{"id":"CVE-2026-93235","state":"PUBLISHED","title":"f2fs: fix to zero post-EOF data when extending file size","description":"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  >ZZZZZZZZZZZZZZZZ<\n    +*\n    +001000\n     truncate_up\n    ...\n    (Run 'diff -u /share/git/fstests/tests/generic/794.out /share/git/fstests/results//generic/794.out.bad'  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's fix this w/ fsync_mode=strict\nmount option.","publishedAt":"2026-09-24T15:33:33.241Z","updatedAt":"2026-10-19T09:07:46.831Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"6882d458d2e403f6ba7b45542dd31a6b7531eb2e","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"32c7f11a24268ba8d3bb50ea7f54d33f698cd253","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"91ec55ddc097ccddd25ffb95a3d079b2ef362372","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"c42608c09b6b5d5967bf211c255914c068c2cde1","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"5eced87b7d19dbc76ebdddaf322046f9ac582fcb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/file.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/file.c"]}],"references":["https://git.kernel.org/stable/c/6882d458d2e403f6ba7b45542dd31a6b7531eb2e","https://git.kernel.org/stable/c/32c7f11a24268ba8d3bb50ea7f54d33f698cd253","https://git.kernel.org/stable/c/91ec55ddc097ccddd25ffb95a3d079b2ef362372","https://git.kernel.org/stable/c/c42608c09b6b5d5967bf211c255914c068c2cde1","https://git.kernel.org/stable/c/5eced87b7d19dbc76ebdddaf322046f9ac582fcb"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/93xxx/CVE-2026-93235.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93235","state":"PUBLISHED","datePublished":"2026-09-24T15:33:33.241Z","dateUpdated":"2026-10-19T09:07:46.831Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-17T16:02:15.095Z"},"containers":{"cna":{"title":"f2fs: fix to zero post-EOF data when extending file size","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  >ZZZZZZZZZZZZZZZZ<\n    +*\n    +001000\n     truncate_up\n    ...\n    (Run 'diff -u /share/git/fstests/tests/generic/794.out /share/git/fstests/results//generic/794.out.bad'  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's fix this w/ fsync_mode=strict\nmount option."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"6882d458d2e403f6ba7b45542dd31a6b7531eb2e","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"32c7f11a24268ba8d3bb50ea7f54d33f698cd253","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"91ec55ddc097ccddd25ffb95a3d079b2ef362372","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"c42608c09b6b5d5967bf211c255914c068c2cde1","versionType":"git"},{"version":"fbfa2cc58d5363f780f4f2ad0243a47185c2bb2a","status":"affected","lessThan":"5eced87b7d19dbc76ebdddaf322046f9ac582fcb","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/file.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/file.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/6882d458d2e403f6ba7b45542dd31a6b7531eb2e"},{"url":"https://git.kernel.org/stable/c/32c7f11a24268ba8d3bb50ea7f54d33f698cd253"},{"url":"https://git.kernel.org/stable/c/91ec55ddc097ccddd25ffb95a3d079b2ef362372"},{"url":"https://git.kernel.org/stable/c/c42608c09b6b5d5967bf211c255914c068c2cde1"},{"url":"https://git.kernel.org/stable/c/5eced87b7d19dbc76ebdddaf322046f9ac582fcb"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:07:46.831Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}