __pfx_blkdev_get_block+0x10/0x10 [ 13.027008] ? __folio_batch_add_and_move+0x1fa/0x2b0 [ 13.027548] ? __pfx_blkdev_read_folio+0x10/0x10 [ 13.028080] filemap_read_folio+0x9b/0x200 [ 13.028526] ? __pfx_filemap_read_folio+0x10/0x10 [ 13.029030] ? __filemap_get_folio+0x43/0x620 [ 13.029497] do_read_cache_folio+0x155/0x3b0 [ 13.029962] ? __pfx_blkdev_read_folio+0x10/0x10 [ 13.030381] read_part_sector+0xb7/0x2a0 [ 13.030805] read_lba+0x174/0x2c0 <snip> [ 13.045348] nvme_scan_ns+0x684/0x850 [nvme_core] [ 13.045858] ? __pfx_nvme_scan_ns+0x10/0x10 [nvme_core] [ 13.046414] ? _raw_spin_unlock+0x15/0x40 [ 13.046843] ? __switch_to+0x523/0x10a0 [ 13.047253] ? kvm_clock_get_cycles+0x14/0x30 [ 13.047742] ? __pfx_nvme_scan_ns_async+0x10/0x10 [nvme_core] [ 13.048353] async_run_entry_fn+0x96/0x4f0 [ 13.048787] process_one_work+0x667/0x10a0 [ 13.049219] worker_thread+0x63c/0xf60 As large folio support depends on THP, only allow bs > ps block devices if THP is enabled.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-21	0.02%	0.09%	+0.07%
2	2025-07-26	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-21

0.02%

0.09%

+0.07%

2025-07-26

—

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-2025-38442

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-38442 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-2025-38442
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2025-38442
`suse`	medium	CVE-2025-38442 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 281 product×package rows across 55 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (55 product lines)): Known Not Affected 281.	https://www.suse.com/security/cve/CVE-2025-38442/
`ubuntu`	medium	CVE-2025-38442 medium priority: Ubuntu including 144 source packages (linux, linux-allwinner-5.19, …), 1152 status rows across 8 suites (bionic, focal, jammy, noble, plucky, trusty, upstream, xenial): DNE 797, ignored 151, not-affected 127, released 77.	https://ubuntu.com/security/CVE-2025-38442

Affected software / configurations for CVE-2025-38442

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 6.15, < 6.15.7	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::::::
linux	linux_kernel	6.16	cpe:2.3:o:linux:linux_kernel:6.16:rc3::::::
linux	linux_kernel	6.16	cpe:2.3:o:linux:linux_kernel:6.16:rc4::::::
linux	linux_kernel	6.16	cpe:2.3:o:linux:linux_kernel:6.16:rc5::::::

References for CVE-2025-38442

URL	Tags
https://git.kernel.org/stable/c/4cdf1bdd45ac78a088773722f009883af30ad318	Patch
https://git.kernel.org/stable/c/b025d81b96bfe8a62b6e3e6ac776608206ccbf6d	Patch

URL

CVE-2025-38442 | block: reject bs > ps block devices when THP is disabled

Exploit prediction scoring system (EPSS) score for CVE-2025-38442

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38442

Weakness enumeration for CVE-2025-38442

OS Trackers for CVE-2025-38442

Affected software / configurations for CVE-2025-38442

References for CVE-2025-38442