CVE-2024-33621ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound

In the Linux kernel, the following vulnerability has been resolved: ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound Raw packet from PF_PACKET socket ontop of an IPv6-backed ipvlan device will hit WARN_ON_ONCE() in sk_mc_loop() through sch_direct_xmit() path. WARNING: CPU: 2 PID: 0 at net/core/sock.c:775 sk_mc_loop+0x2d/0x70 Modules linked in: sch_netem ipvlan rfkill cirrus drm_shmem_helper sg drm_kms_helper CPU: 2 PID: 0 Comm: swapper/2 Kdump: loaded Not tainted 6.9.0+ #279 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:sk_mc_loop+0x2d/0x70 Code: 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 RSP: 0018:ffffa9584015cd78 EFLAGS: 00010212 RAX: 0000000000000011 RBX: ffff91e585793e00 RCX: 0000000002c6a001 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff91e589c0f000 RBP: ffff91e5855bd100 R08: 0000000000000000 R09: 3d00545216f43d00 R10: ffff91e584fdcc50 R11: 00000060dd8616f4 R12: ffff91e58132d000 R13: ffff91e584fdcc68 R14: ffff91e5869ce800 R15: ffff91e589c0f000 FS: 0000000000000000(0000) GS:ffff91e898100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f788f7c44c0 CR3: 0000000008e1a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> ? __warn (kernel/panic.c:693) ? sk_mc_loop (net/core/sock.c:760) ? report_bug (lib/bug.c:201 lib/bug.c:219) ? handle_bug (arch/x86/kernel/traps.c:239) ? exc_invalid_op (arch/x86/kernel/traps.c:260 (discriminator 1)) ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) ? sk_mc_loop (net/core/sock.c:760) ip6_finish_output2 (net/ipv6/ip6_output.c:83 (discriminator 1)) ? nf_hook_slow (net/netfilter/core.c:626) ip6_finish_output (net/ipv6/ip6_output.c:222) ? __pfx_ip6_finish_output (net/ipv6/ip6_output.c:215) ipvlan_xmit_mode_l3 (drivers/net/ipvlan/ipvlan_core.c:602) ipvlan ipvlan_start_xmit (drivers/net/ipvlan/ipvlan_main.c:226) ipvlan dev_hard_start_xmit (net/core/dev.c:3594) sch_direct_xmit (net/sched/sch_generic.c:343) __qdisc_run (net/sched/sch_generic.c:416) net_tx_action (net/core/dev.c:5286) handle_softirqs (kernel/softirq.c:555) __irq_exit_rcu (kernel/softirq.c:589) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043) The warning triggers as this: packet_sendmsg packet_snd //skb->sk is packet sk __dev_queue_xmit __dev_xmit_skb //q->enqueue is not NULL __qdisc_run sch_direct_xmit dev_hard_start_xmit ipvlan_start_xmit ipvlan_xmit_mode_l3 //l3 mode ipvlan_process_outbound //vepa flag ipvlan_process_v6_outbound ip6_local_out __ip6_finish_output ip6_finish_output2 //multicast packet sk_mc_loop //sk->sk_family is AF_PACKET Call ip{6}_local_out() with NULL sk in ipvlan as other tunnels to fix this.

CVSS

5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Modified

Record last updated

Oct 15, 2026

First seen by InfoSec Signals

Oct 15, 2026

The CVE record on cve.org · NVD's entry

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