{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38172", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.991Z", "datePublished": "2025-07-03T08:36:10.334Z", "dateUpdated": "2026-08-05T12:00:03.095Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:03.095Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: avoid using multiple devices with different type\n\nFor multiple devices, both primary and extra devices should be the\nsame type. `erofs_init_device` has already guaranteed that if the\nprimary is a file-backed device, extra devices should also be\nregular files.\n\nHowever, if the primary is a block device while the extra device\nis a file-backed device, `erofs_init_device` will get an ENOTBLK,\nwhich is not treated as an error in `erofs_fc_get_tree`, and that\nleads to an UAF:\n\n erofs_fc_get_tree\n get_tree_bdev_flags(erofs_fc_fill_super)\n erofs_read_superblock\n erofs_init_device // sbi->dif0 is not inited yet,\n // return -ENOTBLK\n deactivate_locked_super\n free(sbi)\n if (err is -ENOTBLK)\n sbi->dif0.file = filp_open() // sbi UAF\n\nSo if -ENOTBLK is hitted in `erofs_init_device`, it means the\nprimary device must be a block device, and the extra device\nis not a block device. The error can be converted to -EINVAL." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is reached only through the local mount(2)/fsconfig(2)+fsmount(2) filesystem-mount path on an erofs image plus its `device=` parameters; there is no network-facing consumer of this code.\nAC:L - The trigger is fully deterministic — an erofs image whose on-disk device table count matches the supplied `device=` options, with one such path naming a regular file instead of a block device, reliably yields -ENOTBLK and the use-after-free write on every attempt. Heap reuse of the freed `erofs_sb_info` is attacker-assisted because the free→write window spans an attacker-influenceable `filp_open()` path walk that can be stalled arbitrarily, and the spray runs from the attacker's own threads.\nPR:N - The attacker needs no account or capability on the target: they only supply the malicious erofs image and/or arrange the `device=` path (which is resolved with symlink following at fill_super time, in directories such as container blob/staging dirs) to be a non-block file, while a privileged mounter — automounter, container/composefs runtime, or mount helper handling multi-device erofs images — performs the mount. This matches the kernel CNA treatment of crafted-image mount bugs (e.g. CVE-2025-38204, CVE-2025-38230, CVE-2025-38652).\nUI:R - The flaw only fires when someone mounts the attacker-supplied erofs image with the corresponding `device=` parameters; it cannot be triggered without that mount action.\nS:U - The freed object, the corrupted slab memory, and the resulting crash or escalation are all inside the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `file_inode(sbi->dif0.file)->i_mode` is read back out of the freed `erofs_sb_info`; if a sprayed object has taken the slot the kernel dereferences an attacker-groomed pointer and reads memory at an attacker-chosen location, and use-after-free of a kmalloc object is generally leverageable into kernel-memory disclosure.\nI:H - `sbi->dif0.file = file` writes a valid kernel `struct file *` at a fixed offset (16) into a freed generic-kmalloc chunk, clobbering whatever live object has been reallocated there — a classic UAF write primitive that overwrites pointers/state of an unrelated kernel object and is a strong stepping stone to control-flow hijacking.\nA:H - Even without grooming, the UAF read of poisoned/reused memory and the follow-on `get_tree_nodev()` path (which calls `erofs_fc_fill_super()` with `s_fs_info == NULL`, immediately writing through a NULL `sbi`) produce a kernel oops/panic, and the path also leaks a `struct file` reference on every attempt." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/erofs/super.c" ], "versions": [ { "version": "fb176750266a3d7f42ebdcf28e8ba40350b27847", "lessThan": "65115472f741ca000d7ea4a5922214f93cd1516e", "status": "affected", "versionType": "git" }, { "version": "fb176750266a3d7f42ebdcf28e8ba40350b27847", "lessThan": "cd04beb9ce2773a16057248bb4fa424068ae3807", "status": "affected", "versionType": "git" }, { "version": "fb176750266a3d7f42ebdcf28e8ba40350b27847", "lessThan": "9748f2f54f66743ac77275c34886a9f890e18409", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/erofs/super.c" ], "versions": [ { "version": "6.12", "status": "affected" }, { "version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.34", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.3", "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": "6.12", "versionEndExcluding": "6.12.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.15.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/65115472f741ca000d7ea4a5922214f93cd1516e" }, { "url": "https://git.kernel.org/stable/c/cd04beb9ce2773a16057248bb4fa424068ae3807" }, { "url": "https://git.kernel.org/stable/c/9748f2f54f66743ac77275c34886a9f890e18409" } ], "title": "erofs: avoid using multiple devices with different type", "x_generator": { "engine": "bippy-1.2.0" } } } }