{"id":"CVE-2025-40306","state":"PUBLISHED","title":"orangefs: fix xattr related buffer overflow...","description":"In the Linux kernel, the following vulnerability has been resolved:\n\norangefs: fix xattr related buffer overflow...\n\nWilly Tarreau <w@1wt.eu> forwarded me a message from\nDisclosure <disclosure@aisle.com> with the following\nwarning:\n\n> The helper `xattr_key()` uses the pointer variable in the loop condition\n> rather than dereferencing it. As `key` is incremented, it remains non-NULL\n> (until it runs into unmapped memory), so the loop does not terminate on\n> valid C strings and will walk memory indefinitely, consuming CPU or hanging\n> the thread.\n\nI easily reproduced this with setfattr and getfattr, causing a kernel\noops, hung user processes and corrupted orangefs files. Disclosure\nsent along a diff (not a patch) with a suggested fix, which I based\nthis patch on.\n\nAfter xattr_key started working right, xfstest generic/069 exposed an\nxattr related memory leak that lead to OOM. xattr_key returns\na hashed key.  When adding xattrs to the orangefs xattr cache, orangefs\nused hash_add, a kernel hashing macro. hash_add also hashes the key using\nhash_log which resulted in additions to the xattr cache going to the wrong\nhash bucket. generic/069 tortures a single file and orangefs does a\ngetattr for the xattr \"security.capability\" every time. Orangefs\nnegative caches on xattrs which includes a kmalloc. Since adds to the\nxattr cache were going to the wrong bucket, every getattr for\n\"security.capability\" resulted in another kmalloc, none of which were\never freed.\n\nI changed the two uses of hash_add to hlist_add_head instead\nand the memory leak ceased and generic/069 quit throwing furniture.","publishedAt":"2025-12-08T00:46:31.514Z","updatedAt":"2026-08-05T12:09:24.767Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"c6564ff6b53c9a8dc786b6f1c51ae7688273f931","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"ef892d2bf4f3fa2c8de1677dd307e678bdd3d865","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"15afebb9597449c444801d1ff0b8d8b311f950ab","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"bc812574de633cf9a9ad6974490e45f6a4bb5126","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"e09a096104fc65859422817fb2211f35855983fe","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"9127d1e90c90e5960c8bc72a4ce2c209691a7021","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"c2ca015ac109fd743fdde27933d59dc5ad46658e","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"025e880759c279ec64d0f754fe65bf45961da864","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/orangefs/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.4.302","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.247","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.197","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.159","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.117","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.58","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.8","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/orangefs/xattr.c"]}],"references":["https://git.kernel.org/stable/c/c6564ff6b53c9a8dc786b6f1c51ae7688273f931","https://git.kernel.org/stable/c/ef892d2bf4f3fa2c8de1677dd307e678bdd3d865","https://git.kernel.org/stable/c/15afebb9597449c444801d1ff0b8d8b311f950ab","https://git.kernel.org/stable/c/bc812574de633cf9a9ad6974490e45f6a4bb5126","https://git.kernel.org/stable/c/e09a096104fc65859422817fb2211f35855983fe","https://git.kernel.org/stable/c/9127d1e90c90e5960c8bc72a4ce2c209691a7021","https://git.kernel.org/stable/c/c2ca015ac109fd743fdde27933d59dc5ad46658e","https://git.kernel.org/stable/c/025e880759c279ec64d0f754fe65bf45961da864"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/40xxx/CVE-2025-40306.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40306","state":"PUBLISHED","datePublished":"2025-12-08T00:46:31.514Z","dateUpdated":"2026-08-05T12:09:24.767Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.185Z"},"containers":{"cna":{"title":"orangefs: fix xattr related buffer overflow...","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\norangefs: fix xattr related buffer overflow...\n\nWilly Tarreau <w@1wt.eu> forwarded me a message from\nDisclosure <disclosure@aisle.com> with the following\nwarning:\n\n> The helper `xattr_key()` uses the pointer variable in the loop condition\n> rather than dereferencing it. As `key` is incremented, it remains non-NULL\n> (until it runs into unmapped memory), so the loop does not terminate on\n> valid C strings and will walk memory indefinitely, consuming CPU or hanging\n> the thread.\n\nI easily reproduced this with setfattr and getfattr, causing a kernel\noops, hung user processes and corrupted orangefs files. Disclosure\nsent along a diff (not a patch) with a suggested fix, which I based\nthis patch on.\n\nAfter xattr_key started working right, xfstest generic/069 exposed an\nxattr related memory leak that lead to OOM. xattr_key returns\na hashed key.  When adding xattrs to the orangefs xattr cache, orangefs\nused hash_add, a kernel hashing macro. hash_add also hashes the key using\nhash_log which resulted in additions to the xattr cache going to the wrong\nhash bucket. generic/069 tortures a single file and orangefs does a\ngetattr for the xattr \"security.capability\" every time. Orangefs\nnegative caches on xattrs which includes a kmalloc. Since adds to the\nxattr cache were going to the wrong bucket, every getattr for\n\"security.capability\" resulted in another kmalloc, none of which were\never freed.\n\nI changed the two uses of hash_add to hlist_add_head instead\nand the memory leak ceased and generic/069 quit throwing furniture."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"c6564ff6b53c9a8dc786b6f1c51ae7688273f931","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"ef892d2bf4f3fa2c8de1677dd307e678bdd3d865","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"15afebb9597449c444801d1ff0b8d8b311f950ab","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"bc812574de633cf9a9ad6974490e45f6a4bb5126","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"e09a096104fc65859422817fb2211f35855983fe","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"9127d1e90c90e5960c8bc72a4ce2c209691a7021","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"c2ca015ac109fd743fdde27933d59dc5ad46658e","versionType":"git"},{"version":"f7ab093f74bf638ed98fd1115f3efa17e308bb7f","status":"affected","lessThan":"025e880759c279ec64d0f754fe65bf45961da864","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/orangefs/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.4.302","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.247","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.197","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.159","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.117","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.58","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.8","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/orangefs/xattr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c6564ff6b53c9a8dc786b6f1c51ae7688273f931"},{"url":"https://git.kernel.org/stable/c/ef892d2bf4f3fa2c8de1677dd307e678bdd3d865"},{"url":"https://git.kernel.org/stable/c/15afebb9597449c444801d1ff0b8d8b311f950ab"},{"url":"https://git.kernel.org/stable/c/bc812574de633cf9a9ad6974490e45f6a4bb5126"},{"url":"https://git.kernel.org/stable/c/e09a096104fc65859422817fb2211f35855983fe"},{"url":"https://git.kernel.org/stable/c/9127d1e90c90e5960c8bc72a4ce2c209691a7021"},{"url":"https://git.kernel.org/stable/c/c2ca015ac109fd743fdde27933d59dc5ad46658e"},{"url":"https://git.kernel.org/stable/c/025e880759c279ec64d0f754fe65bf45961da864"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable `xattr_key()` is reached only through local syscalls (getxattr/setxattr/removexattr, or implicit ACL and `security.capability` lookups) on a mounted OrangeFS filesystem. The xattr keys originate from local userspace or kernel .rodata, never from the OrangeFS server's network responses.\nAC:L - A single `getfattr`/`setfattr` on any file of an OrangeFS mount deterministically triggers the runaway loop; the maintainer reported reproducing it \"easily\". No race, no memory-layout precondition, and the guard-page fault on the kernel stack makes the oops essentially guaranteed.\nPR:L - Any unprivileged local user with read access to a file on the mount can trigger it; `xattr_permission()` only requires MAY_READ for the user.* namespace, and the `.prefix = \"\"` handler matches every name. The ACL/`security.capability` paths fire during ordinary permission checks and execve, needing no explicit privilege at all.\nUI:N - The attacker triggers the bug entirely through their own syscalls with no victim action required. An existing OrangeFS mount is a property of the deployment, not an action the attacker must induce a user to perform.\nS:U - The out-of-bounds read, hang, and oops all occur within the kernel of the same host, with no crossing into another security authority such as a hypervisor or IOMMU boundary.\nC:H - This is an unbounded out-of-bounds read that walks arbitrary kernel memory — live kernel stack contents, .rodata/.data, or the slab and direct map — far beyond a few bounded bytes. The resulting hash bucket (`sum % 16`) is observable to the attacker as a cache-hit/miss timing oracle over that adjacent kernel memory.\nI:H - The maintainer directly observed \"corrupted orangefs files\" when reproducing the bug, a confirmed loss of integrity of user data on a shared parallel filesystem. The broken xattr cache additionally governs POSIX ACL and `security.capability` retrieval, so mis-bucketed and stale entries can corrupt access-control and file-capability decisions.\nA:H - Confirmed kernel oops, hung user processes, and OOM from the associated unbounded kmalloc leak. The loop has no `cond_resched()` and runs with `xattr_sem` write-held in the set/remove paths, so it burns a CPU until it faults while blocking every other thread on that inode — soft lockups, RCU stalls, and hung tasks."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:09:24.767Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.4.302"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.10.247"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.15.197"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.1.159"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.6.117"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.12.58"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.17.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.18"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}