Bug 2521443 (CVE-2026-74706)

Summary: CVE-2026-74706 kernel: bnge: Fix NULL pointer dereference in aux device release
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
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 bnge driver. During the setup of an auxiliary device, if the allocation of a specific resource (`auxr_dev`) fails, the subsequent release process attempts to access an unallocated memory region. This results in a NULL pointer dereference, which can lead to a system crash, causing a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-08-22 15:45:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bnge: Fix NULL pointer dereference in aux device release

If allocation of auxr_dev fails during auxiliary device setup, the error
path calls auxiliary_device_uninit(), which eventually invokes
bnge_aux_dev_release().

The release callback unconditionally dereferences aux_priv->auxr_dev->pdev
to retrieve the parent bnge_dev. Since auxr_dev has not yet been allocated
on this failure path, the dereference results in a NULL pointer exception

Retrieve the parent bnge_dev from the auxiliary device's parent instead of
auxr_dev, and free auxr_dev only when it was successfully allocated. This
allows the release callback to correctly clean up partially initialized
auxiliary devices.
Comment 1 Keith Grant 2026-08-24 17:38:29 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082237-CVE-2026-74706-889b@gregkh/T