f2fs: avoid NULL checkpoint thread access in sysfs
In the Linux kernel, the following vulnerability has been resolved: f2fs: avoid NULL checkpoint thread access in sysfs checkpoint_merge can be enabled even when no checkpoint merge thread is running. A read-only mount is one case: f2fs does not start f2fs_issue_ckpt there, but ckpt_thread_ioprio is still writable through sysfs. The ckpt_thread_ioprio store path updates the saved ioprio value and, when checkpoint_merge is enabled, calls set_task_ioprio() for the checkpoint thread. If cprc->f2fs_issue_ckpt is NULL, that dereferences a NULL task pointer. Protect ckpt_thread_ioprio sysfs writes with s_umount as well, so the checkpoint thread cannot disappear under the store path while updating its ioprio.
CVE-2026-89835
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-2026-89835
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": "e65920661708b7c0f3db45c9cd5d0095034ee37f",
"lessThan": "22760e3e9cecbddc475edc91600787abf407a302",
"versionType": "git"
},
{
"status": "affected",
"version": "e65920661708b7c0f3db45c9cd5d0095034ee37f",
"lessThan": "a6573f3ffc19542de9ebc1a2b1f930fd48ba538c",
"versionType": "git"
},
{
"status": "affected",
"version": "e65920661708b7c0f3db45c9cd5d0095034ee37f",
"lessThan": "aefcec3bebdeed2bff444378122300763325ba23",
"versionType": "git"
},
{
"status": "affected",
"version": "e65920661708b7c0f3db45c9cd5d0095034ee37f",
"lessThan": "8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b",
"versionType": "git"
},
{
"status": "affected",
"version": "e65920661708b7c0f3db45c9cd5d0095034ee37f",
"lessThan": "5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f",
"versionType": "git"
}
],
"programFiles": [
"fs/f2fs/sysfs.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/f2fs/sysfs.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89835
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48557 · Revision 1
- Added to Heist Feed
- Publisher date