{"cve":"CVE-2024-33621","nvd":{"published":"2024-06-21T11:15:09.860","modified":"2026-10-15T01:17:44.917","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound\n\nRaw packet from PF_PACKET socket ontop of an IPv6-backed ipvlan device will\nhit WARN_ON_ONCE() in sk_mc_loop() through sch_direct_xmit() path.\n\nWARNING: CPU: 2 PID: 0 at net/core/sock.c:775 sk_mc_loop+0x2d/0x70\nModules linked in: sch_netem ipvlan rfkill cirrus drm_shmem_helper sg drm_kms_helper\nCPU: 2 PID: 0 Comm: swapper/2 Kdump: loaded Not tainted 6.9.0+ #279\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nRIP: 0010:sk_mc_loop+0x2d/0x70\nCode: fa 0f 1f 44 00 00 65 0f b7 15 f7 96 a3 4f 31 c0 66 85 d2 75 26 48 85 ff 74 1c\nRSP: 0018:ffffa9584015cd78 EFLAGS: 00010212\nRAX: 0000000000000011 RBX: ffff91e585793e00 RCX: 0000000002c6a001\nRDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff91e589c0f000\nRBP: ffff91e5855bd100 R08: 0000000000000000 R09: 3d00545216f43d00\nR10: ffff91e584fdcc50 R11: 00000060dd8616f4 R12: ffff91e58132d000\nR13: ffff91e584fdcc68 R14: ffff91e5869ce800 R15: ffff91e589c0f000\nFS:  0000000000000000(0000) GS:ffff91e898100000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f788f7c44c0 CR3: 0000000008e1a000 CR4: 00000000000006f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n<IRQ>\n ? __warn (kernel/panic.c:693)\n ? sk_mc_loop (net/core/sock.c:760)\n ? report_bug (lib/bug.c:201 lib/bug.c:219)\n ? handle_bug (arch/x86/kernel/traps.c:239)\n ? exc_invalid_op (arch/x86/kernel/traps.c:260 (discriminator 1))\n ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)\n ? sk_mc_loop (net/core/sock.c:760)\n ip6_finish_output2 (net/ipv6/ip6_output.c:83 (discriminator 1))\n ? nf_hook_slow (net/netfilter/core.c:626)\n ip6_finish_output (net/ipv6/ip6_output.c:222)\n ? __pfx_ip6_finish_output (net/ipv6/ip6_output.c:215)\n ipvlan_xmit_mode_l3 (drivers/net/ipvlan/ipvlan_core.c:602) ipvlan\n ipvlan_start_xmit (drivers/net/ipvlan/ipvlan_main.c:226) ipvlan\n dev_hard_start_xmit (net/core/dev.c:3594)\n sch_direct_xmit (net/sched/sch_generic.c:343)\n __qdisc_run (net/sched/sch_generic.c:416)\n net_tx_action (net/core/dev.c:5286)\n handle_softirqs (kernel/softirq.c:555)\n __irq_exit_rcu (kernel/softirq.c:589)\n sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043)\n\nThe warning triggers as this:\npacket_sendmsg\n   packet_snd //skb->sk is packet sk\n      __dev_queue_xmit\n         __dev_xmit_skb //q->enqueue is not NULL\n             __qdisc_run\n               sch_direct_xmit\n                 dev_hard_start_xmit\n                   ipvlan_start_xmit\n                      ipvlan_xmit_mode_l3 //l3 mode\n                        ipvlan_process_outbound //vepa flag\n                          ipvlan_process_v6_outbound\n                            ip6_local_out\n                                __ip6_finish_output\n                                  ip6_finish_output2 //multicast packet\n                                    sk_mc_loop //sk->sk_family is AF_PACKET\n\nCall ip{6}_local_out() with NULL sk in ipvlan as other tunnels to fix this.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0049a623dfbbb49888de7f0c2f33a582b5ead989","https://git.kernel.org/stable/c/13c4543db34e0da5a7d2f550b6262d860f248381","https://git.kernel.org/stable/c/183c4b416454b9983dc1b8aa0022b748911adc48","https://git.kernel.org/stable/c/1abbf079da59ef559d0ab4219d2a0302f7970761","https://git.kernel.org/stable/c/54213c09801e0bd2549ac42961093be36f65a7d0"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:00.836172422+00:00"},"epss":{"cve":"CVE-2024-33621","score":0.00268,"percentile":0.18724,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}