CVE-2021-47544 (GCVE-0-2021-47544)
Vulnerability from cvelistv5
Published
2024-05-24 15:09
Modified
2025-05-04 07:13
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: fix page frag corruption on page fault Steffen reported a TCP stream corruption for HTTP requests served by the apache web-server using a cifs mount-point and memory mapping the relevant file. The root cause is quite similar to the one addressed by commit 20eb4f29b602 ("net: fix sk_page_frag() recursion from memory reclaim"). Here the nested access to the task page frag is caused by a page fault on the (mmapped) user-space memory buffer coming from the cifs file. The page fault handler performs an smb transaction on a different socket, inside the same process context. Since sk->sk_allaction for such socket does not prevent the usage for the task_frag, the nested allocation modify "under the hood" the page frag in use by the outer sendmsg call, corrupting the stream. The overall relevant stack trace looks like the following: httpd 78268 [001] 3461630.850950: probe:tcp_sendmsg_locked: ffffffff91461d91 tcp_sendmsg_locked+0x1 ffffffff91462b57 tcp_sendmsg+0x27 ffffffff9139814e sock_sendmsg+0x3e ffffffffc06dfe1d smb_send_kvec+0x28 [...] ffffffffc06cfaf8 cifs_readpages+0x213 ffffffff90e83c4b read_pages+0x6b ffffffff90e83f31 __do_page_cache_readahead+0x1c1 ffffffff90e79e98 filemap_fault+0x788 ffffffff90eb0458 __do_fault+0x38 ffffffff90eb5280 do_fault+0x1a0 ffffffff90eb7c84 __handle_mm_fault+0x4d4 ffffffff90eb8093 handle_mm_fault+0xc3 ffffffff90c74f6d __do_page_fault+0x1ed ffffffff90c75277 do_page_fault+0x37 ffffffff9160111e page_fault+0x1e ffffffff9109e7b5 copyin+0x25 ffffffff9109eb40 _copy_from_iter_full+0xe0 ffffffff91462370 tcp_sendmsg_locked+0x5e0 ffffffff91462370 tcp_sendmsg_locked+0x5e0 ffffffff91462b57 tcp_sendmsg+0x27 ffffffff9139815c sock_sendmsg+0x4c ffffffff913981f7 sock_write_iter+0x97 ffffffff90f2cc56 do_iter_readv_writev+0x156 ffffffff90f2dff0 do_iter_write+0x80 ffffffff90f2e1c3 vfs_writev+0xa3 ffffffff90f2e27c do_writev+0x5c ffffffff90c042bb do_syscall_64+0x5b ffffffff916000ad entry_SYSCALL_64_after_hwframe+0x65 The cifs filesystem rightfully sets sk_allocations to GFP_NOFS, we can avoid the nesting using the sk page frag for allocation lacking the __GFP_FS flag. Do not define an additional mm-helper for that, as this is strictly tied to the sk page frag usage. v1 -> v2: - use a stricted sk_page_frag() check instead of reordering the code (Eric)
References
Impacted products
Vendor Product Version
Linux Linux Version: 5640f7685831e088fe6c2e1f863a6805962f8e81
Version: 5640f7685831e088fe6c2e1f863a6805962f8e81
Version: 5640f7685831e088fe6c2e1f863a6805962f8e81
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47544",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-05-28T17:06:35.022552Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-06-04T17:15:09.727Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:39:59.619Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/c6f340a331fb72e5ac23a083de9c780e132ca3ae"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/5a9afcd827cafe14a95c9fcbded2c2d104f18dfc"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/dacb5d8875cc6cd3a553363b4d6f06760fcbe70c"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/sock.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c6f340a331fb72e5ac23a083de9c780e132ca3ae",
              "status": "affected",
              "version": "5640f7685831e088fe6c2e1f863a6805962f8e81",
              "versionType": "git"
            },
            {
              "lessThan": "5a9afcd827cafe14a95c9fcbded2c2d104f18dfc",
              "status": "affected",
              "version": "5640f7685831e088fe6c2e1f863a6805962f8e81",
              "versionType": "git"
            },
            {
              "lessThan": "dacb5d8875cc6cd3a553363b4d6f06760fcbe70c",
              "status": "affected",
              "version": "5640f7685831e088fe6c2e1f863a6805962f8e81",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/sock.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.7"
            },
            {
              "lessThan": "3.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.84",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.16",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.84",
                  "versionStartIncluding": "3.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.7",
                  "versionStartIncluding": "3.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.16",
                  "versionStartIncluding": "3.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: fix page frag corruption on page fault\n\nSteffen reported a TCP stream corruption for HTTP requests\nserved by the apache web-server using a cifs mount-point\nand memory mapping the relevant file.\n\nThe root cause is quite similar to the one addressed by\ncommit 20eb4f29b602 (\"net: fix sk_page_frag() recursion from\nmemory reclaim\"). Here the nested access to the task page frag\nis caused by a page fault on the (mmapped) user-space memory\nbuffer coming from the cifs file.\n\nThe page fault handler performs an smb transaction on a different\nsocket, inside the same process context. Since sk-\u003esk_allaction\nfor such socket does not prevent the usage for the task_frag,\nthe nested allocation modify \"under the hood\" the page frag\nin use by the outer sendmsg call, corrupting the stream.\n\nThe overall relevant stack trace looks like the following:\n\nhttpd 78268 [001] 3461630.850950:      probe:tcp_sendmsg_locked:\n        ffffffff91461d91 tcp_sendmsg_locked+0x1\n        ffffffff91462b57 tcp_sendmsg+0x27\n        ffffffff9139814e sock_sendmsg+0x3e\n        ffffffffc06dfe1d smb_send_kvec+0x28\n        [...]\n        ffffffffc06cfaf8 cifs_readpages+0x213\n        ffffffff90e83c4b read_pages+0x6b\n        ffffffff90e83f31 __do_page_cache_readahead+0x1c1\n        ffffffff90e79e98 filemap_fault+0x788\n        ffffffff90eb0458 __do_fault+0x38\n        ffffffff90eb5280 do_fault+0x1a0\n        ffffffff90eb7c84 __handle_mm_fault+0x4d4\n        ffffffff90eb8093 handle_mm_fault+0xc3\n        ffffffff90c74f6d __do_page_fault+0x1ed\n        ffffffff90c75277 do_page_fault+0x37\n        ffffffff9160111e page_fault+0x1e\n        ffffffff9109e7b5 copyin+0x25\n        ffffffff9109eb40 _copy_from_iter_full+0xe0\n        ffffffff91462370 tcp_sendmsg_locked+0x5e0\n        ffffffff91462370 tcp_sendmsg_locked+0x5e0\n        ffffffff91462b57 tcp_sendmsg+0x27\n        ffffffff9139815c sock_sendmsg+0x4c\n        ffffffff913981f7 sock_write_iter+0x97\n        ffffffff90f2cc56 do_iter_readv_writev+0x156\n        ffffffff90f2dff0 do_iter_write+0x80\n        ffffffff90f2e1c3 vfs_writev+0xa3\n        ffffffff90f2e27c do_writev+0x5c\n        ffffffff90c042bb do_syscall_64+0x5b\n        ffffffff916000ad entry_SYSCALL_64_after_hwframe+0x65\n\nThe cifs filesystem rightfully sets sk_allocations to GFP_NOFS,\nwe can avoid the nesting using the sk page frag for allocation\nlacking the __GFP_FS flag. Do not define an additional mm-helper\nfor that, as this is strictly tied to the sk page frag usage.\n\nv1 -\u003e v2:\n - use a stricted sk_page_frag() check instead of reordering the\n   code (Eric)"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-05-04T07:13:12.226Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c6f340a331fb72e5ac23a083de9c780e132ca3ae"
        },
        {
          "url": "https://git.kernel.org/stable/c/5a9afcd827cafe14a95c9fcbded2c2d104f18dfc"
        },
        {
          "url": "https://git.kernel.org/stable/c/dacb5d8875cc6cd3a553363b4d6f06760fcbe70c"
        }
      ],
      "title": "tcp: fix page frag corruption on page fault",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47544",
    "datePublished": "2024-05-24T15:09:49.895Z",
    "dateReserved": "2024-05-24T15:02:54.829Z",
    "dateUpdated": "2025-05-04T07:13:12.226Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://git.kernel.org/stable/c/c6f340a331fb72e5ac23a083de9c780e132ca3ae\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/5a9afcd827cafe14a95c9fcbded2c2d104f18dfc\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/dacb5d8875cc6cd3a553363b4d6f06760fcbe70c\", \"tags\": [\"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-04T05:39:59.619Z\"}}, {\"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-47544\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-05-28T17:06:35.022552Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-05-28T17:06:38.931Z\"}, \"title\": \"CISA ADP Vulnrichment\"}], \"cna\": {\"title\": \"tcp: fix page frag corruption on page fault\", \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"5640f7685831e088fe6c2e1f863a6805962f8e81\", \"lessThan\": \"c6f340a331fb72e5ac23a083de9c780e132ca3ae\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"5640f7685831e088fe6c2e1f863a6805962f8e81\", \"lessThan\": \"5a9afcd827cafe14a95c9fcbded2c2d104f18dfc\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"5640f7685831e088fe6c2e1f863a6805962f8e81\", \"lessThan\": \"dacb5d8875cc6cd3a553363b4d6f06760fcbe70c\", \"versionType\": \"git\"}], \"programFiles\": [\"include/net/sock.h\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"3.7\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"3.7\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"5.10.84\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.10.*\"}, {\"status\": \"unaffected\", \"version\": \"5.15.7\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.15.*\"}, {\"status\": \"unaffected\", \"version\": \"5.16\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"include/net/sock.h\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/c6f340a331fb72e5ac23a083de9c780e132ca3ae\"}, {\"url\": \"https://git.kernel.org/stable/c/5a9afcd827cafe14a95c9fcbded2c2d104f18dfc\"}, {\"url\": \"https://git.kernel.org/stable/c/dacb5d8875cc6cd3a553363b4d6f06760fcbe70c\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\ntcp: fix page frag corruption on page fault\\n\\nSteffen reported a TCP stream corruption for HTTP requests\\nserved by the apache web-server using a cifs mount-point\\nand memory mapping the relevant file.\\n\\nThe root cause is quite similar to the one addressed by\\ncommit 20eb4f29b602 (\\\"net: fix sk_page_frag() recursion from\\nmemory reclaim\\\"). Here the nested access to the task page frag\\nis caused by a page fault on the (mmapped) user-space memory\\nbuffer coming from the cifs file.\\n\\nThe page fault handler performs an smb transaction on a different\\nsocket, inside the same process context. Since sk-\u003esk_allaction\\nfor such socket does not prevent the usage for the task_frag,\\nthe nested allocation modify \\\"under the hood\\\" the page frag\\nin use by the outer sendmsg call, corrupting the stream.\\n\\nThe overall relevant stack trace looks like the following:\\n\\nhttpd 78268 [001] 3461630.850950:      probe:tcp_sendmsg_locked:\\n        ffffffff91461d91 tcp_sendmsg_locked+0x1\\n        ffffffff91462b57 tcp_sendmsg+0x27\\n        ffffffff9139814e sock_sendmsg+0x3e\\n        ffffffffc06dfe1d smb_send_kvec+0x28\\n        [...]\\n        ffffffffc06cfaf8 cifs_readpages+0x213\\n        ffffffff90e83c4b read_pages+0x6b\\n        ffffffff90e83f31 __do_page_cache_readahead+0x1c1\\n        ffffffff90e79e98 filemap_fault+0x788\\n        ffffffff90eb0458 __do_fault+0x38\\n        ffffffff90eb5280 do_fault+0x1a0\\n        ffffffff90eb7c84 __handle_mm_fault+0x4d4\\n        ffffffff90eb8093 handle_mm_fault+0xc3\\n        ffffffff90c74f6d __do_page_fault+0x1ed\\n        ffffffff90c75277 do_page_fault+0x37\\n        ffffffff9160111e page_fault+0x1e\\n        ffffffff9109e7b5 copyin+0x25\\n        ffffffff9109eb40 _copy_from_iter_full+0xe0\\n        ffffffff91462370 tcp_sendmsg_locked+0x5e0\\n        ffffffff91462370 tcp_sendmsg_locked+0x5e0\\n        ffffffff91462b57 tcp_sendmsg+0x27\\n        ffffffff9139815c sock_sendmsg+0x4c\\n        ffffffff913981f7 sock_write_iter+0x97\\n        ffffffff90f2cc56 do_iter_readv_writev+0x156\\n        ffffffff90f2dff0 do_iter_write+0x80\\n        ffffffff90f2e1c3 vfs_writev+0xa3\\n        ffffffff90f2e27c do_writev+0x5c\\n        ffffffff90c042bb do_syscall_64+0x5b\\n        ffffffff916000ad entry_SYSCALL_64_after_hwframe+0x65\\n\\nThe cifs filesystem rightfully sets sk_allocations to GFP_NOFS,\\nwe can avoid the nesting using the sk page frag for allocation\\nlacking the __GFP_FS flag. Do not define an additional mm-helper\\nfor that, as this is strictly tied to the sk page frag usage.\\n\\nv1 -\u003e v2:\\n - use a stricted sk_page_frag() check instead of reordering the\\n   code (Eric)\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.10.84\", \"versionStartIncluding\": \"3.7\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.15.7\", \"versionStartIncluding\": \"3.7\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.16\", \"versionStartIncluding\": \"3.7\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2025-05-04T07:13:12.226Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-47544\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-05-04T07:13:12.226Z\", \"dateReserved\": \"2024-05-24T15:02:54.829Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-05-24T15:09:49.895Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.