FKIE_CVE-2026-93235

Vulnerability from fkie_nvd - Published: 2026-09-24 16:17 - Updated: 2026-09-24 16:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to zero post-EOF data when extending file size generic/794 4s ... - output mismatch (see /share/git/fstests/results//generic/794.out.bad) --- tests/generic/794.out 2026-06-12 08:46:32.766426241 +0800 +++ /share/git/fstests/results//generic/794.out.bad 2026-07-05 18:32:55.000000000 +0800 @@ -1,4 +1,16 @@ QA output created by 794 append_write +FAIL: non-zero data in gap [4080,4096) after shutdown+remount +000000 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a >ZZZZZZZZZZZZZZZZ< +* +001000 truncate_up ... (Run 'diff -u /share/git/fstests/tests/generic/794.out /share/git/fstests/results//generic/794.out.bad' to see the entire diff) Ran: generic/794 Failures: generic/794 Failed 1 of 1 tests Steps of generic/794: 1. write 4096 bytes to file w/ 0x5a 2. use fiemap to get PBA of first block in file 3. truncate file to 4080 4. umount; write 4096 bytes to file w/ 0x5a directly via PBA; mount 5. extend filesize via a) append 4096 from offset 4096, or b) truncate 8192, or c) fallocate 4096 from offset 4096 6. verify the gap is zeroed in memory [4080,4096) 7. sync range 4096 from offset 4096; shutdown -f (flush meta before shutdown) 8. umount; mount; verify [4080,4096) is zeroed or not. When extending file size (e.g. via truncate, fallocate, or write) across an unaligned EOF boundary, we need to ensure that post-EOF data in the partial page is zeroed out in pagecache and marked dirty, then writeback the cache to persist zeroed data before committing inode w/ updated i_size. This help to prevent stale disk data beyond the previous EOF from being exposed after remounting or crash recovery. Since f2fs is a LFS filesystem, we only support direct write via PBA in pinfile, and pinfile has section-aligned filesize, so in Android, there should no problem, but for other usage in different environment, let's fix this w/ fsync_mode=strict mount option.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/32c7f11a24268ba8d3bb50ea7f54d33f698cd253
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5eced87b7d19dbc76ebdddaf322046f9ac582fcb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6882d458d2e403f6ba7b45542dd31a6b7531eb2e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/91ec55ddc097ccddd25ffb95a3d079b2ef362372
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c42608c09b6b5d5967bf211c255914c068c2cde1
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/file.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6882d458d2e403f6ba7b45542dd31a6b7531eb2e",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "32c7f11a24268ba8d3bb50ea7f54d33f698cd253",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "91ec55ddc097ccddd25ffb95a3d079b2ef362372",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "c42608c09b6b5d5967bf211c255914c068c2cde1",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "5eced87b7d19dbc76ebdddaf322046f9ac582fcb",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "6.6.157",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12.110",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "6.18.51",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "7.2.5",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/file.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to zero post-EOF data when extending file size\n\ngeneric/794  4s ... - output mismatch (see /share/git/fstests/results//generic/794.out.bad)\n    --- tests/generic/794.out   2026-06-12 08:46:32.766426241 +0800\n    +++ /share/git/fstests/results//generic/794.out.bad 2026-07-05 18:32:55.000000000 +0800\n    @@ -1,4 +1,16 @@\n     QA output created by 794\n     append_write\n    +FAIL: non-zero data in gap [4080,4096) after shutdown+remount\n    +000000 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  \u003eZZZZZZZZZZZZZZZZ\u003c\n    +*\n    +001000\n     truncate_up\n    ...\n    (Run \u0027diff -u /share/git/fstests/tests/generic/794.out /share/git/fstests/results//generic/794.out.bad\u0027  to see the entire diff)\nRan: generic/794\nFailures: generic/794\nFailed 1 of 1 tests\n\nSteps of generic/794:\n1. write 4096 bytes to file w/ 0x5a\n2. use fiemap to get PBA of first block in file\n3. truncate file to 4080\n4. umount; write 4096 bytes to file w/ 0x5a directly via PBA; mount\n5. extend filesize via\n   a) append 4096 from offset 4096, or\n   b) truncate 8192, or\n   c) fallocate 4096 from offset 4096\n6. verify the gap is zeroed in memory [4080,4096)\n7. sync range 4096 from offset 4096; shutdown -f (flush meta before shutdown)\n8. umount; mount; verify [4080,4096) is zeroed or not.\n\nWhen extending file size (e.g. via truncate, fallocate, or write) across an\nunaligned EOF boundary, we need to ensure that post-EOF data in the partial\npage is zeroed out in pagecache and marked dirty, then writeback the cache to\npersist zeroed data before committing inode w/ updated i_size.\n\nThis help to prevent stale disk data beyond the previous EOF from being exposed\nafter remounting or crash recovery.\n\nSince f2fs is a LFS filesystem, we only support direct write via PBA in pinfile,\nand pinfile has section-aligned filesize, so in Android, there should no problem,\nbut for other usage in different environment, let\u0027s fix this w/ fsync_mode=strict\nmount option."
    }
  ],
  "id": "CVE-2026-93235",
  "lastModified": "2026-09-24T16:17:19.150",
  "metrics": {},
  "published": "2026-09-24T16:17:19.150",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/32c7f11a24268ba8d3bb50ea7f54d33f698cd253"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5eced87b7d19dbc76ebdddaf322046f9ac582fcb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6882d458d2e403f6ba7b45542dd31a6b7531eb2e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/91ec55ddc097ccddd25ffb95a3d079b2ef362372"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c42608c09b6b5d5967bf211c255914c068c2cde1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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