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

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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.

The Linux kernel CVE team has assigned CVE-2024-33621 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 4.19.316 with commit 0049a623dfbb
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 5.4.278 with commit 54768bacfde6
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 5.10.219 with commit 1abbf079da59
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 5.15.161 with commit 183c4b416454
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 6.1.93 with commit cb53706a3403
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 6.6.33 with commit 54213c09801e
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 6.9.4 with commit 13c4543db34e
	Issue introduced in 3.19 with commit 2ad7bf363841 and fixed in 6.10 with commit b3dc6e8003b5

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-33621
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ipvlan/ipvlan_core.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/0049a623dfbbb49888de7f0c2f33a582b5ead989
	https://git.kernel.org/stable/c/54768bacfde60e8e4757968d79f8726711dd2cf5
	https://git.kernel.org/stable/c/1abbf079da59ef559d0ab4219d2a0302f7970761
	https://git.kernel.org/stable/c/183c4b416454b9983dc1b8aa0022b748911adc48
	https://git.kernel.org/stable/c/cb53706a3403ba67f4040b2a82d9cf79e11b1a48
	https://git.kernel.org/stable/c/54213c09801e0bd2549ac42961093be36f65a7d0
	https://git.kernel.org/stable/c/13c4543db34e0da5a7d2f550b6262d860f248381
	https://git.kernel.org/stable/c/b3dc6e8003b500861fa307e9a3400c52e78e4d3a