Linux Kernel up to 7.2.12 stmmac dwmac1000_irq_status resource consumption

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.2.12. It has been declared as problematic. This affects the function dwmac1000_irq_status of the component stmmac. Executing a manipulation can lead to resource consumption. This vulnerability is registered as CVE-2026-99188. The attack needs to be launched locally. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.12. It has been declared as problematic. This vulnerability affects the function dwmac1000_irq_status of the component stmmac. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: dwmac1000: clear the RGMII status interrupt Since commit 2e2c878a3141 ("net: stmmac: remove SGMII/RGMII/SMII interrupt handling") nothing on the RGMII path reads GMAC_RGSMIIIS, so RGSMIIIS stays pending behind GMAC_INT_MASK from the first link change on. stmmac_resume() resets the MAC in stmmac_hw_setup(); the reset sets GMAC_INT_MASK to 0 until dwmac1000_core_init() writes the mask again, and the pending status storms the line: dwmac_dma_interrupt: unexpected status 04000000 A register dump at the first message on ODROID-HC4 showed it: core int_status 00000001 int_mask 00000000 pmt 00000000 rgsmiiis 0000000d When the resume thread runs on the CPU that takes the MAC interrupt, the storm starves it: a soft lockup, then a watchdog reset or a hang. Read GMAC_RGSMIIIS in dwmac1000_irq_status() when the status is not masked, as the driver did before 2e2c878a3141; the read clears it. Wake-on-LAN resume from s2idle with the resume thread and the MAC interrupt on one CPU: Helios64 (dwmac-rk), 7.3-rc6, soft-locked in 3 of 3 resumes without a fix and in 0 of 10 with this patch; it ran with an out-of-tree dwmac-rk change that keeps the GMAC powered across suspend. ODROID-HC4 (dwmac-meson8b): 0 of 10 with this patch, 2 of 2 without a fix on a 7.3-rc5 build. irq_rgmii_n went up by one per resume.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-99188 since 09/25/2026. The exploitation appears to be easy. Local access is required to approach this attack. The exploitation requires an enhanced level of successful authentication. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

Upgrading to version 7.2.13 eliminates this vulnerability. Applying the patch affc6d572935282ef9ab1e0b790cbc31e5ad8bca/aa07285705f8d5bac464eb1c5b7412f8e88b91e1 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.2.10
• 7.2.11
• 7.2.12

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

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