| { |
| "containers": { |
| "cna": { |
| "providerMetadata": { |
| "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038" |
| }, |
| "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": "e420bed025071a623d2720a92bc2245c84757ecb", |
| "lessThan": "230bb13650b0f186f540500fd5f5f7096a822a2a", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "e420bed025071a623d2720a92bc2245c84757ecb", |
| "lessThan": "f61ecf1bd5b562ebfd7d430ccb31619857e80857", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "e420bed025071a623d2720a92bc2245c84757ecb", |
| "lessThan": "1cb6f0bae50441f4b4b32a28315853b279c7404e", |
| "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": "semver" |
| }, |
| { |
| "version": "6.6.41", |
| "lessThanOrEqual": "6.6.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.9.10", |
| "lessThanOrEqual": "6.9.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.10", |
| "lessThanOrEqual": "*", |
| "status": "unaffected", |
| "versionType": "original_commit_for_fix" |
| } |
| ] |
| } |
| ], |
| "cpeApplicability": [ |
| { |
| "nodes": [ |
| { |
| "operator": "OR", |
| "negate": false, |
| "cpeMatch": [ |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "6.6", |
| "versionEndExcluding": "6.6.41" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "6.6", |
| "versionEndExcluding": "6.9.10" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "6.6", |
| "versionEndExcluding": "6.10" |
| } |
| ] |
| } |
| ] |
| } |
| ], |
| "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-1.2.0" |
| } |
| } |
| }, |
| "cveMetadata": { |
| "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", |
| "cveID": "CVE-2024-41010", |
| "requesterUserId": "gregkh@kernel.org", |
| "serial": "1", |
| "state": "PUBLISHED" |
| }, |
| "dataType": "CVE_RECORD", |
| "dataVersion": "5.0" |
| } |
