{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53485", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-01T11:39:39.402Z", "datePublished": "2025-10-01T11:42:53.337Z", "dateUpdated": "2026-08-05T09:14:20.042Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:14:20.042Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev\n\nSyzkaller reported the following issue:\n\nUBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:1965:6\nindex -84 is out of range for type 's8[341]' (aka 'signed char[341]')\nCPU: 1 PID: 4995 Comm: syz-executor146 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023\nCall Trace:\n \n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106\n ubsan_epilogue lib/ubsan.c:217 [inline]\n __ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348\n dbAllocDmapLev+0x3e5/0x430 fs/jfs/jfs_dmap.c:1965\n dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1809\n dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1350\n dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:874\n dtSplitUp fs/jfs/jfs_dtree.c:974 [inline]\n dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:863\n jfs_create+0x7b6/0xbb0 fs/jfs/namei.c:137\n lookup_open fs/namei.c:3492 [inline]\n open_last_lookups fs/namei.c:3560 [inline]\n path_openat+0x13df/0x3170 fs/namei.c:3788\n do_filp_open+0x234/0x490 fs/namei.c:3818\n do_sys_openat2+0x13f/0x500 fs/open.c:1356\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_openat fs/open.c:1388 [inline]\n __se_sys_openat fs/open.c:1383 [inline]\n __x64_sys_openat+0x247/0x290 fs/open.c:1383\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\nRIP: 0033:0x7f1f4e33f7e9\nCode: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007ffc21129578 EFLAGS: 00000246 ORIG_RAX: 0000000000000101\nRAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f4e33f7e9\nRDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c\nRBP: 00007f1f4e2ff080 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f4e2ff110\nR13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\n \n\nThe bug occurs when the dbAllocDmapLev()function attempts to access\ndp->tree.stree[leafidx + LEAFIND] while the leafidx value is negative.\n\nTo rectify this, the patch introduces a safeguard within the\ndbAllocDmapLev() function. A check has been added to verify if leafidx is\nnegative. If it is, the function immediately returns an I/O error, preventing\nany further execution that could potentially cause harm.\n\nTested via syzbot." } ], "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 through local syscalls (`openat(O_CREAT)` on a mounted JFS volume) after a crafted JFS image is attached; there is no network-facing consumer of this code.\nAC:L - The attacker fully controls the on-disk `dmt_leafidx`/`start` fields of the dmap page, so the negative index and the resulting bogus block number are produced deterministically on the first file creation — no race or unpredictable state is involved.\nPR:L - An unprivileged local user suffices in realistic deployments — udisks2/autofs on desktops, kiosks and shared workstations loop-mount or auto-mount user-supplied JFS media without root, after which any write to the mounted directory reaches `dbAlloc()`.\nUI:N - The attacker performs every step themselves (supply the image, have it auto/loop-mounted, create a file); no action by a separate victim user is required.\nS:U - The corruption stays within the kernel's own security authority — standard in-kernel memory and filesystem-metadata corruption with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - `stree[leafidx + LEAFIND]` and `dp->wmap[leafidx]` are read at an unvalidated, attacker-chosen negative offset (`dmt_leafidx` is a full `__le32`), giving an unbounded out-of-bounds read of kernel memory whose contents steer the subsequent block-allocation result and are thus observable.\nI:H - The bogus `blkno` propagates into `dbAllocBits()`, where `bmp->db_agfree[agno] -= nblocks` writes at an attacker-influenced out-of-range index of the kmalloc'd `struct bmap`, and into `dbSplit()`/`dbAdjTree()`, which write past the metapage using the same unvalidated `dmt_leafidx` — heap out-of-bounds writes usable for control-flow corruption.\nA:H - A far-negative index dereferences unmapped memory and the corrupted allocation state feeds `jfs_error()`/inconsistent block accounting, producing a kernel oops or panic that the attacker can trigger at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/jfs/jfs_dmap.c" ], "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "0d9e678a82915633b99603f744e7735d1a673d72", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "53b0a362aca2583729e8ca2936ca657ff3247d88", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "6e7d9d76e5654bcdd3cdb7c9441a8113428ecebb", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "911b48eec45152822bccf45cd3563b48256b1520", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "39f6292d75959e8accac0b3e24090094ba0824e9", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "bdf07ab1595b613b03f32dbb5cb379edfa1a7334", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "f2af019091f904ca08b3572ab0111238ad6d17b3", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "4e302336d5ca1767a06beee7596a72d3bdc8d983", "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/jfs/jfs_dmap.c" ], "versions": [ { "version": "2.6.12", "status": "affected" }, { "version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.324", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.293", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.255", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.192", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.123", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.42", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.7", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5", "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": "4.14.324" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "4.19.293" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.4.255" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.10.192" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.15.123" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.1.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.4.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.5" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0d9e678a82915633b99603f744e7735d1a673d72" }, { "url": "https://git.kernel.org/stable/c/53b0a362aca2583729e8ca2936ca657ff3247d88" }, { "url": "https://git.kernel.org/stable/c/6e7d9d76e5654bcdd3cdb7c9441a8113428ecebb" }, { "url": "https://git.kernel.org/stable/c/911b48eec45152822bccf45cd3563b48256b1520" }, { "url": "https://git.kernel.org/stable/c/39f6292d75959e8accac0b3e24090094ba0824e9" }, { "url": "https://git.kernel.org/stable/c/bdf07ab1595b613b03f32dbb5cb379edfa1a7334" }, { "url": "https://git.kernel.org/stable/c/f2af019091f904ca08b3572ab0111238ad6d17b3" }, { "url": "https://git.kernel.org/stable/c/4e302336d5ca1767a06beee7596a72d3bdc8d983" } ], "title": "fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev", "x_generator": { "engine": "bippy-1.2.0" } } } }