CVE-2026-74738
Received
Received - Intake
NULL Function Pointer Dereference in Linux Kernel regmap sdw-mbq
Vulnerability report for CVE-2026-74738, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-26
Last updated on: 2026-08-26
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
