{"id":"CVE-2026-53392","revision":"d86f964d9c91477db90587dc31242247","records":[{"revision":"d86f964d9c91477db90587dc31242247","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53392","aliases":[],"title":"NFSv4/flexfiles: reject zero filehandle version count","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4/flexfiles: reject zero filehandle version count\n\nff_layout_alloc_lseg() decodes the filehandle-version array count\nfrom the flexfiles layout body. The value is used as the count for\nkzalloc_objs(), and the current code only rejects NULL.\n\nA zero count yields ZERO_SIZE_PTR, which can be stored in\ndss_info->fh_versions even though later flexfiles paths assume that at\nleast one filehandle version exists.\n\nReject fh_count == 0 before the allocation, matching the existing zero\nversion_count validation in the flexfiles GETDEVICEINFO parser.\n\nA QEMU/KASAN run with a malformed flexfiles layout hit:\n\n  KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\n  RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750\n  ff_layout_encode_layoutreturn+0x683/0x970\n  nfs4_xdr_enc_layoutreturn+0x278/0x3a0\n  Kernel panic - not syncing: Fatal exception\n\nThe patched kernel rejects the malformed layout without KASAN/oops/panic,\nand a valid fh_count=1 regression still opens, reads, and unmounts cleanly.","state":0,"publishedAt":"2026-07-19T12:01:56.101+00:00","modifiedAt":"2026-10-19T20:07:46.094+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfs/flexfilelayout/flexfilelayout.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"9033591535c066726f5b505126ccb4068b98fa4f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"18cc6d57a14fa65ab2a2b52279f549041c4bc9cf\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"be7829715e341b42846437dd9e721005db59f0cc\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"eeabb9020721db6bc132e68eeae380b8d4fb4b04\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"7779c85028a0676fb190cde4f0c540f4f8e97761\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"d8c90c7cc061265d5f2813a1f5c82ef2f4707e67\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"2131ed64b767ffa8bcdb3677d90f3964e39aabc8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d67ae825a59d639e4d8b82413af84d854617a87e\",\n                            \"lessThan\": \"2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfs/flexfilelayout/flexfilelayout.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.96\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.38\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.3\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/9033591535c066726f5b505126ccb4068b98fa4f","https://git.kernel.org/stable/c/18cc6d57a14fa65ab2a2b52279f549041c4bc9cf","https://git.kernel.org/stable/c/be7829715e341b42846437dd9e721005db59f0cc","https://git.kernel.org/stable/c/eeabb9020721db6bc132e68eeae380b8d4fb4b04","https://git.kernel.org/stable/c/7779c85028a0676fb190cde4f0c540f4f8e97761","https://git.kernel.org/stable/c/d8c90c7cc061265d5f2813a1f5c82ef2f4707e67","https://git.kernel.org/stable/c/2131ed64b767ffa8bcdb3677d90f3964e39aabc8","https://git.kernel.org/stable/c/2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53392","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53392","identifiers":["CVE-2026-53392"]},"retained":false,"historicalAffected":[]}],"coverage":[]}