cve/published/2025/CVE-2025-21643.json

{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix kernel async DIO\n\nNetfslib needs to be able to handle kernel-initiated asynchronous DIO that\nis supplied with a bio_vec[] array.  Currently, because of the async flag,\nthis gets passed to netfs_extract_user_iter() which throws a warning and\nfails because it only handles IOVEC and UBUF iterators.  This can be\ntriggered through a combination of cifs and a loopback blockdev with\nsomething like:\n\n        mount //my/cifs/share /foo\n        dd if=/dev/zero of=/foo/m0 bs=4K count=1K\n        losetup --sector-size 4096 --direct-io=on /dev/loop2046 /foo/m0\n        echo hello >/dev/loop2046\n\nThis causes the following to appear in syslog:\n\n        WARNING: CPU: 2 PID: 109 at fs/netfs/iterator.c:50 netfs_extract_user_iter+0x170/0x250 [netfs]\n\nand the write to fail.\n\nFix this by removing the check in netfs_unbuffered_write_iter_locked() that\ncauses async kernel DIO writes to be handled as userspace writes.  Note\nthat this change relies on the kernel caller maintaining the existence of\nthe bio_vec array (or kvec[] or folio_queue) until the op is complete."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/netfs/direct_write.c"
               ],
               "versions": [
                  {
                     "version": "153a9961b551101cd38e94e26cd92fbfd198b19b",
                     "lessThan": "9f3a265836844eda30bf34c2584b8011fd4f0f49",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "153a9961b551101cd38e94e26cd92fbfd198b19b",
                     "lessThan": "3f6bc9e3ab9b127171d39f9ac6eca1abb693b731",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/netfs/direct_write.c"
               ],
               "versions": [
                  {
                     "version": "6.8",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "6.8",
                     "status": "unaffected",
                     "versionType": "semver"
                  },
                  {
                     "version": "6.12.10",
                     "lessThanOrEqual": "6.12.*",
                     "status": "unaffected",
                     "versionType": "semver"
                  },
                  {
                     "version": "6.13",
                     "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": "6.8",
                           "versionEndExcluding": "6.12.10"
                        },
                        {
                           "vulnerable": true,
                           "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           "versionStartIncluding": "6.8",
                           "versionEndExcluding": "6.13"
                        }
                     ]
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/9f3a265836844eda30bf34c2584b8011fd4f0f49"
            },
            {
               "url": "https://git.kernel.org/stable/c/3f6bc9e3ab9b127171d39f9ac6eca1abb693b731"
            }
         ],
         "title": "netfs: Fix kernel async DIO",
         "x_generator": {
            "engine": "bippy-1.2.0"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2025-21643",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}