CVE-2025-38439 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT When transmitting an XDP_REDIRECT packet, call dma_unmap_len_set() with the proper length instead of 0. This bug triggers this warning on a system with IOMMU enabled: WARNING: CPU: 36 PID: 0 at drivers/iommu/dma-iommu.c:842 __iommu_dma_unmap+0x159/0x170 RIP: 0010:__iommu_dma_unmap+0x159/0x170 Code: a8 00 00 00 00 48 c7 45 b0 00 00 00 00 48 c7 45 c8 00 00 00 00 48 c7 45 a0 ff ff ff ff 4c 89 45 b8 4c 89 45 c0 e9 77 ff ff ff <0f> 0b e9 60 ff ff ff e8 8b bf 6a 00 66 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ff22d31181150c88 EFLAGS: 00010206 RAX: 0000000000002000 RBX: 00000000e13a0000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ff22d31181150cf0 R08: ff22d31181150ca8 R09: 0000000000000000 R10: 0000000000000000 R11: ff22d311d36c9d80 R12: 0000000000001000 R13: ff13544d10645010 R14: ff22d31181150c90 R15: ff13544d0b2bac00 FS: 0000000000000000(0000) GS:ff13550908a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005be909dacff8 CR3: 0008000173408003 CR4: 0000000000f71ef0 PKRU: 55555554 Call Trace: <IRQ> ? show_regs+0x6d/0x80 ? __warn+0x89/0x160 ? __iommu_dma_unmap+0x159/0x170 ? report_bug+0x17e/0x1b0 ? handle_bug+0x46/0x90 ? exc_invalid_op+0x18/0x80 ? asm_exc_invalid_op+0x1b/0x20 ? __iommu_dma_unmap+0x159/0x170 ? __iommu_dma_unmap+0xb3/0x170 iommu_dma_unmap_page+0x4f/0x100 dma_unmap_page_attrs+0x52/0x220 ? srso_alias_return_thunk+0x5/0xfbef5 ? xdp_return_frame+0x2e/0xd0 bnxt_tx_int_xdp+0xdf/0x440 [bnxt_en] __bnxt_poll_work_done+0x81/0x1e0 [bnxt_en] bnxt_poll+0xd3/0x1e0 [bnxt_en]

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.07%	0.16%	+0.09%
2	2026-05-21	0.04%	0.07%	+0.03%
3	2025-12-21	—	0.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.07%

0.16%

+0.09%

2026-05-21

0.04%

0.07%

+0.03%

2025-12-21

—

0.04%

—

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-2025-38439

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2025-38439 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6.	https://security-tracker.debian.org/tracker/CVE-2025-38439
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-38439
`suse`	low	CVE-2025-38439 severity low: SUSE including 470 source package names (2.1.3-6.73:kernel-default-base-6.4.0-34.1.21.11, 2.1.3-7.50:kernel-default-6.4.0-34.1, …), 935 product×package rows across 189 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (189 product lines)): Fixed 627, Known Affected 231, Known Not Affected 56, First Fixed 21.	https://www.suse.com/security/cve/CVE-2025-38439/
`ubuntu`	medium	CVE-2025-38439 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, released 169, ignored 157, not-affected 41, needed 26, needs-triage 2, pending 2.	https://ubuntu.com/security/CVE-2025-38439

Affected software / configurations for CVE-2025-38439

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.3, < 5.4.296	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.240	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.189	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.146	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.6.99	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.39	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 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::::::
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2025-38439

URL	Tags
https://git.kernel.org/stable/c/16ae306602163fcb7ae83f2701b542e43c100cee	Patch
https://git.kernel.org/stable/c/3cdf199d4755d477972ee87110b2aebc88b3cfad	Patch
https://git.kernel.org/stable/c/50dad9909715094e7d9ca25e9e0412b875987519	Patch
https://git.kernel.org/stable/c/5909679a82cd74cf0343d9e3ddf4b6931aa7e613	Patch
https://git.kernel.org/stable/c/8d672a1a6bfc81fef9151925c9c0481f4acf4bec	Patch
https://git.kernel.org/stable/c/e260f4d49370c85a4701d43c6d16b8c39f8b605f	Patch
https://git.kernel.org/stable/c/f154e41e1d9d15ab21300ba7bbf0ebb5cb3b9c2a	Patch
https://git.kernel.org/stable/c/f9eaf6d036075dc820520e1194692c0619b7297b	Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html	Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html	Third Party Advisory

URL

CVE-2025-38439 | bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT

Exploit prediction scoring system (EPSS) score for CVE-2025-38439

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38439

Weakness enumeration for CVE-2025-38439

OS Trackers for CVE-2025-38439

Affected software / configurations for CVE-2025-38439

References for CVE-2025-38439