ghsa-v6rg-qv6j-p6gp
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
dm cache: fix out-of-bounds access to the dirty bitset when resizing
dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access.
Reproduce steps:
- create a cache device of 1024 cache blocks (128 bytes dirty bitset)
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
- shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80)
dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache
KASAN reports:
BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0 Read of size 8 at addr ffffc900000f3080 by task dmsetup/131
(...snip...) The buggy address belongs to the virtual mapping at [ffffc900000f3000, ffffc900000f5000) created by: cache_ctr+0x176a/0x35f0
(...snip...) Memory state around the buggy address: ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
Fix by making the index post-incremented.
{
"affected": [],
"aliases": [
"CVE-2024-50279"
],
"database_specific": {
"cwe_ids": [
"CWE-125"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-11-19T02:16:30Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm cache: fix out-of-bounds access to the dirty bitset when resizing\n\ndm-cache checks the dirty bits of the cache blocks to be dropped when\nshrinking the fast device, but an index bug in bitset iteration causes\nout-of-bounds access.\n\nReproduce steps:\n\n1. create a cache device of 1024 cache blocks (128 bytes dirty bitset)\n\ndmsetup create cmeta --table \"0 8192 linear /dev/sdc 0\"\ndmsetup create cdata --table \"0 131072 linear /dev/sdc 8192\"\ndmsetup create corig --table \"0 524288 linear /dev/sdc 262144\"\ndd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct\ndmsetup create cache --table \"0 524288 cache /dev/mapper/cmeta \\\n/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0\"\n\n2. shrink the fast device to 512 cache blocks, triggering out-of-bounds\n access to the dirty bitset (offset 0x80)\n\ndmsetup suspend cache\ndmsetup reload cdata --table \"0 65536 linear /dev/sdc 8192\"\ndmsetup resume cdata\ndmsetup resume cache\n\nKASAN reports:\n\n BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0\n Read of size 8 at addr ffffc900000f3080 by task dmsetup/131\n\n (...snip...)\n The buggy address belongs to the virtual mapping at\n [ffffc900000f3000, ffffc900000f5000) created by:\n cache_ctr+0x176a/0x35f0\n\n (...snip...)\n Memory state around the buggy address:\n ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n \u003effffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ^\n ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n\nFix by making the index post-incremented.",
"id": "GHSA-v6rg-qv6j-p6gp",
"modified": "2024-11-27T18:34:01Z",
"published": "2024-11-19T03:31:08Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-50279"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3b02c40ff10fdf83cc545850db208de855ebe22c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4fa4feb873cea0e9d6ff883b37cca6f33169d8b4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/56507203e1b6127967ec2b51fb0b23a0d4af1334"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/792227719725497ce10a8039803bec13f89f8910"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8501e38dc9e0060814c4085815fc83da3e6d43bf"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e57648ce325fa405fe6bbd0e6a618ced7c301a2d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ee1f74925717ab36f6a091104c170639501ce818"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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