{"id":"CVE-2024-50261","state":"PUBLISHED","title":"macsec: Fix use-after-free while sending the offloading packet","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: Fix use-after-free while sending the offloading packet\n\nKASAN reports the following UAF. The metadata_dst, which is used to\nstore the SCI value for macsec offload, is already freed by\nmetadata_dst_free() in macsec_free_netdev(), while driver still use it\nfor sending the packet.\n\nTo fix this issue, dst_release() is used instead to release\nmetadata_dst. So it is not freed instantly in macsec_free_netdev() if\nstill referenced by skb.\n\n BUG: KASAN: slab-use-after-free in mlx5e_xmit+0x1e8f/0x4190 [mlx5_core]\n Read of size 2 at addr ffff88813e42e038 by task kworker/7:2/714\n [...]\n Workqueue: mld mld_ifc_work\n Call Trace:\n  <TASK>\n  dump_stack_lvl+0x51/0x60\n  print_report+0xc1/0x600\n  kasan_report+0xab/0xe0\n  mlx5e_xmit+0x1e8f/0x4190 [mlx5_core]\n  dev_hard_start_xmit+0x120/0x530\n  sch_direct_xmit+0x149/0x11e0\n  __qdisc_run+0x3ad/0x1730\n  __dev_queue_xmit+0x1196/0x2ed0\n  vlan_dev_hard_start_xmit+0x32e/0x510 [8021q]\n  dev_hard_start_xmit+0x120/0x530\n  __dev_queue_xmit+0x14a7/0x2ed0\n  macsec_start_xmit+0x13e9/0x2340\n  dev_hard_start_xmit+0x120/0x530\n  __dev_queue_xmit+0x14a7/0x2ed0\n  ip6_finish_output2+0x923/0x1a70\n  ip6_finish_output+0x2d7/0x970\n  ip6_output+0x1ce/0x3a0\n  NF_HOOK.constprop.0+0x15f/0x190\n  mld_sendpack+0x59a/0xbd0\n  mld_ifc_work+0x48a/0xa80\n  process_one_work+0x5aa/0xe50\n  worker_thread+0x79c/0x1290\n  kthread+0x28f/0x350\n  ret_from_fork+0x2d/0x70\n  ret_from_fork_asm+0x11/0x20\n  </TASK>\n\n Allocated by task 3922:\n  kasan_save_stack+0x20/0x40\n  kasan_save_track+0x10/0x30\n  __kasan_kmalloc+0x77/0x90\n  __kmalloc_noprof+0x188/0x400\n  metadata_dst_alloc+0x1f/0x4e0\n  macsec_newlink+0x914/0x1410\n  __rtnl_newlink+0xe08/0x15b0\n  rtnl_newlink+0x5f/0x90\n  rtnetlink_rcv_msg+0x667/0xa80\n  netlink_rcv_skb+0x12c/0x360\n  netlink_unicast+0x551/0x770\n  netlink_sendmsg+0x72d/0xbd0\n  __sock_sendmsg+0xc5/0x190\n  ____sys_sendmsg+0x52e/0x6a0\n  ___sys_sendmsg+0xeb/0x170\n  __sys_sendmsg+0xb5/0x140\n  do_syscall_64+0x4c/0x100\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n Freed by task 4011:\n  kasan_save_stack+0x20/0x40\n  kasan_save_track+0x10/0x30\n  kasan_save_free_info+0x37/0x50\n  poison_slab_object+0x10c/0x190\n  __kasan_slab_free+0x11/0x30\n  kfree+0xe0/0x290\n  macsec_free_netdev+0x3f/0x140\n  netdev_run_todo+0x450/0xc70\n  rtnetlink_rcv_msg+0x66f/0xa80\n  netlink_rcv_skb+0x12c/0x360\n  netlink_unicast+0x551/0x770\n  netlink_sendmsg+0x72d/0xbd0\n  __sock_sendmsg+0xc5/0x190\n  ____sys_sendmsg+0x52e/0x6a0\n  ___sys_sendmsg+0xeb/0x170\n  __sys_sendmsg+0xb5/0x140\n  do_syscall_64+0x4c/0x100\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53","publishedAt":"2024-11-09T10:15:14.259Z","updatedAt":"2026-08-05T11:42:50.813Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"872932cf75cf859804370a265dd58118129386fa","versionType":"git"},{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"9f5ae743dbe9a2458540a7d35fff0f990df025cf","versionType":"git"},{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"4614640f1d5c93c22272117dc256e9940ccac8e8","versionType":"git"},{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"f1e54d11b210b53d418ff1476c6b58a2f434dfc0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/macsec.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.1","versionType":"semver"},{"version":"6.1.116","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.60","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.11.7","status":"unaffected","lessThanOrEqual":"6.11.*","versionType":"semver"},{"version":"6.12","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/macsec.c"]}],"references":["https://git.kernel.org/stable/c/872932cf75cf859804370a265dd58118129386fa","https://git.kernel.org/stable/c/9f5ae743dbe9a2458540a7d35fff0f990df025cf","https://git.kernel.org/stable/c/4614640f1d5c93c22272117dc256e9940ccac8e8","https://git.kernel.org/stable/c/f1e54d11b210b53d418ff1476c6b58a2f434dfc0","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:07:56.516Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/50xxx/CVE-2024-50261.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-50261","state":"PUBLISHED","datePublished":"2024-11-09T10:15:14.259Z","dateUpdated":"2026-08-05T11:42:50.813Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-10-21T19:36:19.981Z"},"containers":{"cna":{"title":"macsec: Fix use-after-free while sending the offloading packet","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: Fix use-after-free while sending the offloading packet\n\nKASAN reports the following UAF. The metadata_dst, which is used to\nstore the SCI value for macsec offload, is already freed by\nmetadata_dst_free() in macsec_free_netdev(), while driver still use it\nfor sending the packet.\n\nTo fix this issue, dst_release() is used instead to release\nmetadata_dst. So it is not freed instantly in macsec_free_netdev() if\nstill referenced by skb.\n\n BUG: KASAN: slab-use-after-free in mlx5e_xmit+0x1e8f/0x4190 [mlx5_core]\n Read of size 2 at addr ffff88813e42e038 by task kworker/7:2/714\n [...]\n Workqueue: mld mld_ifc_work\n Call Trace:\n  <TASK>\n  dump_stack_lvl+0x51/0x60\n  print_report+0xc1/0x600\n  kasan_report+0xab/0xe0\n  mlx5e_xmit+0x1e8f/0x4190 [mlx5_core]\n  dev_hard_start_xmit+0x120/0x530\n  sch_direct_xmit+0x149/0x11e0\n  __qdisc_run+0x3ad/0x1730\n  __dev_queue_xmit+0x1196/0x2ed0\n  vlan_dev_hard_start_xmit+0x32e/0x510 [8021q]\n  dev_hard_start_xmit+0x120/0x530\n  __dev_queue_xmit+0x14a7/0x2ed0\n  macsec_start_xmit+0x13e9/0x2340\n  dev_hard_start_xmit+0x120/0x530\n  __dev_queue_xmit+0x14a7/0x2ed0\n  ip6_finish_output2+0x923/0x1a70\n  ip6_finish_output+0x2d7/0x970\n  ip6_output+0x1ce/0x3a0\n  NF_HOOK.constprop.0+0x15f/0x190\n  mld_sendpack+0x59a/0xbd0\n  mld_ifc_work+0x48a/0xa80\n  process_one_work+0x5aa/0xe50\n  worker_thread+0x79c/0x1290\n  kthread+0x28f/0x350\n  ret_from_fork+0x2d/0x70\n  ret_from_fork_asm+0x11/0x20\n  </TASK>\n\n Allocated by task 3922:\n  kasan_save_stack+0x20/0x40\n  kasan_save_track+0x10/0x30\n  __kasan_kmalloc+0x77/0x90\n  __kmalloc_noprof+0x188/0x400\n  metadata_dst_alloc+0x1f/0x4e0\n  macsec_newlink+0x914/0x1410\n  __rtnl_newlink+0xe08/0x15b0\n  rtnl_newlink+0x5f/0x90\n  rtnetlink_rcv_msg+0x667/0xa80\n  netlink_rcv_skb+0x12c/0x360\n  netlink_unicast+0x551/0x770\n  netlink_sendmsg+0x72d/0xbd0\n  __sock_sendmsg+0xc5/0x190\n  ____sys_sendmsg+0x52e/0x6a0\n  ___sys_sendmsg+0xeb/0x170\n  __sys_sendmsg+0xb5/0x140\n  do_syscall_64+0x4c/0x100\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n Freed by task 4011:\n  kasan_save_stack+0x20/0x40\n  kasan_save_track+0x10/0x30\n  kasan_save_free_info+0x37/0x50\n  poison_slab_object+0x10c/0x190\n  __kasan_slab_free+0x11/0x30\n  kfree+0xe0/0x290\n  macsec_free_netdev+0x3f/0x140\n  netdev_run_todo+0x450/0xc70\n  rtnetlink_rcv_msg+0x66f/0xa80\n  netlink_rcv_skb+0x12c/0x360\n  netlink_unicast+0x551/0x770\n  netlink_sendmsg+0x72d/0xbd0\n  __sock_sendmsg+0xc5/0x190\n  ____sys_sendmsg+0x52e/0x6a0\n  ___sys_sendmsg+0xeb/0x170\n  __sys_sendmsg+0xb5/0x140\n  do_syscall_64+0x4c/0x100\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"872932cf75cf859804370a265dd58118129386fa","versionType":"git"},{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"9f5ae743dbe9a2458540a7d35fff0f990df025cf","versionType":"git"},{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"4614640f1d5c93c22272117dc256e9940ccac8e8","versionType":"git"},{"version":"0a28bfd4971fd570d1f3e4653b21415becefc92c","status":"affected","lessThan":"f1e54d11b210b53d418ff1476c6b58a2f434dfc0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/macsec.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.1","versionType":"semver"},{"version":"6.1.116","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.60","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.11.7","status":"unaffected","lessThanOrEqual":"6.11.*","versionType":"semver"},{"version":"6.12","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/macsec.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/872932cf75cf859804370a265dd58118129386fa"},{"url":"https://git.kernel.org/stable/c/9f5ae743dbe9a2458540a7d35fff0f990df025cf"},{"url":"https://git.kernel.org/stable/c/4614640f1d5c93c22272117dc256e9940ccac8e8"},{"url":"https://git.kernel.org/stable/c/f1e54d11b210b53d418ff1476c6b58a2f434dfc0"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Triggering requires local rtnetlink/genetlink operations (creating a MACsec device with HW offload, transmitting through it, then deleting it), which are not reachable from a remote peer. No packet received from the network can drive the free side of the race.\nAC:L - The attacker controls both sides of the race — it queues the offloaded skbs that take the md_dst reference and it issues the RTM_DELLINK that frees the object, and can widen the window arbitrarily with a deep or rate-limited qdisc on the real device. The upstream report shows the UAF firing from ordinary incidental MLD traffic with no deliberate racing at all.\nPR:L - Only CAP_NET_ADMIN in the owning network namespace is needed, which an unprivileged user obtains via `unshare -Urn`, and in the SR-IOV/delegated-port container deployments where MACsec offload is deployed the container holds CAP_NET_ADMIN over an offload-capable NIC. No real root in the init namespace is required.\nUI:N - The attacker performs the link creation, traffic generation and deletion entirely on its own; no victim action is involved. The published reproducer triggered on kernel-generated MLD traffic with no user involvement whatsoever.\nS:U - The freed metadata_dst and all resulting corruption live in kernel slab memory within the same security authority; no VM, IOMMU, or hypervisor boundary is crossed.\nC:H - The driver reads the freed object's type/SCI fields directly, and the deferred `dst_release()` path dereferences `dst->ops` and `dst->dev` out of reallocatable slab memory, giving an attacker who grooms the freed slot a read primitive over kernel memory. Per kernel scoring guidance a use-after-free of a heap object is High.\nI:H - `rcuref_put()` performs an atomic read-modify-write into the freed object, `call_rcu_hurry()` writes and links the freed object's rcu_head, and `dst_destroy()` makes an indirect call through `dst->ops->destroy` read from attacker-reallocatable memory — a write plus control-flow hijack primitive. A stale SCI also causes frames to be offloaded under the wrong SecY, corrupting the protected link's association.\nA:H - The confirmed KASAN slab-use-after-free in the TX fast path, the refcount corruption, and the bogus RCU callback queued on freed memory readily produce an oops or panic on a live networking path. Any use-after-free is scored High for availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:42:50.813Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.1.116"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.6.60"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.11.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.12"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.8,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"id":"CVE-2024-50261","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2024-12-11T14:25:36.484321Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-12-11T14:58:32.434Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:27:40.612Z"}}]}}}