What’s Vulnerable › Vulnerabilities

CVE-2026-90219: RDMA/cxgb4: Free debugfs on registration failure

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/cxgb4: Free debugfs on registration failure c4iw_alloc() creates the per-device debugfs tree (dev->debugfs_root via setup_debugfs()), but it is removed only in c4iw_remove(), not in c4iw_dealloc(). When RDMA device registration fails, the registration worker's err_dealloc_ctx path calls c4iw_dealloc() directly, bypassing c4iw_remove(), so the debugfs dentries leak and outlive the freed c4iw_dev. Move debugfs_remove_recursive() into c4iw_dealloc() so every path that frees ctx->dev also removes its debugfs tree.

Affected products

• Linux kernel: from 4.19.130 before 4.20; from 5.4.49 before 5.5; from 5.7.6 before 5.8; 5.8 — fixed in 4.20, 5.5, 5.8, 7.3

How to fix

Upgrade to a fixed version: Linux kernel 4.20, 5.5, 5.8, 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/046425412529dbfca1433c8bef5641b271b4ab2a
• https://git.kernel.org/stable/c/459b59f7ed56511d6529311cb4e5e482ebfcfb8e
• https://git.kernel.org/stable/c/479a7f90060e62bdd9bb4036ec0a70bf460f6d23
• https://git.kernel.org/stable/c/c332d9e7dce234d8bef78271d003a68ee943b61b
• https://git.kernel.org/stable/c/cd60992f09b7e83bfd3c76e3bb06b29f3e2fa0a8
• https://git.kernel.org/stable/c/ea41b5630fa3d9877ce9ed8832cf5575f742bfbb
• https://git.kernel.org/stable/c/f98e894ec029a752cf9c7f7834741bead0fb463d
• https://git.kernel.org/stable/c/fe5c16bb6252dea6025b748257ddc3b2665495b0

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