{ "schema_version": "1.6.1", "id": "RPI-CVE-2025-21961", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2025-21961" ], "published": "2025-04-01T15:46:27Z", "summary": "eth: bnxt: fix truesize for mb-xdp-pass case", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\neth: bnxt: fix truesize for mb-xdp-pass case\n\nWhen mb-xdp is set and return is XDP_PASS, packet is converted from\nxdp_buff to sk_buff with xdp_update_skb_shared_info() in\nbnxt_xdp_build_skb().\nbnxt_xdp_build_skb() passes incorrect truesize argument to\nxdp_update_skb_shared_info().\nThe truesize is calculated as BNXT_RX_PAGE_SIZE * sinfo->nr_frags but\nthe skb_shared_info was wiped by napi_build_skb() before.\nSo it stores sinfo->nr_frags before bnxt_xdp_build_skb() and use it\ninstead of getting skb_shared_info from xdp_get_shared_info_from_buff().\n\nSplat looks like:\n ------------[ cut here ]------------\n WARNING: CPU: 2 PID: 0 at net/core/skbuff.c:6072 skb_try_coalesce+0x504/0x590\n Modules linked in: xt_nat xt_tcpudp veth af_packet xt_conntrack nft_chain_nat xt_MASQUERADE nf_conntrack_netlink xfrm_user xt_addrtype nft_coms\n CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.14.0-rc2+ #3\n RIP: 0010:skb_try_coalesce+0x504/0x590\n Code: 4b fd ff ff 49 8b 34 24 40 80 e6 40 0f 84 3d fd ff ff 49 8b 74 24 48 40 f6 c6 01 0f 84 2e fd ff ff 48 8d 4e ff e9 25 fd ff ff <0f> 0b e99\n RSP: 0018:ffffb62c4120caa8 EFLAGS: 00010287\n RAX: 0000000000000003 RBX: ffffb62c4120cb14 RCX: 0000000000000ec0\n RDX: 0000000000001000 RSI: ffffa06e5d7dc000 RDI: 0000000000000003\n RBP: ffffa06e5d7ddec0 R08: ffffa06e6120a800 R09: ffffa06e7a119900\n R10: 0000000000002310 R11: ffffa06e5d7dcec0 R12: ffffe4360575f740\n R13: ffffe43600000000 R14: 0000000000000002 R15: 0000000000000002\n FS: 0000000000000000(0000) GS:ffffa0755f700000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f147b76b0f8 CR3: 00000001615d4000 CR4: 00000000007506f0\n PKRU: 55555554\n Call Trace:\n \n ? __warn+0x84/0x130\n ? skb_try_coalesce+0x504/0x590\n ? report_bug+0x18a/0x1a0\n ? handle_bug+0x53/0x90\n ? exc_invalid_op+0x14/0x70\n ? asm_exc_invalid_op+0x16/0x20\n ? skb_try_coalesce+0x504/0x590\n inet_frag_reasm_finish+0x11f/0x2e0\n ip_defrag+0x37a/0x900\n ip_local_deliver+0x51/0x120\n ip_sublist_rcv_finish+0x64/0x70\n ip_sublist_rcv+0x179/0x210\n ip_list_rcv+0xf9/0x130\n\nHow to reproduce:\n\nip link set $interface1 xdp obj xdp_pass.o\nip link set $interface1 mtu 9000 up\nip a a 10.0.0.1/24 dev $interface1\n\nip link set $interfac2 mtu 9000 up\nip a a 10.0.0.2/24 dev $interface2\nping 10.0.0.1 -s 65000\n\nFollowing ping.py patch adds xdp-mb-pass case. so ping.py is going to be\nable to reproduce this issue.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null, "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2025-21961" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/19107e71be330dbccb9f8f9f4cf0a9abeadad802" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/b4679807c6083ade4d47f03f80da891afcb6ef62" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9f7b2aa5034e24d3c49db73d5f760c0435fe31c2" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T12:19:11Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.5, "cvss_v3_severity": "High", "scenario": "AV:N - The bug is triggered entirely by an inbound Ethernet frame processed in the bnxt_en NAPI receive path (bnxt_rx_pkt \u2192 bnxt_xdp_build_skb), with the splat landing in ip_defrag()/skb_try_coalesce(); no local access to the target is required. Jumbo/multi-buffer frames are routable end-to-end inside jumbo-enabled datacenter and cloud VPC fabrics, so the sender need not share the victim's L2 segment.\nAC:L - On an affected host (Broadcom NetXtreme NIC, jumbo MTU, multi-buffer XDP program returning XDP_PASS) every oversized packet deterministically produces the wrong truesize \u2014 the upstream reproducer is a single `ping -s 65000`. There is no race to win and no memory-layout condition outside the attacker's control.\nPR:N - The vulnerable code executes in softirq/NAPI context on raw received frames, long before any socket lookup, authentication, or capability check. An unauthenticated attacker with no account on the target simply emits packets.\nUI:N - No victim action is needed at attack time; the XDP program and jumbo MTU are pre-existing deployment configuration, not interaction solicited from a user. Packet arrival alone drives the entire path.\nS:U - The miscounted truesize corrupts skb and socket memory accounting within the same kernel security authority that owns the RX path. No VM, container, or IOMMU boundary is crossed.\nC:N - Only the truesize accounting field is wrong; skb->frags[] and xdp_frags_size retain their correct values, so no out-of-bounds or uninitialized memory is read or exposed to userspace. Nothing is disclosed to the attacker.\nI:N - There is no out-of-bounds write, type confusion, or control-flow corruption \u2014 the erroneous value only skews internal memory-accounting counters, whose consequence is availability rather than data modification.\nA:H - The under-counted truesize trips WARN_ON_ONCE(delta < len) in skb_try_coalesce() during IP reassembly, which is an immediate kernel panic on the panic_on_warn configurations common in cloud and hardened fleets. Even without panic_on_warn, sk_rmem_alloc/sk_forward_alloc and the IP-defrag memory limit are under-charged by roughly the frag count, letting a remote flood pin several times the configured buffer memory and drive the system to OOM." } } }