Bug 2436788 (CVE-2026-23058)
| Summary: | CVE-2026-23058 kernel: Linux kernel: Denial of Service in ems_usb CAN USB driver due to memory leak | ||
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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 | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
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| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's ems_usb Controller Area Network (CAN) Universal Serial Bus (USB) driver. A local user with access to the CAN network interface can repeatedly trigger open and close cycles, leading to a memory leak. This occurs because completed USB Request Blocks (URBs) are unanchored by the USB core before the completion callback runs, preventing proper cleanup. Over time, this resource exhaustion can lead to a denial of service.
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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: | |
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In the Linux kernel, the following vulnerability has been resolved: can: ems_usb: ems_usb_read_bulk_callback(): fix URB memory leak Fix similar memory leak as in commit 7352e1d5932a ("can: gs_usb: gs_usb_receive_bulk_callback(): fix URB memory leak"). In ems_usb_open(), the URBs for USB-in transfers are allocated, added to the dev->rx_submitted anchor and submitted. In the complete callback ems_usb_read_bulk_callback(), the URBs are processed and resubmitted. In ems_usb_close() the URBs are freed by calling usb_kill_anchored_urbs(&dev->rx_submitted). However, this does not take into account that the USB framework unanchors the URB before the complete function is called. This means that once an in-URB has been completed, it is no longer anchored and is ultimately not released in ems_usb_close(). Fix the memory leak by anchoring the URB in the ems_usb_read_bulk_callback() to the dev->rx_submitted anchor.