Linux Kernel up to 6.1.115/6.6.59/6.11.6 macsec metadata_dst_free SCI use after free

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.115/6.6.59/6.11.6. Affected by this issue is the function metadata_dst_free of the component macsec. This manipulation of the argument SCI causes use after free. The identification of this vulnerability is CVE-2024-50261. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.115/6.6.59/6.11.6. It has been declared as critical. Affected by this vulnerability is the function metadata_dst_free of the component macsec. The manipulation of the argument SCI with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: macsec: Fix use-after-free while sending the offloading packet KASAN reports the following UAF. The metadata_dst, which is used to store the SCI value for macsec offload, is already freed by metadata_dst_free() in macsec_free_netdev(), while driver still use it for sending the packet. To fix this issue, dst_release() is used instead to release metadata_dst. So it is not freed instantly in macsec_free_netdev() if still referenced by skb. BUG: KASAN: slab-use-after-free in mlx5e_xmit+0x1e8f/0x4190 [mlx5_core] Read of size 2 at addr ffff88813e42e038 by task kworker/7:2/714 [...] Workqueue: mld mld_ifc_work Call Trace: dump_stack_lvl+0x51/0x60 print_report+0xc1/0x600 kasan_report+0xab/0xe0 mlx5e_xmit+0x1e8f/0x4190 [mlx5_core] dev_hard_start_xmit+0x120/0x530 sch_direct_xmit+0x149/0x11e0 __qdisc_run+0x3ad/0x1730 __dev_queue_xmit+0x1196/0x2ed0 vlan_dev_hard_start_xmit+0x32e/0x510 [8021q] dev_hard_start_xmit+0x120/0x530 __dev_queue_xmit+0x14a7/0x2ed0 macsec_start_xmit+0x13e9/0x2340 dev_hard_start_xmit+0x120/0x530 __dev_queue_xmit+0x14a7/0x2ed0 ip6_finish_output2+0x923/0x1a70 ip6_finish_output+0x2d7/0x970 ip6_output+0x1ce/0x3a0 NF_HOOK.constprop.0+0x15f/0x190 mld_sendpack+0x59a/0xbd0 mld_ifc_work+0x48a/0xa80 process_one_work+0x5aa/0xe50 worker_thread+0x79c/0x1290 kthread+0x28f/0x350 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x11/0x20 Allocated by task 3922: kasan_save_stack+0x20/0x40 kasan_save_track+0x10/0x30 __kasan_kmalloc+0x77/0x90 __kmalloc_noprof+0x188/0x400 metadata_dst_alloc+0x1f/0x4e0 macsec_newlink+0x914/0x1410 __rtnl_newlink+0xe08/0x15b0 rtnl_newlink+0x5f/0x90 rtnetlink_rcv_msg+0x667/0xa80 netlink_rcv_skb+0x12c/0x360 netlink_unicast+0x551/0x770 netlink_sendmsg+0x72d/0xbd0 __sock_sendmsg+0xc5/0x190 ____sys_sendmsg+0x52e/0x6a0 ___sys_sendmsg+0xeb/0x170 __sys_sendmsg+0xb5/0x140 do_syscall_64+0x4c/0x100 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 4011: kasan_save_stack+0x20/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x50 poison_slab_object+0x10c/0x190 __kasan_slab_free+0x11/0x30 kfree+0xe0/0x290 macsec_free_netdev+0x3f/0x140 netdev_run_todo+0x450/0xc70 rtnetlink_rcv_msg+0x66f/0xa80 netlink_rcv_skb+0x12c/0x360 netlink_unicast+0x551/0x770 netlink_sendmsg+0x72d/0xbd0 __sock_sendmsg+0xc5/0x190 ____sys_sendmsg+0x52e/0x6a0 ___sys_sendmsg+0xeb/0x170 __sys_sendmsg+0xb5/0x140 do_syscall_64+0x4c/0x100 entry_SYSCALL_64_after_hwframe+0x4b/0x53

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2024-50261 since 10/21/2024. The exploitation appears to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/17/2025).

The vulnerability scanner Nessus provides a plugin with the ID 211777 (Debian dsa-5818 : affs-modules-6.1.0-21-4kc-malta-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.116, 6.6.60 or 6.11.7 eliminates this vulnerability. Applying the patch 872932cf75cf/9f5ae743dbe9/4614640f1d5c/f1e54d11b210 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (211777) and CERT Bund (WID-SEC-2024-3397). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Open Source eCryptfs
• Siemens SIMATIC S7
• SUSE openSUSE
• RESF Rocky Linux
• Dell NetWorker
• Dell Avamar
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.115
• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.6.54
• 6.6.55
• 6.6.56
• 6.6.57
• 6.6.58
• 6.6.59
• 6.11.0
• 6.11.1
• 6.11.2
• 6.11.3
• 6.11.4
• 6.11.5
• 6.11.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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