{ "dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": { "cveId": "CVE-2024-41010", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-07-12T12:17:45.610Z", "datePublished": "2024-07-17T06:10:12.051Z", "dateUpdated": "2024-09-11T17:34:06.652Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-07-18T11:41:41.025Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix too early release of tcx_entry\n\nPedro Pinto and later independently also Hyunwoo Kim and Wongi Lee reported\nan issue that the tcx_entry can be released too early leading to a use\nafter free (UAF) when an active old-style ingress or clsact qdisc with a\nshared tc block is later replaced by another ingress or clsact instance.\n\nEssentially, the sequence to trigger the UAF (one example) can be as follows:\n\n 1. A network namespace is created\n 2. An ingress qdisc is created. This allocates a tcx_entry, and\n &tcx_entry->miniq is stored in the qdisc's miniqp->p_miniq. At the\n same time, a tcf block with index 1 is created.\n 3. chain0 is attached to the tcf block. chain0 must be connected to\n the block linked to the ingress qdisc to later reach the function\n tcf_chain0_head_change_cb_del() which triggers the UAF.\n 4. Create and graft a clsact qdisc. This causes the ingress qdisc\n created in step 1 to be removed, thus freeing the previously linked\n tcx_entry:\n\n rtnetlink_rcv_msg()\n => tc_modify_qdisc()\n => qdisc_create()\n => clsact_init() [a]\n => qdisc_graft()\n => qdisc_destroy()\n => __qdisc_destroy()\n => ingress_destroy() [b]\n => tcx_entry_free()\n => kfree_rcu() // tcx_entry freed\n\n 5. Finally, the network namespace is closed. This registers the\n cleanup_net worker, and during the process of releasing the\n remaining clsact qdisc, it accesses the tcx_entry that was\n already freed in step 4, causing the UAF to occur:\n\n cleanup_net()\n => ops_exit_list()\n => default_device_exit_batch()\n => unregister_netdevice_many()\n => unregister_netdevice_many_notify()\n => dev_shutdown()\n => qdisc_put()\n => clsact_destroy() [c]\n => tcf_block_put_ext()\n => tcf_chain0_head_change_cb_del()\n => tcf_chain_head_change_item()\n => clsact_chain_head_change()\n => mini_qdisc_pair_swap() // UAF\n\nThere are also other variants, the gist is to add an ingress (or clsact)\nqdisc with a specific shared block, then to replace that qdisc, waiting\nfor the tcx_entry kfree_rcu() to be executed and subsequently accessing\nthe current active qdisc's miniq one way or another.\n\nThe correct fix is to turn the miniq_active boolean into a counter. What\ncan be observed, at step 2 above, the counter transitions from 0->1, at\nstep [a] from 1->2 (in order for the miniq object to remain active during\nthe replacement), then in [b] from 2->1 and finally [c] 1->0 with the\neventual release. The reference counter in general ranges from [0,2] and\nit does not need to be atomic since all access to the counter is protected\nby the rtnl mutex. With this in place, there is no longer a UAF happening\nand the tcx_entry is freed at the correct time." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/tcx.h", "net/sched/sch_ingress.c" ], "versions": [ { "version": "e420bed02507", "lessThan": "230bb13650b0", "status": "affected", "versionType": "git" }, { "version": "e420bed02507", "lessThan": "f61ecf1bd5b5", "status": "affected", "versionType": "git" }, { "version": "e420bed02507", "lessThan": "1cb6f0bae504", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/tcx.h", "net/sched/sch_ingress.c" ], "versions": [ { "version": "6.6", "status": "affected" }, { "version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.41", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.9.10", "lessThanOrEqual": "6.9.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.10", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/230bb13650b0f186f540500fd5f5f7096a822a2a" }, { "url": "https://git.kernel.org/stable/c/f61ecf1bd5b562ebfd7d430ccb31619857e80857" }, { "url": "https://git.kernel.org/stable/c/1cb6f0bae50441f4b4b32a28315853b279c7404e" } ], "title": "bpf: Fix too early release of tcx_entry", "x_generator": { "engine": "bippy-c9c4e1df01b2" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T04:39:55.990Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/230bb13650b0f186f540500fd5f5f7096a822a2a", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/f61ecf1bd5b562ebfd7d430ccb31619857e80857", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/1cb6f0bae50441f4b4b32a28315853b279c7404e", "tags": [ "x_transferred" ] } ] }, { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-41010", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:25:09.492833Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-11T17:34:06.652Z" } } ] } }