CVE-2025-21960 | eth: bnxt: do not update checksum in bnxt_xdp_build_skb()

In the Linux kernel, the following vulnerability has been resolved: eth: bnxt: do not update checksum in bnxt_xdp_build_skb() The bnxt_rx_pkt() updates ip_summed value at the end if checksum offload is enabled. When the XDP-MB program is attached and it returns XDP_PASS, the bnxt_xdp_build_skb() is called to update skb_shared_info. The main purpose of bnxt_xdp_build_skb() is to update skb_shared_info, but it updates ip_summed value too if checksum offload is enabled. This is actually duplicate work. When the bnxt_rx_pkt() updates ip_summed value, it checks if ip_summed is CHECKSUM_NONE or not. It means that ip_summed should be CHECKSUM_NONE at this moment. But ip_summed may already be updated to CHECKSUM_UNNECESSARY in the XDP-MB-PASS path. So the by skb_checksum_none_assert() WARNS about it. This is duplicate work and updating ip_summed in the bnxt_xdp_build_skb() is not needed. Splat looks like: WARNING: CPU: 3 PID: 5782 at ./include/linux/skbuff.h:5155 bnxt_rx_pkt+0x479b/0x7610 [bnxt_en] Modules linked in: bnxt_re bnxt_en rdma_ucm rdma_cm iw_cm ib_cm ib_uverbs veth xt_nat xt_tcpudp xt_conntrack nft_chain_nat xt_MASQUERADE nf_] CPU: 3 UID: 0 PID: 5782 Comm: socat Tainted: G W 6.14.0-rc4+ #27 Tainted: [W]=WARN Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:bnxt_rx_pkt+0x479b/0x7610 [bnxt_en] Code: 54 24 0c 4c 89 f1 4c 89 ff c1 ea 1f ff d3 0f 1f 00 49 89 c6 48 85 c0 0f 84 4c e5 ff ff 48 89 c7 e8 ca 3d a0 c8 e9 8f f4 ff ff <0f> 0b f RSP: 0018:ffff88881ba09928 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 00000000c7590303 RCX: 0000000000000000 RDX: 1ffff1104e7d1610 RSI: 0000000000000001 RDI: ffff8881c91300b8 RBP: ffff88881ba09b28 R08: ffff888273e8b0d0 R09: ffff888273e8b070 R10: ffff888273e8b010 R11: ffff888278b0f000 R12: ffff888273e8b080 R13: ffff8881c9130e00 R14: ffff8881505d3800 R15: ffff888273e8b000 FS: 00007f5a2e7be080(0000) GS:ffff88881ba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff2e708ff8 CR3: 000000013e3b0000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <IRQ> ? __warn+0xcd/0x2f0 ? bnxt_rx_pkt+0x479b/0x7610 ? report_bug+0x326/0x3c0 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x14/0x50 ? asm_exc_invalid_op+0x16/0x20 ? bnxt_rx_pkt+0x479b/0x7610 ? bnxt_rx_pkt+0x3e41/0x7610 ? __pfx_bnxt_rx_pkt+0x10/0x10 ? napi_complete_done+0x2cf/0x7d0 __bnxt_poll_work+0x4e8/0x1220 ? __pfx___bnxt_poll_work+0x10/0x10 ? __pfx_mark_lock.part.0+0x10/0x10 bnxt_poll_p5+0x36a/0xfa0 ? __pfx_bnxt_poll_p5+0x10/0x10 __napi_poll.constprop.0+0xa0/0x440 net_rx_action+0x899/0xd00 ... Following ping.py patch adds xdp-mb-pass case. so ping.py is going to be able to reproduce this issue.

Published: 2025-04-01 Last update: 2025-11-03 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-21960 is rated Low Risk (23.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-21960

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-10 0.09% 0.02% -0.07%
2 2026-01-26 0.03% 0.09% +0.06%
3 2025-08-28 0.03%

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21960

CVSS metrics for this CVE.

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]

Weakness enumeration for CVE-2025-21960

OS Trackers for CVE-2025-21960

vendor priority summary link
debian unimportant CVE-2025-21960 unimportant 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-2025-21960
redhat medium https://access.redhat.com/security/cve/CVE-2025-21960
suse medium https://www.suse.com/security/cve/CVE-2025-21960/
ubuntu medium CVE-2025-21960 medium priority: Ubuntu including 150 source packages (linux, linux-allwinner-5.19, …), 1487 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1097, ignored 150, released 130, not-affected 110. https://ubuntu.com/security/CVE-2025-21960

Affected software / configurations for CVE-2025-21960

Vendor Product Version Raw CPE
linux linux_kernel >= 5.19, < 6.1.132 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.84 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.20 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.13.8 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
linux linux_kernel 6.14 cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*

References for CVE-2025-21960

cvelogic Threat Intelligence