{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40044", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.154Z", "datePublished": "2025-10-28T11:48:22.827Z", "dateUpdated": "2026-08-05T12:07:17.312Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:07:17.312Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs: udf: fix OOB read in lengthAllocDescs handling\n\nWhen parsing Allocation Extent Descriptor, lengthAllocDescs comes from\non-disk data and must be validated against the block size. Crafted or\ncorrupted images may set lengthAllocDescs so that the total descriptor\nlength (sizeof(allocExtDesc) + lengthAllocDescs) exceeds the buffer,\nleading udf_update_tag() to call crc_itu_t() on out-of-bounds memory and\ntrigger a KASAN use-after-free read.\n\nBUG: KASAN: use-after-free in crc_itu_t+0x1d5/0x2b0 lib/crc-itu-t.c:60\nRead of size 1 at addr ffff888041e7d000 by task syz-executor317/5309\n\nCPU: 0 UID: 0 PID: 5309 Comm: syz-executor317 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\nCall Trace:\n \n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n crc_itu_t+0x1d5/0x2b0 lib/crc-itu-t.c:60\n udf_update_tag+0x70/0x6a0 fs/udf/misc.c:261\n udf_write_aext+0x4d8/0x7b0 fs/udf/inode.c:2179\n extent_trunc+0x2f7/0x4a0 fs/udf/truncate.c:46\n udf_truncate_tail_extent+0x527/0x7e0 fs/udf/truncate.c:106\n udf_release_file+0xc1/0x120 fs/udf/file.c:185\n __fput+0x23f/0x880 fs/file_table.c:431\n task_work_run+0x24f/0x310 kernel/task_work.c:239\n exit_task_work include/linux/task_work.h:43 [inline]\n do_exit+0xa2f/0x28e0 kernel/exit.c:939\n do_group_exit+0x207/0x2c0 kernel/exit.c:1088\n __do_sys_exit_group kernel/exit.c:1099 [inline]\n __se_sys_exit_group kernel/exit.c:1097 [inline]\n __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097\n x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n \n\nValidate the computed total length against epos->bh->b_size.\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller." } ], "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 triggered by parsing a crafted UDF filesystem image presented as local storage (removable media or a loop-mounted file); all trigger paths are local syscalls (mount/statfs, readdir, read, close, unlink) on the mounted volume. No network protocol handling is involved.\nAC:L - The attacker fully controls the on-disk `lengthAllocDescs` field and simply sets it larger than the block size, which deterministically drives `alen` past the buffer with no race, timing, or memory-layout condition outside their control.\nPR:N - The attacker needs no account or privileges on the target system — they only author the malicious UDF image/media (the DVD/Blu-ray/USB-stick format), and the mount is performed by an automounter or the victim; after mount, every trigger path is available to any unprivileged reader of the volume.\nUI:R - Exploitation requires the crafted image to be mounted, i.e. a victim inserting the media or mounting the image (udisks2/desktop automount counts as the required action), followed by ordinary access such as `ls` or opening and closing a file.\nS:U - The out-of-bounds read and write stay within the kernel's own heap and the kernel's security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `udf_get_fileshortad()`/`udf_get_filelongad()` are bounded only by the bogus `alen`, allowing reads of kernel heap up to ~4 GiB past the buffer (confirmed KASAN use-after-free read), and the values harvested from freed/adjacent memory are used as block locations and extent lengths that steer subsequent I/O and directory results.\nI:H - `udf_write_aext()` writes an 8- or 16-byte extent descriptor at `bh->b_data + epos->offset` with the offset unbounded and the contents attacker-influenced, giving a heap out-of-bounds write suitable for control-structure corruption; `extent_trunc()` additionally frees blocks named by out-of-bounds-read data, corrupting on-disk allocation bitmaps.\nA:H - The reported syzbot reproducer produces a KASAN use-after-free read in `crc_itu_t()`, and the unbounded ~4 GiB CRC scan past the buffer reliably faults into unmapped memory, causing a kernel oops/panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/udf/inode.c" ], "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "14496175b264d30c2045584ee31d062af2e3a660", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "d2ed9aa8ae50fb0d4ac5ab07e4c67ba7e9a24818", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "1d1847812a1a5375c10a2a779338df643f79c047", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "918649364fbca7d5df72522ca795479edcd25f91", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "a70dcfa8d0a0cc530a6af59483dfca260b652c1b", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "b57f2d7d3e6bb89ed82330c5fe106cdfa34d3e24", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "459404f858213967ccfff336c41747d8dd186d38", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "3bd5e45c2ce30e239d596becd5db720f7eb83c99", "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/udf/inode.c" ], "versions": [ { "version": "2.6.12", "status": "affected" }, { "version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.301", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.246", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.195", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.156", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.112", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.53", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.3", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "2.6.12", "versionEndExcluding": "5.4.301" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.10.246" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.15.195" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.1.156" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.6.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.17.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/14496175b264d30c2045584ee31d062af2e3a660" }, { "url": "https://git.kernel.org/stable/c/d2ed9aa8ae50fb0d4ac5ab07e4c67ba7e9a24818" }, { "url": "https://git.kernel.org/stable/c/1d1847812a1a5375c10a2a779338df643f79c047" }, { "url": "https://git.kernel.org/stable/c/918649364fbca7d5df72522ca795479edcd25f91" }, { "url": "https://git.kernel.org/stable/c/a70dcfa8d0a0cc530a6af59483dfca260b652c1b" }, { "url": "https://git.kernel.org/stable/c/b57f2d7d3e6bb89ed82330c5fe106cdfa34d3e24" }, { "url": "https://git.kernel.org/stable/c/459404f858213967ccfff336c41747d8dd186d38" }, { "url": "https://git.kernel.org/stable/c/3bd5e45c2ce30e239d596becd5db720f7eb83c99" } ], "title": "fs: udf: fix OOB read in lengthAllocDescs handling", "x_generator": { "engine": "bippy-1.2.0" } } } }