sched/psi: use kernfs polling functions for PSI trigger polling
In the Linux kernel, the following vulnerability has been resolved: sched/psi: use kernfs polling functions for PSI trigger polling Destroying psi trigger in cgroup_file_release causes UAF issues when a cgroup is removed from under a polling process. This is happening because cgroup removal causes a call to cgroup_file_release while the actual file is still alive. Destroying the trigger at this point would also destroy its waitqueue head and if there is still a polling process on that file accessing the waitqueue, it will step on the freed pointer: do_select vfs_poll do_rmdir cgroup_rmdir kernfs_drain_open_files cgroup_file_release cgroup_pressure_release psi_trigger_destroy wake_up_pollfree(&t->event_wait) // vfs_poll is unblocked synchronize_rcu kfree(t) poll_freewait -> UAF access to the trigger's waitqueue head Patch [1] fixed this issue for epoll() case using wake_up_pollfree(), however the same issue exists for synchronous poll() case. The root cause of this issue is that the lifecycles of the psi trigger's waitqueue and of the file associated with the trigger are different. Fix this by using kernfs_generic_poll function when polling on cgroup-specific psi triggers. It internally uses kernfs_open_node->poll waitqueue head with its lifecycle tied to the file's lifecycle. This also renders the fix in [1] obsolete, so revert it. [1] commit c2dbe32d5db5 ("sched/psi: Fix use-after-free in ep_remove_wait_queue()")
CVE-2023-54019
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-2023-54019
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": "0e94682b73bfa6c44c98af7a26771c9c08c055d5",
"lessThan": "92cc0153324b6ae8577a39f5bf2cd83c9a34ea6a",
"versionType": "git"
},
{
"status": "affected",
"version": "0e94682b73bfa6c44c98af7a26771c9c08c055d5",
"lessThan": "d124ab17024cc85a1079b7810a018a497ebc13da",
"versionType": "git"
},
{
"status": "affected",
"version": "0e94682b73bfa6c44c98af7a26771c9c08c055d5",
"lessThan": "aff037078ecaecf34a7c2afab1341815f90fba5e",
"versionType": "git"
}
],
"programFiles": [
"include/linux/psi.h",
"include/linux/psi_types.h",
"kernel/cgroup/cgroup.c",
"kernel/sched/psi.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.42",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.4.7",
"versionType": "semver",
"lessThanOrEqual": "6.4.*"
},
{
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/psi.h",
"include/linux/psi_types.h",
"kernel/cgroup/cgroup.c",
"kernel/sched/psi.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2023-54019
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30334 · Revision 1
- Added to Heist Feed
- Publisher date