Bug 2493742 (CVE-2026-53286)

Summary: CVE-2026-53286 kernel: idpf: fix double free and use-after-free in aux device error paths
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. Specifically, a double free and use-after-free vulnerability exists in the `idpf` driver's auxiliary device error paths. This flaw occurs when `auxiliary_device_add()` fails, leading to improper memory handling where memory is freed twice or accessed after being freed. This can result in system instability, denial of service (DoS), or potentially lead to arbitrary code execution.
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Description OSIDB Bzimport 2026-06-26 21:04:35 UTC
In the Linux kernel, the following vulnerability has been resolved:

idpf: fix double free and use-after-free in aux device error paths

When auxiliary_device_add() fails in idpf_plug_vport_aux_dev() or
idpf_plug_core_aux_dev(), the err_aux_dev_add label calls
auxiliary_device_uninit() and falls through to err_aux_dev_init.  The
uninit call will trigger put_device(), which invokes the release
callback (idpf_vport_adev_release / idpf_core_adev_release) that frees
iadev.  The fall-through then reads adev->id from the freed iadev for
ida_free() and double-frees iadev with kfree().

Free the IDA slot and clear the back-pointer before uninit, while adev
is still valid, then return immediately.

Commit 65637c3a1811 ("idpf: fix UAF in RDMA core aux dev deinitialization")
fixed the same use-after-free in the matching unplug path in this file but
missed both probe error paths.

Comment 1 Mauro Matteo Cascella 2026-06-29 09:09:32 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062616-CVE-2026-53286-b01e@gregkh/T