ghsa-hvxw-2j3f-v3hp
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev
Syzkaller reported the following issue:
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:1965:6 index -84 is out of range for type 's8[341]' (aka 'signed char[341]') CPU: 1 PID: 4995 Comm: syz-executor146 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 ubsan_epilogue lib/ubsan.c:217 [inline] __ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348 dbAllocDmapLev+0x3e5/0x430 fs/jfs/jfs_dmap.c:1965 dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1809 dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1350 dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:874 dtSplitUp fs/jfs/jfs_dtree.c:974 [inline] dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:863 jfs_create+0x7b6/0xbb0 fs/jfs/namei.c:137 lookup_open fs/namei.c:3492 [inline] open_last_lookups fs/namei.c:3560 [inline] path_openat+0x13df/0x3170 fs/namei.c:3788 do_filp_open+0x234/0x490 fs/namei.c:3818 do_sys_openat2+0x13f/0x500 fs/open.c:1356 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x247/0x290 fs/open.c:1383 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f1f4e33f7e9 Code: 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 RSP: 002b:00007ffc21129578 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f4e33f7e9 RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c RBP: 00007f1f4e2ff080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f4e2ff110 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
The bug occurs when the dbAllocDmapLev()function attempts to access dp->tree.stree[leafidx + LEAFIND] while the leafidx value is negative.
To rectify this, the patch introduces a safeguard within the dbAllocDmapLev() function. A check has been added to verify if leafidx is negative. If it is, the function immediately returns an I/O error, preventing any further execution that could potentially cause harm.
Tested via syzbot.
{
"affected": [],
"aliases": [
"CVE-2023-53485"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-01T12:15:51Z",
"severity": null
},
"details": "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 \u0027s8[341]\u0027 (aka \u0027signed char[341]\u0027)\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 \u003cTASK\u003e\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 \u003c48\u003e 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 \u003c/TASK\u003e\n\nThe bug occurs when the dbAllocDmapLev()function attempts to access\ndp-\u003etree.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.",
"id": "GHSA-hvxw-2j3f-v3hp",
"modified": "2025-10-01T12:30:30Z",
"published": "2025-10-01T12:30:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-53485"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0d9e678a82915633b99603f744e7735d1a673d72"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/39f6292d75959e8accac0b3e24090094ba0824e9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4e302336d5ca1767a06beee7596a72d3bdc8d983"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/53b0a362aca2583729e8ca2936ca657ff3247d88"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6e7d9d76e5654bcdd3cdb7c9441a8113428ecebb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/911b48eec45152822bccf45cd3563b48256b1520"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bdf07ab1595b613b03f32dbb5cb379edfa1a7334"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f2af019091f904ca08b3572ab0111238ad6d17b3"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
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