{"cve":"CVE-2026-74738","nvd":{"published":"2026-08-26T15:16:52.480","modified":"2026-08-26T15:16:52.480","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nregmap: sdw-mbq: don't call an unset readable_reg callback\n\nregmap_sdw_mbq_poll_busy() decides whether to poll the Function Busy bit\nby calling ctx->readable_reg(), which is a straight copy of\nconfig->readable_reg. That callback is optional: regmap_readable() treats\na NULL ->readable_reg as \"every register is readable\", and drivers rely on\nthat. es9356 and tac5xx2-sdw both build an MBQ regmap without one.\n\nSince commit ca1b11b36d82 (\"regmap: sdw-mbq: Allow defers on undeferrable\ncontrols\") the poll runs on every -ENODATA, not only for Controls the\ndriver marked deferrable, so any of those devices answering\nCOMMAND_IGNORED takes the kernel through a NULL function pointer.\n\nTreat a missing callback the way the rest of regmap does and poll.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/00268f9452d2a0d660aa9c1bb0ca07a994af6a4f","https://git.kernel.org/stable/c/5bd8e897ecf558507142f4553e4526adfc1d6482","https://git.kernel.org/stable/c/6cf600b276a55a6481462830607a611f32e737c0"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:17.453294893+00:00"},"epss":{"cve":"CVE-2026-74738","score":0.00206,"percentile":0.1072,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}