What’s Vulnerable › Vulnerabilities

CVE-2026-90023: usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common_set_num_buffers()

• 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: 2026-09-16 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common_set_num_buffers() Previously fsg_num_buffers_validate() was removed as it was not necessary due to Kconfig setting the limits for n from 2 to 256 with default as 2. However, setting the page content in such a way that kstrtou8() reflects n value as either 0 or 1 bypasses these restrictions leading to a null pointer dereference if n is 0. Fix this by adding a check for n < 2 and returning -EINVAL if n is either 0 or 1 consistent with Kconfig logic.

Affected products

• Linux: 4.8 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/2c0f5ca48674a5b5f9fa4a9c3325aa48053af0bc
• https://git.kernel.org/stable/c/38edd187a37db0d8e4bf84cc954dbdbe7bfa366f
• https://git.kernel.org/stable/c/51cc9af4f2d3f0b765266aced66b9b532b423b13
• https://git.kernel.org/stable/c/5d56dbaeb81d5cd967cdee8ddcc70814b7139246
• https://git.kernel.org/stable/c/9e8dd2a7a8ccbb756771ad985b0ad3387ed3c957
• https://git.kernel.org/stable/c/b9b5b5df5b8dd3c1572ed267200276a44cc67d8e
• https://git.kernel.org/stable/c/e54820b9dc1d6d731ecc3e51462445dc952906a7
• https://git.kernel.org/stable/c/f4f0fe3ab47ed57ee4974fdd3e9dccb7839a7ebf

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