CVE-2025-21890

In the Linux kernel, the following vulnerability has been resolved:

idpf: fix checksums set in idpf_rx_rsc()

idpf_rx_rsc() uses skb_transport_offset(skb) while the transport header is not set yet.

This triggers the following warning for CONFIG_DEBUG_NET=y builds.

DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb))

[ 69.261620] WARNING: CPU: 7 PID: 0 at ./include/linux/skbuff.h:3020 idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf [ 69.261629] Modules linked in: vfat fat dummy bridge intel_uncore_frequency_tpmi intel_uncore_frequency_common intel_vsec_tpmi idpf intel_vsec cdc_ncm cdc_eem cdc_ether usbnet mii xhci_pci xhci_hcd ehci_pci ehci_hcd libeth [ 69.261644] CPU: 7 UID: 0 PID: 0 Comm: swapper/7 Tainted: G S W 6.14.0-smp-DEV #1697 [ 69.261648] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN [ 69.261650] RIP: 0010:idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf [ 69.261677] ? __warn (kernel/panic.c:242 kernel/panic.c:748) [ 69.261682] ? idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf [ 69.261687] ? report_bug (lib/bug.c:?) [ 69.261690] ? handle_bug (arch/x86/kernel/traps.c:285) [ 69.261694] ? exc_invalid_op (arch/x86/kernel/traps.c:309) [ 69.261697] ? asm_exc_invalid_op (arch/x86/include/asm/idtentry.h:621) [ 69.261700] ? __pfx_idpf_vport_splitq_napi_poll (drivers/net/ethernet/intel/idpf/idpf_txrx.c:4011) idpf [ 69.261704] ? idpf_vport_splitq_napi_poll (include/linux/skbuff.h:3020) idpf [ 69.261708] ? idpf_vport_splitq_napi_poll (drivers/net/ethernet/intel/idpf/idpf_txrx.c:3072) idpf [ 69.261712] __napi_poll (net/core/dev.c:7194) [ 69.261716] net_rx_action (net/core/dev.c:7265) [ 69.261718] ? __qdisc_run (net/sched/sch_generic.c:293) [ 69.261721] ? sched_clock (arch/x86/include/asm/preempt.h:84 arch/x86/kernel/tsc.c:288) [ 69.261726] handle_softirqs (kernel/softirq.c:561)

A low impact flaw was found in the Linux kernel Intel IDPF Ethernet driver. When processing receive-segment-coalesced (RSC) packets, idpf_rx_rsc() in drivers/net/ethernet/intel/idpf uses skb_transport_offset() before the transport header has been set on the socket buffer, which triggers a DEBUG_NET_WARN_ON_ONCE kernel warning on kernels built with CONFIG_DEBUG_NET=y. Red Hat Product Security rated this flaw Low impact: it is a debug assertion failure rather than memory corruption, with no confidentiality or integrity impact and only limited availability impact. Red Hat Enterprise Linux 9 (kernel and kernel-rt), Red Hat Enterprise Linux 10 (kernel), and Red Hat In-Vehicle OS 1 (kernel) contain the affected code and are marked affected; the fix is currently deferred because the issue only manifests as a warning in debug-enabled builds and poses no practical risk to production kernels, so the residual risk is limited to spurious kernel warnings and log noise on CONFIG_DEBUG_DEBUG_NET configurations. Red Hat Enterprise Linux 6 and 7 are not affected because the vulnerable code is not present. The upstream CVEORG severity of 8.2 (Important) is not supported by the evidence, which shows a local, debug-build-only warning; the Red Hat (2.3, Low) and NIST (5.5, Moderate) scores better reflect the actual impact.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.