{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50256", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T19:36:19.980Z", "datePublished": "2024-11-09T10:15:09.551Z", "dateUpdated": "2026-08-05T11:42:48.642Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:42:48.642Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()\n\nI got a syzbot report without a repro [1] crashing in nf_send_reset6()\n\nI think the issue is that dev->hard_header_len is zero, and we attempt\nlater to push an Ethernet header.\n\nUse LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.\n\n[1]\n\nskbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun\n kernel BUG at net/core/skbuff.c:206 !\nOops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI\nCPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\n RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]\n RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216\nCode: 0d 8d 48 c7 c6 60 a6 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 ba 30 38 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3\nRSP: 0018:ffffc900045269b0 EFLAGS: 00010282\nRAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800\nRDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000\nRBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc\nR10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140\nR13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c\nFS: 00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \n skb_push+0xe5/0x100 net/core/skbuff.c:2636\n eth_header+0x38/0x1f0 net/ethernet/eth.c:83\n dev_hard_header include/linux/netdevice.h:3208 [inline]\n nf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358\n nft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48\n expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]\n nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288\n nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161\n nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]\n nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626\n nf_hook include/linux/netfilter.h:269 [inline]\n NF_HOOK include/linux/netfilter.h:312 [inline]\n br_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184\n nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]\n nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]\n br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424\n __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562\n __netif_receive_skb_one_core net/core/dev.c:5666 [inline]\n __netif_receive_skb+0x12f/0x650 net/core/dev.c:5781\n netif_receive_skb_internal net/core/dev.c:5867 [inline]\n netif_receive_skb+0x1e8/0x890 net/core/dev.c:5926\n tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550\n tun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007\n tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053\n new_sync_write fs/read_write.c:590 [inline]\n vfs_write+0xa6d/0xc90 fs/read_write.c:683\n ksys_write+0x183/0x2b0 fs/read_write.c:736\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdbeeb7d1ff\nCode: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48\nRSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001\nRAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff\nRDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8\nRBP: 00007fdbeebf12be R08: 0000000\n---truncated---" } ], "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 vulnerable code executes in the netfilter reject path while processing received IPv6 TCP packets (L3/L4 filtering); a remote host's packet routed onto a bridged/filtered segment reaches it, so it is network-triggerable rather than merely adjacent.\nAC:L - Within the assumed vulnerable deployment (bridge netfilter + IPv6 reject-tcp-reset + a RST output device with hard_header_len=0), a single crafted unicast IPv6 TCP packet reliably crashes the kernel; there is no race and no attacker-uncontrollable memory-layout dependency.\nPR:N - A remote unauthenticated attacker only needs to send a matching IPv6 TCP packet that the firewall rejects; no credentials or authentication are required (and the local equivalent is only PR:L via user namespaces).\nUI:N - The crash occurs during automatic packet processing by the firewall; no victim action is needed.\nS:U - The impact is a crash of the same kernel that contains the vulnerable code; no privilege or security boundary is crossed.\nC:N - The BUG() fires at the skb_push guard before any underflow write, and the code path performs no out-of-bounds read; no information is disclosed.\nI:N - The guard aborts execution before any buffer underflow write occurs, so no kernel memory is modified or corrupted.\nA:H - The bug triggers skb_under_panic() → BUG(), an immediate kernel crash/oops (host-wide denial of service), which the guidance classifies as High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/netfilter/nf_reject_ipv6.c" ], "versions": [ { "version": "c8d7b98bec43faaa6583c3135030be5eb4693acb", "lessThan": "4f7b586aae53c2ed820661803da8ce18b1361921", "status": "affected", "versionType": "git" }, { "version": "c8d7b98bec43faaa6583c3135030be5eb4693acb", "lessThan": "fef63832317d9d24e1214cdd8f204d02ebdf8499", "status": "affected", "versionType": "git" }, { "version": "c8d7b98bec43faaa6583c3135030be5eb4693acb", "lessThan": "f85b057e34419e5ec0583a65078a11ccc1d4540a", "status": "affected", "versionType": "git" }, { "version": "c8d7b98bec43faaa6583c3135030be5eb4693acb", "lessThan": "4ed234fe793f27a3b151c43d2106df2ff0d81aac", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/netfilter/nf_reject_ipv6.c" ], "versions": [ { "version": "3.18", "status": "affected" }, { "version": "0", "lessThan": "3.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.116", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.60", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.7", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.1.116" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.6.60" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.11.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4f7b586aae53c2ed820661803da8ce18b1361921" }, { "url": "https://git.kernel.org/stable/c/fef63832317d9d24e1214cdd8f204d02ebdf8499" }, { "url": "https://git.kernel.org/stable/c/f85b057e34419e5ec0583a65078a11ccc1d4540a" }, { "url": "https://git.kernel.org/stable/c/4ed234fe793f27a3b151c43d2106df2ff0d81aac" } ], "title": "netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "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": { "id": "CVE-2024-50256", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2025-10-01T20:15:33.931486Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "description": "CWE-noinfo Not enough information" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-01T20:17:24.429Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:27:36.148Z" } } ] } }