CVE Catalog

CVE-2026-74738

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the regmap sdw-mbq module has a vulnerability of calling an unset readable_reg callback. When the callback is not set, calling it leads to a NULL pointer dereference, potentially causing a system crash.

Risk Assessment

The vulnerability could be exploited to cause a system crash during register operations, threatening system availability.

Recommendation

Apply the kernel patch that treats a missing callback as all registers readable, and update the system.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: regmap: sdw-mbq: don't call an unset readable_reg callback regmap_sdw_mbq_poll_busy() decides whether to poll the Function Busy bit by calling ctx->readable_reg(), which is a straight copy of config->readable_reg. That callback is optional: regmap_readable() treats a NULL ->readable_reg as "every register is readable", and drivers rely on that. es9356 and tac5xx2-sdw both build an MBQ regmap without one. Since commit ca1b11b36d82 ("regmap: sdw-mbq: Allow defers on undeferrable controls") the poll runs on every -ENODATA, not only for Controls the driver marked deferrable, so any of those devices answering COMMAND_IGNORED takes the kernel through a NULL function pointer. Treat a missing callback the way the rest of regmap does and poll.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS