Bug 2300424 (CVE-2024-41051)
| Summary: | CVE-2024-41051 kernel: cachefiles: wait for ondemand_object_worker to finish when dropping object | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | dfreiber, drow, jburrell, vkumar |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | kernel 6.1.100, kernel 6.6.41, kernel 6.9.10, kernel 6.10 | Doc Type: | If docs needed, set a value |
| Doc Text: |
A use-after-free vulnerability was identified in the Linux kernel's cachefiles subsystem. When an object was freed, there was a risk that a queued worker (ondemand_object_worker()) could still attempt to access this freed object, leading to potential undefined behavior and security issues.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 2301583 | ||
| Bug Blocks: | |||
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024072927-CVE-2024-41051-f511@gregkh/T Created kernel tracking bugs for this issue: Affects: fedora-all [bug 2301583] |
In the Linux kernel, the following vulnerability has been resolved: cachefiles: wait for ondemand_object_worker to finish when dropping object When queuing ondemand_object_worker() to re-open the object, cachefiles_object is not pinned. The cachefiles_object may be freed when the pending read request is completed intentionally and the related erofs is umounted. If ondemand_object_worker() runs after the object is freed, it will incur use-after-free problem as shown below. process A processs B process C process D cachefiles_ondemand_send_req() // send a read req X // wait for its completion // close ondemand fd cachefiles_ondemand_fd_release() // set object as CLOSE cachefiles_ondemand_daemon_read() // set object as REOPENING queue_work(fscache_wq, &info->ondemand_work) // close /dev/cachefiles cachefiles_daemon_release cachefiles_flush_reqs complete(&req->done) // read req X is completed // umount the erofs fs cachefiles_put_object() // object will be freed cachefiles_ondemand_deinit_obj_info() kmem_cache_free(object) // both info and object are freed ondemand_object_worker() When dropping an object, it is no longer necessary to reopen the object, so use cancel_work_sync() to cancel or wait for ondemand_object_worker() to finish.