{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Fix use-after-free after the TLS device goes down and up\n\nWhen a netdev with active TLS offload goes down, tls_device_down is\ncalled to stop the offload and tear down the TLS context. However, the\nsocket stays alive, and it still points to the TLS context, which is now\ndeallocated. If a netdev goes up, while the connection is still active,\nand the data flow resumes after a number of TCP retransmissions, it will\nlead to a use-after-free of the TLS context.\n\nThis commit addresses this bug by keeping the context alive until its\nnormal destruction, and implements the necessary fallbacks, so that the\nconnection can resume in software (non-offloaded) kTLS mode.\n\nOn the TX side tls_sw_fallback is used to encrypt all packets. The RX\nside already has all the necessary fallbacks, because receiving\nnon-decrypted packets is supported. The thing needed on the RX side is\nto block resync requests, which are normally produced after receiving\nnon-decrypted packets.\n\nThe necessary synchronization is implemented for a graceful teardown:\nfirst the fallbacks are deployed, then the driver resources are released\n(it used to be possible to have a tls_dev_resync after tls_dev_del).\n\nA new flag called TLS_RX_DEV_DEGRADED is added to indicate the fallback\nmode. It's used to skip the RX resync logic completely, as it becomes\nuseless, and some objects may be released (for example, resync_async,\nwhich is allocated and freed by the driver)."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "include/net/tls.h",
                  "net/tls/tls_device.c",
                  "net/tls/tls_device_fallback.c",
                  "net/tls/tls_main.c"
               ],
               "versions": [
                  {
                     "version": "e8f69799810c",
                     "lessThan": "f1d4184f128d",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "e8f69799810c",
                     "lessThan": "0f1e6fe66977",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "e8f69799810c",
                     "lessThan": "c55dcdd435aa",
                     "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/tls.h",
                  "net/tls/tls_device.c",
                  "net/tls/tls_device_fallback.c",
                  "net/tls/tls_main.c"
               ],
               "versions": [
                  {
                     "version": "4.18",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "4.18",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.43",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.12.10",
                     "lessThanOrEqual": "5.12.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.13",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/f1d4184f128dede82a59a841658ed40d4e6d3aa2"
            },
            {
               "url": "https://git.kernel.org/stable/c/0f1e6fe66977a864fe850522316f713d7b926fd9"
            },
            {
               "url": "https://git.kernel.org/stable/c/c55dcdd435aa6c6ad6ccac0a4c636d010ee367a4"
            }
         ],
         "title": "net/tls: Fix use-after-free after the TLS device goes down and up",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47131",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}