{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38382","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T04:51:24.010Z","datePublished":"2025-07-25T12:53:23.665Z","dateUpdated":"2026-08-05T12:01:29.887Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:01:29.887Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix iteration of extrefs during log replay\n\nAt __inode_add_ref() when processing extrefs, if we jump into the next\nlabel we have an undefined value of victim_name.len, since we haven't\ninitialized it before we did the goto. This results in an invalid memory\naccess in the next iteration of the loop since victim_name.len was not\ninitialized to the length of the name of the current extref.\n\nFix this by initializing victim_name.len with the current extref's name\nlength."}],"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 code is only reached through tree-log replay during `mount(2)` of a btrfs volume (open_ctree → btrfs_replay_log → __add_inode_ref), so the attacker needs local access to present the crafted image via a block device, loop file, or removable media. There is no network-facing path into btrfs log replay.\nAC:L - Triggering is fully deterministic — the tree-checker's `check_inode_extref()` never validates the embedded `parent_objectid` against the item's hash key, so the attacker simply places a mismatching-parent extref first in the item and sets `super_log_root` so replay runs automatically. No race, timing window, or unpredictable memory layout is involved in reaching the invalid access.\nPR:L - btrfs does not set `FS_USERNS_MOUNT`, but an unprivileged session user routinely causes attacker-supplied btrfs media to be mounted by udisks2/systemd automounters on desktops, kiosks, and shared workstations, and image-processing services loop-mount untrusted images on behalf of low-privileged callers. No elevated capability of the attacker's own is needed in that scenario.\nUI:N - Once the crafted volume is attached, the automounter mounts it and log replay runs unconditionally because `btrfs_super_log_root(disk_super) != 0` is checked with no operator prompt. The attacker performs the mount-triggering action themselves; no separate victim action is required.\nS:U - The out-of-bounds access and the resulting corruption stay within the kernel's own security authority. No hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - The uninitialized `victim_name.len` makes `btrfs_get_64()` read past `eb->len`, and with the accessor's `ASSERT(check_setget_bounds(...))` compiled out on production kernels, `get_eb_folio_index()` runs off the end of `eb->folios[]` (index 16 with an attacker-chosen 64K nodesize on 4K pages), turning adjacent slab contents into a `struct folio *` that `folio_address()` dereferences — an unbounded wild kernel read, not a few-byte bounded one.\nI:H - The out-of-bounds and uninitialized data is interpreted as inode backref metadata and then acted upon: `read_one_inode()` on a garbage `parent_objectid`, `inc_nlink()` on the inode, and `unlink_inode_for_log_replay()` removing directory entries, so kernel memory read out of bounds directly drives modification of filesystem state. Combined with the wild-pointer arithmetic on `eb->folios[]`, this is memory corruption that must be treated as leverageable for control-flow influence.\nA:H - In the common configurations the bogus folio index yields a NULL or wild `folio_address()` dereference during mount, producing a kernel oops, and with `CONFIG_BTRFS_ASSERT=y` the bounds assertion calls `BUG()` outright. Either outcome is a kernel crash in the mount path."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/tree-log.c"],"versions":[{"version":"1cf474cd474bc5d3ef63086ffd009a87a5b7bb2e","lessThan":"539969fc472886a1d63565459514d47e27fef461","status":"affected","versionType":"git"},{"version":"e43eec81c5167b655b72c781b0e75e62a05e415e","lessThan":"2d11d274e2e1d7c79e2ca8461ce3ff3a95c11171","status":"affected","versionType":"git"},{"version":"e43eec81c5167b655b72c781b0e75e62a05e415e","lessThan":"7ac790dc2ba00499a8d671d4a24de4d4ad27e234","status":"affected","versionType":"git"},{"version":"e43eec81c5167b655b72c781b0e75e62a05e415e","lessThan":"aee57a0293dca675637e5504709f9f8fd8e871be","status":"affected","versionType":"git"},{"version":"e43eec81c5167b655b72c781b0e75e62a05e415e","lessThan":"54a7081ed168b72a8a2d6ef4ba3a1259705a2926","status":"affected","versionType":"git"},{"version":"6.1.57","lessThan":"6.1.144","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/tree-log.c"],"versions":[{"version":"6.2","status":"affected"},{"version":"0","lessThan":"6.2","status":"unaffected","versionType":"semver"},{"version":"6.1.144","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.97","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.37","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.15.6","lessThanOrEqual":"6.15.*","status":"unaffected","versionType":"semver"},{"version":"6.16","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.57","versionEndExcluding":"6.1.144"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.12.37"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.15.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.16"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/539969fc472886a1d63565459514d47e27fef461"},{"url":"https://git.kernel.org/stable/c/2d11d274e2e1d7c79e2ca8461ce3ff3a95c11171"},{"url":"https://git.kernel.org/stable/c/7ac790dc2ba00499a8d671d4a24de4d4ad27e234"},{"url":"https://git.kernel.org/stable/c/aee57a0293dca675637e5504709f9f8fd8e871be"},{"url":"https://git.kernel.org/stable/c/54a7081ed168b72a8a2d6ef4ba3a1259705a2926"}],"title":"btrfs: fix iteration of extrefs during log replay","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T17:37:15.284Z"}}]}}