CVE-2024-56648 net: hsr: avoid potential out-of-bound access in fill_frame_info()

What is CVE-2024-56648?

CVE-2024-56648 is a medium-severity memory corruption vulnerability in Linux kernel, published on 27 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

net: hsr: avoid potential out-of-bound access in fill_frame_info()

syzbot is able to feed a packet with 14 bytes, pretending it is a vlan one.

Since fill_frame_info() is relying on skb->mac_len already, extend the check to cover this case.

BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:709 [inline] BUG: KMSAN: uninit-value in hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724 fill_frame_info net/hsr/hsr_forward.c:709 [inline] hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724 hsr_dev_xmit+0x2f0/0x350 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5002 [inline] netdev_start_xmit include/linux/netdevice.h:5011 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3606 __dev_queue_xmit+0x366a/0x57d0 net/core/dev.c:4434 dev_queue_xmit include/linux/netdevice.h:3168 [inline] packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3146 [inline] packet_sendmsg+0x91ae/0xa6f0 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:726 __sys_sendto+0x594/0x750 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2200 x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at: slab_post_alloc_hook mm/slub.c:4091 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2881 packet_alloc_skb net/packet/af_packet.c:2995 [inline] packet_snd net/packet/af_packet.c:3089 [inline] packet_sendmsg+0x74c6/0xa6f0 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:726 __sys_sendto+0x594/0x750 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2200 x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Weakness: CWE-908

Which versions are affected by CVE-2024-56648?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-56648?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2024-56648 being exploited?

There is no known exploitation of CVE-2024-56648 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-54785, AZL-54818, BELL-CVE-2024-56648, DEBIAN-CVE-2024-56648, GHSA-x8gq-4mj9-v7xj, SUSE-SU-2025:0889-1 and 4 more.