ghsa-q844-wpfg-w2h9
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
libfs: fix infinite directory reads for offset dir
After we switch tmpfs dir operations from simple_dir_operations to simple_offset_dir_operations, every rename happened will fill new dentry to dest dir's maple tree(&SHMEM_I(inode)->dir_offsets->mt) with a free key starting with octx->newx_offset, and then set newx_offset equals to free key + 1. This will lead to infinite readdir combine with rename happened at the same time, which fail generic/736 in xfstests(detail show as below).
- create 5000 files(1 2 3...) under one dir
- call readdir(man 3 readdir) once, and get one entry
- rename(entry, "TEMPFILE"), then rename("TEMPFILE", entry)
- loop 2~3, until readdir return nothing or we loop too many times(tmpfs break test with the second condition)
We choose the same logic what commit 9b378f6ad48cf ("btrfs: fix infinite directory reads") to fix it, record the last_index when we open dir, and do not emit the entry which index >= last_index. The file->private_data now used in offset dir can use directly to do this, and we also update the last_index when we llseek the dir file.
[brauner: only update last_index after seek when offset is zero like Jan suggested]
{
"affected": [],
"aliases": [
"CVE-2024-46701"
],
"database_specific": {
"cwe_ids": [
"CWE-835"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-13T07:15:05Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibfs: fix infinite directory reads for offset dir\n\nAfter we switch tmpfs dir operations from simple_dir_operations to\nsimple_offset_dir_operations, every rename happened will fill new dentry\nto dest dir\u0027s maple tree(\u0026SHMEM_I(inode)-\u003edir_offsets-\u003emt) with a free\nkey starting with octx-\u003enewx_offset, and then set newx_offset equals to\nfree key + 1. This will lead to infinite readdir combine with rename\nhappened at the same time, which fail generic/736 in xfstests(detail show\nas below).\n\n1. create 5000 files(1 2 3...) under one dir\n2. call readdir(man 3 readdir) once, and get one entry\n3. rename(entry, \"TEMPFILE\"), then rename(\"TEMPFILE\", entry)\n4. loop 2~3, until readdir return nothing or we loop too many\n times(tmpfs break test with the second condition)\n\nWe choose the same logic what commit 9b378f6ad48cf (\"btrfs: fix infinite\ndirectory reads\") to fix it, record the last_index when we open dir, and\ndo not emit the entry which index \u003e= last_index. The file-\u003eprivate_data\nnow used in offset dir can use directly to do this, and we also update\nthe last_index when we llseek the dir file.\n\n[brauner: only update last_index after seek when offset is zero like Jan suggested]",
"id": "GHSA-q844-wpfg-w2h9",
"modified": "2024-09-19T15:30:49Z",
"published": "2024-09-13T09:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-46701"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/308b4fc2403b335894592ee9dc212a5e58bb309f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/64a7ce76fb901bf9f9c36cf5d681328fc0fd4b5a"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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