{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nethtool: do not perform operations on net devices being unregistered\n\nThere is a short period between a net device starts to be unregistered\nand when it is actually gone. In that time frame ethtool operations\ncould still be performed, which might end up in unwanted or undefined\nbehaviours[1].\n\nDo not allow ethtool operations after a net device starts its\nunregistration. This patch targets the netlink part as the ioctl one\nisn't affected: the reference to the net device is taken and the\noperation is executed within an rtnl lock section and the net device\nwon't be found after unregister.\n\n[1] For example adding Tx queues after unregister ends up in NULL\n    pointer exceptions and UaFs, such as:\n\n      BUG: KASAN: use-after-free in kobject_get+0x14/0x90\n      Read of size 1 at addr ffff88801961248c by task ethtool/755\n\n      CPU: 0 PID: 755 Comm: ethtool Not tainted 5.15.0-rc6+ #778\n      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/014\n      Call Trace:\n       dump_stack_lvl+0x57/0x72\n       print_address_description.constprop.0+0x1f/0x140\n       kasan_report.cold+0x7f/0x11b\n       kobject_get+0x14/0x90\n       kobject_add_internal+0x3d1/0x450\n       kobject_init_and_add+0xba/0xf0\n       netdev_queue_update_kobjects+0xcf/0x200\n       netif_set_real_num_tx_queues+0xb4/0x310\n       veth_set_channels+0x1c3/0x550\n       ethnl_set_channels+0x524/0x610"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/ethtool/netlink.c"
               ],
               "versions": [
                  {
                     "version": "041b1c5d4a53",
                     "lessThan": "7c26da3be1e9",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "041b1c5d4a53",
                     "lessThan": "cfd719f04267",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "041b1c5d4a53",
                     "lessThan": "dde91ccfa25f",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "net/ethtool/netlink.c"
               ],
               "versions": [
                  {
                     "version": "5.6",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.6",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.87",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.8",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.16",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/7c26da3be1e9843a15b5318f90db8a564479d2ac"
            },
            {
               "url": "https://git.kernel.org/stable/c/cfd719f04267108f5f5bf802b9d7de69e99a99f9"
            },
            {
               "url": "https://git.kernel.org/stable/c/dde91ccfa25fd58f64c397d91b81a4b393100ffa"
            }
         ],
         "title": "ethtool: do not perform operations on net devices being unregistered",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47517",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}