Bug 1412691
| Summary: | task_cwd_path results in an in-kernel memory leak | ||||||
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| Product: | Red Hat Enterprise Linux 7 | Reporter: | Kyle Walker <kwalker> | ||||
| Component: | systemtap | Assignee: | Frank Ch. Eigler <fche> | ||||
| Status: | CLOSED ERRATA | QA Contact: | Martin Cermak <mcermak> | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 7.3 | CC: | jistone, lberk, mcermak, mjw | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | Unspecified | ||||||
| OS: | Unspecified | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | systemtap-3.1-1.el7 | Doc Type: | If docs needed, set a value | ||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2017-08-01 09:34:40 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Attachments: |
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Created attachment 1239984 [details]
Patch to issue a "put_task_struct" if needed prior to the return operation.
Thanks a lot, Kyle, merged your patch upstream, and should be in the rhel7.4 rebase. @Frank, No problem at all! Thank you for the merge! - Kyle Walker Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2017:2301 |
Description of problem: The "task_cwd_path" tapset function can result in a memory leak. The function calls get_task_struct(task) early on, but does not have a corresponding put_task_struct() if the task->fs member is present. Version-Release number of selected component (if applicable): systemtap-3.0-7.el7.x86_64 How reproducible: Easily Steps to Reproduce: 1. Install systemtap required packages 2. Run the following script for a short interval $ stap -e 'probe kprocess.exit {path=fullpath_struct_path(task_cwd_path(task_current()));printf("%s\n", path)}' 3. Monitor the "KernelStack" field in /proc/meminfo over time Actual results: The "KernelStack" counter continually increases Expected results: The "KernelStack" counter increases and decreases as task_structs are created/freed. Additional info: