ghsa-hf2g-j6wm-qrrx
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()
Syzbot reports a warning as follows:
============================================
WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290
Modules linked in:
CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7
RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419
Call Trace:
This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage.
So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.
{
"affected": [],
"aliases": [
"CVE-2024-39276"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-25T15:15:13Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix mb_cache_entry\u0027s e_refcnt leak in ext4_xattr_block_cache_find()\n\nSyzbot reports a warning as follows:\n\n============================================\nWARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290\nModules linked in:\nCPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7\nRIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419\nCall Trace:\n \u003cTASK\u003e\n ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375\n generic_shutdown_super+0x136/0x2d0 fs/super.c:641\n kill_block_super+0x44/0x90 fs/super.c:1675\n ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327\n[...]\n============================================\n\nThis is because when finding an entry in ext4_xattr_block_cache_find(), if\next4_sb_bread() returns -ENOMEM, the ce\u0027s e_refcnt, which has already grown\nin the __entry_find(), won\u0027t be put away, and eventually trigger the above\nissue in mb_cache_destroy() due to reference count leakage.\n\nSo call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.",
"id": "GHSA-hf2g-j6wm-qrrx",
"modified": "2024-11-05T18:31:59Z",
"published": "2024-06-25T15:31:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-39276"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0c0b4a49d3e7f49690a6827a41faeffad5df7e21"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/681ff9a09accd8a4379f8bd30b7a1641ee19bb3e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/76dc776153a47372719d664e0fc50d6355791abb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/896a7e7d0d555ad8b2b46af0c2fa7de7467f9483"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9ad75e78747b5a50dc5a52f0f8e92e920a653f16"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a95df6f04f2c37291adf26a74205cde0314d4577"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b37c0edef4e66fb21a2fbc211471195a383e5ab8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e941b712e758f615d311946bf98216e79145ccd9"
}
],
"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:N",
"type": "CVSS_V3"
}
]
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.