linux — security advisory
In the Linux kernel, the following vulnerability has been resolved: zsmalloc: fix races between asynchronous zspage free and page migration The asynchronous zspage free worker tries to lock a zspage's entire page list without defending against page migration. Since pages which haven't yet been locked can concurrently migrate off the zspage page list while lock_zspage() churns away, lock_zspage() can suffer from a few different lethal races. It can lock a page which no longer belongs to the zspage and unsafely dereference page_private(), it can unsafely dereference a torn pointer to the next page (since there's a data race), and it can observe a spurious NULL pointer to the next page and thus not lock all of the zspage's pages (since a single page migration will reconstruct the entire page list, and create_page_chain() unconditionally zeroes out each list pointer in the process). Fix the races by using migrate_read_lock() in lock_zspage() to synchronize with page migration.
- Products
- linux
- Affected versions
- Not specified
- Fixed versions
- 5.18.2-1
- CVEs
- CVE-2022-49554
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 19:58 UTC · Revision 1
Source evidence
In the Linux kernel, the following vulnerability has been resolved: zsmalloc: fix races between asynchronous zspage free and page migration The asynchronous zspage free worker tries to lock a zspage's entire page list without defending against page migration. Since pages which haven't yet been locked can concurrently migrate off the zspage page list while lock_zspage() churns away, lock_zspage() can suffer from a few different lethal races. It can lock a page which no longer belongs to the zspage and unsafely dereference page_private(), it can unsafely dereference a torn pointer to the next page (since there's a data race), and it can observe a spurious NULL pointer to the next page and thus not lock all of the zspage's pages (since a single page migration will reconstruct the entire page list, and create_page_chain() unconditionally zeroes out each list pointer in the process). Fix the races by using migrate_read_lock() in lock_zspage() to synchronize with page migration.
osv:DEBIAN-CVE-2022-49554
linux
Fixed versions: 5.18.2-1
linux
Fixed versions: 5.18.2-1
linux
Fixed versions: 5.18.2-1
Complete source record
{
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"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2022-49554",
"method": "structured",
"payload": {
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"title": "DEBIAN-CVE-2022-49554",
"summary": "In the Linux kernel, the following vulnerability has been resolved: zsmalloc: fix races between asynchronous zspage free and page migration The asynchronous zspage free worker tries to lock a zspage's entire page list without defending against page migration. Since pages which haven't yet been locked can concurrently migrate off the zspage page list while lock_zspage() churns away, lock_zspage() can suffer from a few different lethal races. It can lock a page which no longer belongs to the zspage and unsafely dereference page_private(), it can unsafely dereference a torn pointer to the next page (since there's a data race), and it can observe a spurious NULL pointer to the next page and thus not lock all of the zspage's pages (since a single page migration will reconstruct the entire page list, and create_page_chain() unconditionally zeroes out each list pointer in the process). Fix the races by using migrate_read_lock() in lock_zspage() to synchronize with page migration.",
"evidence": "osv:DEBIAN-CVE-2022-49554",
"products": [
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"package": {
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],
"modified": "2026-10-16T09:47:29.250074164Z",
"provider": "osv",
"upstream": [
"CVE-2022-49554"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2022-49554"
]
},
"related_cves": [
{
"value": "CVE-2022-49554",
"evidence": "/upstream"
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],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 338605,
"published_at": "2025-02-26T07:01:31.223+00:00"
}