Bug 2521492 (CVE-2026-74725)

Summary: CVE-2026-74725 kernel: enic: fix tx_hang_reset use-after-free on device removal
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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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 enic driver. During device removal, a timing issue can occur where a transmit (TX) timeout schedules a reset operation after the device's memory has been freed. This leads to a use-after-free vulnerability, a type of memory corruption where the system attempts to access memory that is no longer allocated. This can result in system instability, crashes, or potentially allow an attacker to execute arbitrary code.
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Description OSIDB Bzimport 2026-08-22 15:48:11 UTC 
In the Linux kernel, the following vulnerability has been resolved:

enic: fix tx_hang_reset use-after-free on device removal

enic_remove() cancels the reset and change_mtu_work items but does not
cancel tx_hang_reset. A TX timeout that fires while the device is being
removed can schedule enic_tx_hang_reset() so that it runs after
free_netdev(), resulting in a use-after-free.

cancel_work_sync() alone is not sufficient here: the still-live watchdog
and notify paths can re-schedule these work items in the window between
the cancel and unregister_netdev(). Use disable_work_sync(), which
cancels the work and blocks any subsequent schedule_work() from
requeuing it, and apply it to the reset and change_mtu_work items as
well so the same requeue race is closed for all teardown work.
Comment 1 gkamathe 2026-08-24 12:36:43 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082240-CVE-2026-74725-d59d@gregkh/T