CVE-2026-98015
net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put
Description
In the Linux kernel, the following vulnerability has been resolved: net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put In mlx5_eswitch_termtbl_put(), the zero-ref cleanup check reads tt->ref_count after termtbl_mutex has been released. Two concurrent callers on the same mlx5_termtbl_handle race: one decrements ref_count to zero, removes the hash entry, and calls kfree(tt) while the other has already dropped the mutex and is about to evaluate if (!tt->ref_count), producing a use-after-free. Fix this by capturing the result of the decrement into a stack-local last variable before dropping the mutex. The cleanup decision is now made entirely under termtbl_mutex, and tt is not touched after kfree.
INFO
Published Date :
Sept. 25, 2026, 11:17 a.m.
Last Modified :
Sept. 25, 2026, 11:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Capture refcount result before releasing mutex.
- Ensure cleanup decision is made under mutex.
- Apply kernel patch for mlx5 E-Switch.
References to Advisories, Solutions, and Tools
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CVE-2026-98015.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-98015 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-98015
weaknesses.
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 25, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put In mlx5_eswitch_termtbl_put(), the zero-ref cleanup check reads tt->ref_count after termtbl_mutex has been released. Two concurrent callers on the same mlx5_termtbl_handle race: one decrements ref_count to zero, removes the hash entry, and calls kfree(tt) while the other has already dropped the mutex and is about to evaluate if (!tt->ref_count), producing a use-after-free. Fix this by capturing the result of the decrement into a stack-local last variable before dropping the mutex. The cleanup decision is now made entirely under termtbl_mutex, and tt is not touched after kfree. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98015.json">CVE-2026-98015</a> Added Reference https://git.kernel.org/stable/c/18b2969073879b9cce24e1a78b118bdad54518d1 Added Reference https://git.kernel.org/stable/c/304ea40ef4561671503c36e47da44a0a31b71e36 Added Reference https://git.kernel.org/stable/c/7ee07f601f8f507c9faf25c68a49396ab8950596 Added Reference https://git.kernel.org/stable/c/e393789e92310d7c66f57c876101779c90816a12