Bug 2516985 (CVE-2026-74459)

Summary: CVE-2026-74459 kernel: can: etas_es58x: es58x_read_bulk_callback(): fix RX buffer leak on URB resubmit failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `can: etas_es58x` module. A memory leak occurs in the `es58x_read_bulk_callback()` function when an Urban Request Block (URB) resubmission fails. This failure prevents the proper release of the associated receive (RX) buffer, leading to a gradual exhaustion of system memory. This can ultimately result in a denial of service (DoS) for affected systems.
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Description OSIDB Bzimport 2026-08-15 12:43:12 UTC 
In the Linux kernel, the following vulnerability has been resolved:

can: etas_es58x: es58x_read_bulk_callback(): fix RX buffer leak on URB resubmit failure

es58x_read_bulk_callback() resubmits the RX URB after processing a received
packet. If the resubmit succeeds, the URB remains anchored and will be
handled by the normal RX path or by teardown.

However, if usb_submit_urb() fails, the callback unanchors the URB and then
returns directly. This skips the existing free_urb path, so the coherent
transfer buffer allocated with usb_alloc_coherent() is not released.

Reuse the existing free_urb path after a resubmit failure so that the RX
coherent buffer is freed before leaving the callback.
Comment 1 gkamathe 2026-08-21 09:20:44 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081532-CVE-2026-74459-bf7d@gregkh/T