ghsa-xgm7-3x53-gq2c
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: batman-adv: fix error handling
Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init().
Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any.
All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1]
To fix these bugs we can unwind batadv_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_free() functions.
So, this patch makes all batadv_init() clean up all allocated memory before returning with an error to no call correspoing batadv_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.
{
"affected": [],
"aliases": [
"CVE-2021-47482"
],
"database_specific": {
"cwe_ids": [
"CWE-544"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-22T09:15:10Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: batman-adv: fix error handling\n\nSyzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was\nin wrong error handling in batadv_mesh_init().\n\nBefore this patch batadv_mesh_init() was calling batadv_mesh_free() in case\nof any batadv_*_init() calls failure. This approach may work well, when\nthere is some kind of indicator, which can tell which parts of batadv are\ninitialized; but there isn\u0027t any.\n\nAll written above lead to cleaning up uninitialized fields. Even if we hide\nODEBUG warning by initializing bat_priv-\u003enc.work, syzbot was able to hit\nGPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1]\n\nTo fix these bugs we can unwind batadv_*_init() calls one by one.\nIt is good approach for 2 reasons: 1) It fixes bugs on error handling\npath 2) It improves the performance, since we won\u0027t call unneeded\nbatadv_*_free() functions.\n\nSo, this patch makes all batadv_*_init() clean up all allocated memory\nbefore returning with an error to no call correspoing batadv_*_free()\nand open-codes batadv_mesh_free() with proper order to avoid touching\nuninitialized fields.",
"id": "GHSA-xgm7-3x53-gq2c",
"modified": "2024-07-03T18:43:07Z",
"published": "2024-05-22T09:31:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-47482"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/07533f1a673ce1126d0a72ef1e4b5eaaa3dd6d20"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0c6b199f09be489c48622537a550787fc80aea73"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6422e8471890273994fe8cc6d452b0dcd2c9483e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6f68cd634856f8ca93bafd623ba5357e0f648c68"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a8f7359259dd5923adc6129284fdad12fc5db347"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b0a2cd38553c77928ef1646ed1518486b1e70ae8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e50f957652190b5a88a8ebce7e5ab14ebd0d3f00"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fbf150b16a3635634b7dfb7f229d8fcd643c6c51"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}