{"id":"CVE-2025-21961","state":"PUBLISHED","title":"eth: bnxt: fix truesize for mb-xdp-pass case","description":"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  <IRQ>\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<Node A>\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<Node B>\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.","publishedAt":"2025-04-01T15:46:58.795Z","updatedAt":"2026-10-30T12:21:03.937Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"01492e94a823c50f4ab5084e3ac210ba981133be","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"924ef5959b7cfbee8f923a77b0ad19b5f0a4d526","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"19107e71be330dbccb9f8f9f4cf0a9abeadad802","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"b4679807c6083ade4d47f03f80da891afcb6ef62","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"9f7b2aa5034e24d3c49db73d5f760c0435fe31c2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/bnxt/bnxt.c","drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.20","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.8","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/bnxt/bnxt.c","drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c"]}],"references":["https://git.kernel.org/stable/c/01492e94a823c50f4ab5084e3ac210ba981133be","https://git.kernel.org/stable/c/924ef5959b7cfbee8f923a77b0ad19b5f0a4d526","https://git.kernel.org/stable/c/19107e71be330dbccb9f8f9f4cf0a9abeadad802","https://git.kernel.org/stable/c/b4679807c6083ade4d47f03f80da891afcb6ef62","https://git.kernel.org/stable/c/9f7b2aa5034e24d3c49db73d5f760c0435fe31c2"],"weaknesses":[],"ingestedAt":"2026-10-30T12:38:04.623Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/21xxx/CVE-2025-21961.json","commit":"db8103c5921aac81d5d90efcf3745980dafabf49","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-21961","state":"PUBLISHED","datePublished":"2025-04-01T15:46:58.795Z","dateUpdated":"2026-10-30T12:21:03.937Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-12-29T08:45:45.795Z"},"containers":{"cna":{"title":"eth: bnxt: fix truesize for mb-xdp-pass case","descriptions":[{"lang":"en","value":"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  <IRQ>\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<Node A>\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<Node B>\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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"01492e94a823c50f4ab5084e3ac210ba981133be","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"924ef5959b7cfbee8f923a77b0ad19b5f0a4d526","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"19107e71be330dbccb9f8f9f4cf0a9abeadad802","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"b4679807c6083ade4d47f03f80da891afcb6ef62","versionType":"git"},{"version":"1dc4c557bfedfcdf7fc0c46795857773b7ad66e7","status":"affected","lessThan":"9f7b2aa5034e24d3c49db73d5f760c0435fe31c2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/bnxt/bnxt.c","drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.20","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.8","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/broadcom/bnxt/bnxt.c","drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/01492e94a823c50f4ab5084e3ac210ba981133be"},{"url":"https://git.kernel.org/stable/c/924ef5959b7cfbee8f923a77b0ad19b5f0a4d526"},{"url":"https://git.kernel.org/stable/c/19107e71be330dbccb9f8f9f4cf0a9abeadad802"},{"url":"https://git.kernel.org/stable/c/b4679807c6083ade4d47f03f80da891afcb6ef62"},{"url":"https://git.kernel.org/stable/c/9f7b2aa5034e24d3c49db73d5f760c0435fe31c2"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The bug is triggered entirely by an inbound Ethernet frame processed in the bnxt_en NAPI receive path (bnxt_rx_pkt → 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 — 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 — 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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:21:03.937Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.12.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.13.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.14"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2025-10-01T17:15:46.557576Z","id":"CVE-2025-21961","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"type":"CWE","lang":"en","description":"CWE-noinfo Not enough information"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-10-01T17:15:48.731Z"}}]}}}