ghsa-8v7x-4vvg-pgr3
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
cxl/region: Do not try to cleanup after cxl_region_setup_targets() fails
Commit 5e42bcbc3fef ("cxl/region: decrement ->nr_targets on error in cxl_region_attach()") tried to avoid 'eiw' initialization errors when ->nr_targets exceeded 16, by just decrementing ->nr_targets when cxl_region_setup_targets() failed.
Commit 86987c766276 ("cxl/region: Cleanup target list on attach error") extended that cleanup to also clear cxled->pos and p->targets[pos]. The initialization error was incidentally fixed separately by: Commit 8d4285425714 ("cxl/region: Fix port setup uninitialized variable warnings") which was merged a few days after 5e42bcbc3fef.
But now the original cleanup when cxl_region_setup_targets() fails prevents endpoint and switch decoder resources from being reused:
1) the cleanup does not set the decoder's region to NULL, which results in future dpa_size_store() calls returning -EBUSY 2) the decoder is not properly freed, which results in future commit errors associated with the upstream switch
Now that the initialization errors were fixed separately, the proper cleanup for this case is to just return immediately. Then the resources associated with this target get cleanup up as normal when the failed region is deleted.
The ->nr_targets decrement in the error case also helped prevent a p->targets[] array overflow, so add a new check to prevent against that overflow.
Tested by trying to create an invalid region for a 2 switch * 2 endpoint topology, and then following up with creating a valid region.
{
"affected": [],
"aliases": [
"CVE-2023-52792"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-21T16:15:17Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/region: Do not try to cleanup after cxl_region_setup_targets() fails\n\nCommit 5e42bcbc3fef (\"cxl/region: decrement -\u003enr_targets on error in\ncxl_region_attach()\") tried to avoid \u0027eiw\u0027 initialization errors when\n-\u003enr_targets exceeded 16, by just decrementing -\u003enr_targets when\ncxl_region_setup_targets() failed.\n\nCommit 86987c766276 (\"cxl/region: Cleanup target list on attach error\")\nextended that cleanup to also clear cxled-\u003epos and p-\u003etargets[pos]. The\ninitialization error was incidentally fixed separately by:\nCommit 8d4285425714 (\"cxl/region: Fix port setup uninitialized variable\nwarnings\") which was merged a few days after 5e42bcbc3fef.\n\nBut now the original cleanup when cxl_region_setup_targets() fails\nprevents endpoint and switch decoder resources from being reused:\n\n1) the cleanup does not set the decoder\u0027s region to NULL, which results\n in future dpa_size_store() calls returning -EBUSY\n2) the decoder is not properly freed, which results in future commit\n errors associated with the upstream switch\n\nNow that the initialization errors were fixed separately, the proper\ncleanup for this case is to just return immediately. Then the resources\nassociated with this target get cleanup up as normal when the failed\nregion is deleted.\n\nThe -\u003enr_targets decrement in the error case also helped prevent\na p-\u003etargets[] array overflow, so add a new check to prevent against\nthat overflow.\n\nTested by trying to create an invalid region for a 2 switch * 2 endpoint\ntopology, and then following up with creating a valid region.",
"id": "GHSA-8v7x-4vvg-pgr3",
"modified": "2024-05-21T18:31:21Z",
"published": "2024-05-21T18:31:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-52792"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0718588c7aaa7a1510b4de972370535b61dddd0d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/07ffcd8ec79cf7383e1e45815f4842fd357991c2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9090c5537c93cd0811ab7bfbd925b57addfffb60"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/90db4c1d5ebaf574d3c3065c055977982c378a83"
}
],
"schema_version": "1.4.0",
"severity": []
}
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- Patched: This vulnerability was successfully patched by the user reporting the sighting.
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