{"api_version":"1","generated_at":"2026-07-25T00:50:00+00:00","cve":"CVE-2026-63815","urls":{"html":"https://cve.report/CVE-2026-63815","api":"https://cve.report/api/cve/CVE-2026-63815.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63815","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63815"},"summary":{"title":"f2fs: bound i_inline_xattr_size for non-inline-xattr inodes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: bound i_inline_xattr_size for non-inline-xattr inodes\n\nWhen the flexible_inline_xattr feature is enabled, do_read_inode() loads\nthe on-disk i_inline_xattr_size unconditionally:\n\n\tif (f2fs_sb_has_flexible_inline_xattr(sbi))\n\t\tfi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size);\n\nbut sanity_check_inode() only range-checks it when the inode also has the\nFI_INLINE_XATTR flag set.  An inode that carries an inline dentry or inline\ndata but not FI_INLINE_XATTR -- the normal layout for an inline\ndirectory -- therefore keeps a fully attacker-controlled\ni_inline_xattr_size from a crafted image.\n\nget_inline_xattr_addrs() returns that value with no flag gating, so it\nfeeds the inode geometry:\n\n\tMAX_INLINE_DATA()  = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1)\n\tNR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...)\n\taddrs_per_page()   = CUR_ADDRS_PER_INODE - i_inline_xattr_size\n\nA large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY()\nnegative, so make_dentry_ptr_inline() sets d->max (int) to a negative\nvalue.  The inline directory walk then compares an unsigned long bit_pos\nagainst that negative d->max, which is promoted to a huge unsigned bound,\nand reads far past the inline area:\n\n\twhile (bit_pos < d->max)\t\t/* fs/f2fs/dir.c */\n\t\t... test_bit_le(bit_pos, d->bitmap) / d->dentry[bit_pos] ...\n\nMounting a crafted image and reading such a directory triggers an\nout-of-bounds read in f2fs_fill_dentries(); the same underflow also\ncorrupts ADDRS_PER_INODE for regular files.\n\nValidate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the\nflexible_inline_xattr feature is enabled -- i.e. whenever the value is\nloaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE\nbound gated on inodes that actually carry an inline xattr, so legitimate\ninodes with i_inline_xattr_size == 0 are still accepted.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 12:16:54","updated_at":"2026-07-24 15:19:04"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/a08ee30dcbeff6b97df75c38c2589603ddde53a6","name":"https://git.kernel.org/stable/c/a08ee30dcbeff6b97df75c38c2589603ddde53a6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3c8d6b4093aea40a20596f452289e7c22d84e6d5","name":"https://git.kernel.org/stable/c/3c8d6b4093aea40a20596f452289e7c22d84e6d5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/76e1a05cf6d4051931d7fa4ead51a05786a62918","name":"https://git.kernel.org/stable/c/76e1a05cf6d4051931d7fa4ead51a05786a62918","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706","name":"https://git.kernel.org/stable/c/2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/16bc237ce3c483b75575abea53cfb639745311ed","name":"https://git.kernel.org/stable/c/16bc237ce3c483b75575abea53cfb639745311ed","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/378acf3cf19b6af6cba55e8dd1154c4e1504bae8","name":"https://git.kernel.org/stable/c/378acf3cf19b6af6cba55e8dd1154c4e1504bae8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d","name":"https://git.kernel.org/stable/c/4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c3e05522daae4e7348a1ea81eeb321d25aa0fd3b","name":"https://git.kernel.org/stable/c/c3e05522daae4e7348a1ea81eeb321d25aa0fd3b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63815","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63815","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6afc662e68b5f988282ff20afd58a89b1c279dca 3c8d6b4093aea40a20596f452289e7c22d84e6d5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6afc662e68b5f988282ff20afd58a89b1c279dca a08ee30dcbeff6b97df75c38c2589603ddde53a6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6afc662e68b5f988282ff20afd58a89b1c279dca c3e05522daae4e7348a1ea81eeb321d25aa0fd3b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6afc662e68b5f988282ff20afd58a89b1c279dca 76e1a05cf6d4051931d7fa4ead51a05786a62918 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.96 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.39 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.3 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63815","cve":"CVE-2026-63815","epss":"0.001320000","percentile":"0.031530000","score_date":"2026-07-24","updated_at":"2026-07-25 00:02:51"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/f2fs/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"3c8d6b4093aea40a20596f452289e7c22d84e6d5","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"a08ee30dcbeff6b97df75c38c2589603ddde53a6","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"c3e05522daae4e7348a1ea81eeb321d25aa0fd3b","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"76e1a05cf6d4051931d7fa4ead51a05786a62918","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"16bc237ce3c483b75575abea53cfb639745311ed","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"},{"lessThan":"378acf3cf19b6af6cba55e8dd1154c4e1504bae8","status":"affected","version":"6afc662e68b5f988282ff20afd58a89b1c279dca","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/f2fs/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.15"},{"lessThan":"4.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.261","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.96","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.39","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.261","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.96","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.39","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.3","versionStartIncluding":"4.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"4.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: bound i_inline_xattr_size for non-inline-xattr inodes\n\nWhen the flexible_inline_xattr feature is enabled, do_read_inode() loads\nthe on-disk i_inline_xattr_size unconditionally:\n\n\tif (f2fs_sb_has_flexible_inline_xattr(sbi))\n\t\tfi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size);\n\nbut sanity_check_inode() only range-checks it when the inode also has the\nFI_INLINE_XATTR flag set.  An inode that carries an inline dentry or inline\ndata but not FI_INLINE_XATTR -- the normal layout for an inline\ndirectory -- therefore keeps a fully attacker-controlled\ni_inline_xattr_size from a crafted image.\n\nget_inline_xattr_addrs() returns that value with no flag gating, so it\nfeeds the inode geometry:\n\n\tMAX_INLINE_DATA()  = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1)\n\tNR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...)\n\taddrs_per_page()   = CUR_ADDRS_PER_INODE - i_inline_xattr_size\n\nA large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY()\nnegative, so make_dentry_ptr_inline() sets d->max (int) to a negative\nvalue.  The inline directory walk then compares an unsigned long bit_pos\nagainst that negative d->max, which is promoted to a huge unsigned bound,\nand reads far past the inline area:\n\n\twhile (bit_pos < d->max)\t\t/* fs/f2fs/dir.c */\n\t\t... test_bit_le(bit_pos, d->bitmap) / d->dentry[bit_pos] ...\n\nMounting a crafted image and reading such a directory triggers an\nout-of-bounds read in f2fs_fill_dentries(); the same underflow also\ncorrupts ADDRS_PER_INODE for regular files.\n\nValidate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the\nflexible_inline_xattr feature is enabled -- i.e. whenever the value is\nloaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE\nbound gated on inodes that actually carry an inline xattr, so legitimate\ninodes with i_inline_xattr_size == 0 are still accepted."}],"metrics":[{"cvssV3_1":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-24T14:34:08.336Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/3c8d6b4093aea40a20596f452289e7c22d84e6d5"},{"url":"https://git.kernel.org/stable/c/a08ee30dcbeff6b97df75c38c2589603ddde53a6"},{"url":"https://git.kernel.org/stable/c/c3e05522daae4e7348a1ea81eeb321d25aa0fd3b"},{"url":"https://git.kernel.org/stable/c/76e1a05cf6d4051931d7fa4ead51a05786a62918"},{"url":"https://git.kernel.org/stable/c/2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706"},{"url":"https://git.kernel.org/stable/c/4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d"},{"url":"https://git.kernel.org/stable/c/16bc237ce3c483b75575abea53cfb639745311ed"},{"url":"https://git.kernel.org/stable/c/378acf3cf19b6af6cba55e8dd1154c4e1504bae8"}],"title":"f2fs: bound i_inline_xattr_size for non-inline-xattr inodes","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63815","datePublished":"2026-07-19T12:02:15.345Z","dateReserved":"2026-07-19T07:54:57.014Z","dateUpdated":"2026-07-24T14:34:08.336Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 12:16:54","lastModifiedDate":"2026-07-24 15:19:04","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.5,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63815","Ordinal":"1","Title":"f2fs: bound i_inline_xattr_size for non-inline-xattr inodes","CVE":"CVE-2026-63815","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63815","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: bound i_inline_xattr_size for non-inline-xattr inodes\n\nWhen the flexible_inline_xattr feature is enabled, do_read_inode() loads\nthe on-disk i_inline_xattr_size unconditionally:\n\n\tif (f2fs_sb_has_flexible_inline_xattr(sbi))\n\t\tfi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size);\n\nbut sanity_check_inode() only range-checks it when the inode also has the\nFI_INLINE_XATTR flag set.  An inode that carries an inline dentry or inline\ndata but not FI_INLINE_XATTR -- the normal layout for an inline\ndirectory -- therefore keeps a fully attacker-controlled\ni_inline_xattr_size from a crafted image.\n\nget_inline_xattr_addrs() returns that value with no flag gating, so it\nfeeds the inode geometry:\n\n\tMAX_INLINE_DATA()  = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1)\n\tNR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...)\n\taddrs_per_page()   = CUR_ADDRS_PER_INODE - i_inline_xattr_size\n\nA large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY()\nnegative, so make_dentry_ptr_inline() sets d->max (int) to a negative\nvalue.  The inline directory walk then compares an unsigned long bit_pos\nagainst that negative d->max, which is promoted to a huge unsigned bound,\nand reads far past the inline area:\n\n\twhile (bit_pos < d->max)\t\t/* fs/f2fs/dir.c */\n\t\t... test_bit_le(bit_pos, d->bitmap) / d->dentry[bit_pos] ...\n\nMounting a crafted image and reading such a directory triggers an\nout-of-bounds read in f2fs_fill_dentries(); the same underflow also\ncorrupts ADDRS_PER_INODE for regular files.\n\nValidate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the\nflexible_inline_xattr feature is enabled -- i.e. whenever the value is\nloaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE\nbound gated on inodes that actually carry an inline xattr, so legitimate\ninodes with i_inline_xattr_size == 0 are still accepted.","Type":"Description","Title":"f2fs: bound i_inline_xattr_size for non-inline-xattr inodes"}]}}}