{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40349", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.187Z", "datePublished": "2025-12-16T13:30:23.092Z", "dateUpdated": "2026-08-05T12:09:49.208Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:09:49.208Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhfs: validate record offset in hfsplus_bmap_alloc\n\nhfsplus_bmap_alloc can trigger a crash if a\nrecord offset or length is larger than node_size\n\n[ 15.264282] BUG: KASAN: slab-out-of-bounds in hfsplus_bmap_alloc+0x887/0x8b0\n[ 15.265192] Read of size 8 at addr ffff8881085ca188 by task test/183\n[ 15.265949]\n[ 15.266163] CPU: 0 UID: 0 PID: 183 Comm: test Not tainted 6.17.0-rc2-gc17b750b3ad9 #14 PREEMPT(voluntary)\n[ 15.266165] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[ 15.266167] Call Trace:\n[ 15.266168] \n[ 15.266169] dump_stack_lvl+0x53/0x70\n[ 15.266173] print_report+0xd0/0x660\n[ 15.266181] kasan_report+0xce/0x100\n[ 15.266185] hfsplus_bmap_alloc+0x887/0x8b0\n[ 15.266208] hfs_btree_inc_height.isra.0+0xd5/0x7c0\n[ 15.266217] hfsplus_brec_insert+0x870/0xb00\n[ 15.266222] __hfsplus_ext_write_extent+0x428/0x570\n[ 15.266225] __hfsplus_ext_cache_extent+0x5e/0x910\n[ 15.266227] hfsplus_ext_read_extent+0x1b2/0x200\n[ 15.266233] hfsplus_file_extend+0x5a7/0x1000\n[ 15.266237] hfsplus_get_block+0x12b/0x8c0\n[ 15.266238] __block_write_begin_int+0x36b/0x12c0\n[ 15.266251] block_write_begin+0x77/0x110\n[ 15.266252] cont_write_begin+0x428/0x720\n[ 15.266259] hfsplus_write_begin+0x51/0x100\n[ 15.266262] cont_write_begin+0x272/0x720\n[ 15.266270] hfsplus_write_begin+0x51/0x100\n[ 15.266274] generic_perform_write+0x321/0x750\n[ 15.266285] generic_file_write_iter+0xc3/0x310\n[ 15.266289] __kernel_write_iter+0x2fd/0x800\n[ 15.266296] dump_user_range+0x2ea/0x910\n[ 15.266301] elf_core_dump+0x2a94/0x2ed0\n[ 15.266320] vfs_coredump+0x1d85/0x45e0\n[ 15.266349] get_signal+0x12e3/0x1990\n[ 15.266357] arch_do_signal_or_restart+0x89/0x580\n[ 15.266362] irqentry_exit_to_user_mode+0xab/0x110\n[ 15.266364] asm_exc_page_fault+0x26/0x30\n[ 15.266366] RIP: 0033:0x41bd35\n[ 15.266367] Code: bc d1 f3 0f 7f 27 f3 0f 7f 6f 10 f3 0f 7f 77 20 f3 0f 7f 7f 30 49 83 c0 0f 49 29 d0 48 8d 7c 17 31 e9 9f 0b 00 00 66 0f ef c0 0f 6f 0e f3 0f 6f 56 10 66 0f 74 c1 66 0f d7 d0 49 83 f8f\n[ 15.266369] RSP: 002b:00007ffc9e62d078 EFLAGS: 00010283\n[ 15.266371] RAX: 00007ffc9e62d100 RBX: 0000000000000000 RCX: 0000000000000000\n[ 15.266372] RDX: 00000000000000e0 RSI: 0000000000000000 RDI: 00007ffc9e62d100\n[ 15.266373] RBP: 0000400000000040 R08: 00000000000000e0 R09: 0000000000000000\n[ 15.266374] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\n[ 15.266375] R13: 0000000000000000 R14: 0000000000000000 R15: 0000400000000000\n[ 15.266376] \n\nWhen calling hfsplus_bmap_alloc to allocate a free node, this function\nfirst retrieves the bitmap from header node and map node using node->page\ntogether with the offset and length from hfs_brec_lenoff\n\n```\nlen = hfs_brec_lenoff(node, 2, &off16);\noff = off16;\n\noff += node->page_offset;\npagep = node->page + (off >> PAGE_SHIFT);\ndata = kmap_local_page(*pagep);\n```\n\nHowever, if the retrieved offset or length is invalid(i.e. exceeds\nnode_size), the code may end up accessing pages outside the allocated\nrange for this node.\n\nThis patch adds proper validation of both offset and length before use,\npreventing out-of-bounds page access. Move is_bnode_offset_valid and\ncheck_and_correct_requested_length to hfsplus_fs.h, as they may be\nrequired by other functions." } ], "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 vulnerability is reached by mounting a crafted HFS+ volume and then performing an ordinary local file operation (write/create) on it; there is no network-facing component. Local mounting of attacker-supplied images is available via udisks2/loop-setup for active local sessions, fstab `user` entries, and desktop/kiosk automount.\nAC:L - The out-of-bounds offset and length are read verbatim from attacker-authored on-disk metadata, so the OOB access is fully deterministic — no race, timing, or uncontrolled memory-layout condition is involved.\nPR:L - After the crafted volume is mounted, an unprivileged local user with write access to it reaches hfs_bmap_alloc through a plain write() that extends a file — no capability check exists anywhere on the hfsplus_file_extend → hfsplus_brec_insert → hfs_btree_inc_height path.\nUI:N - In the removable-media/automount and udisks2 scenarios the volume is mounted without any deliberate victim action, and the trigger itself is a normal file write performed by the attacker.\nS:U - The corruption is confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The code performs a slab out-of-bounds read of an 8-byte value past node->page[], then dereferences that value as a struct page and reads bytes through the resulting mapping, yielding attacker-influenced disclosure of arbitrary kernel memory.\nI:H - The loop performs `data[off] |= m` and set_page_dirty() through the bogus, heap-groomable page pointer, giving an out-of-bounds bit-set write into kernel memory that is exploitable for control-flow hijacking or privilege escalation.\nA:H - Dereferencing a garbage struct page pointer and writing through it reliably produces a KASAN report, oops, or kernel panic, crashing the system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/hfsplus/bnode.c", "fs/hfsplus/btree.c", "fs/hfsplus/hfsplus_fs.h" ], "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "f7d9f600c7c3ff5dab36181a388af55f2c95604c", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "40dfe7a4215a1f20842561ffaf5a6f83a987e75b", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "418e48cab99c52c1760636a4dbe464bf6db2018b", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "0058d20d76182861dbdd8fd6e2dd8d18d6d3becf", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "4f40a2b3969daf10dca4dea6f6dd0e813f79b227", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "17ed51cfce6c62cffb97059ef392ad2e0245806e", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "068a46df3e6acc68fb9db0a6313ab379a11ecd6f", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "738d5a51864ed8d7a68600b8c0c63fe6fe5c4f20", "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/hfsplus/bnode.c", "fs/hfsplus/btree.c", "fs/hfsplus/hfsplus_fs.h" ], "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": "5.15.196", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.158", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.115", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.56", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.6", "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": "5.15.196" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.1.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.6.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.56" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.17.6" }, { "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/f7d9f600c7c3ff5dab36181a388af55f2c95604c" }, { "url": "https://git.kernel.org/stable/c/40dfe7a4215a1f20842561ffaf5a6f83a987e75b" }, { "url": "https://git.kernel.org/stable/c/418e48cab99c52c1760636a4dbe464bf6db2018b" }, { "url": "https://git.kernel.org/stable/c/0058d20d76182861dbdd8fd6e2dd8d18d6d3becf" }, { "url": "https://git.kernel.org/stable/c/4f40a2b3969daf10dca4dea6f6dd0e813f79b227" }, { "url": "https://git.kernel.org/stable/c/17ed51cfce6c62cffb97059ef392ad2e0245806e" }, { "url": "https://git.kernel.org/stable/c/068a46df3e6acc68fb9db0a6313ab379a11ecd6f" }, { "url": "https://git.kernel.org/stable/c/738d5a51864ed8d7a68600b8c0c63fe6fe5c4f20" } ], "title": "hfs: validate record offset in hfsplus_bmap_alloc", "x_generator": { "engine": "bippy-1.2.0" } } } }