btrfs: zstd: fix lost wakeup when waiting for a workspace
In the Linux kernel, the following vulnerability has been resolved: btrfs: zstd: fix lost wakeup when waiting for a workspace A writer can sleep forever in zstd_get_workspace() even though a workspace is free. When zstd_alloc_workspace() fails, the task is queued on zwsm->wait and schedules unconditionally, never re-testing the pool. zstd_put_workspace() publishes the workspace and then calls cond_wake_up(), which only wakes when a sleeper is already visible, so a workspace returned between the failed allocation and prepare_to_wait() wakes nobody. The window is wide: zstd_alloc_workspace() goes through kvmalloc() and may enter reclaim. Only a max level workspace triggers the wakeup and one is deliberately kept allocated as the fallback every waiter waits for, so once its wakeup is lost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens to return one. Re-check the pool after prepare_to_wait() has published the waiter, and use the workspace if one turned up.
CVE-2026-98079
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98079
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3f93aef535c8ea03e40cd8acf0753b3e6ed33e96",
"lessThan": "14d982762945d9945c60bbd48b77df194dd8e28d",
"versionType": "git"
},
{
"status": "affected",
"version": "3f93aef535c8ea03e40cd8acf0753b3e6ed33e96",
"lessThan": "844603cf842ee67640d33f350e3fa60f3de7fad3",
"versionType": "git"
},
{
"status": "affected",
"version": "3f93aef535c8ea03e40cd8acf0753b3e6ed33e96",
"lessThan": "d8f57049521948df5f50797141472fbbed3b0723",
"versionType": "git"
},
{
"status": "affected",
"version": "3f93aef535c8ea03e40cd8acf0753b3e6ed33e96",
"lessThan": "0de9f31d447ae71ab08c7850a321682f8d2907c3",
"versionType": "git"
},
{
"status": "affected",
"version": "3f93aef535c8ea03e40cd8acf0753b3e6ed33e96",
"lessThan": "2acb9f3d1cc8f65dc81ed55e238cbf8e5b60bff7",
"versionType": "git"
}
],
"programFiles": [
"fs/btrfs/zstd.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/btrfs/zstd.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98079
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48846 · Revision 1
- Added to Heist Feed
- Publisher date