CVE-2026-74463

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> i2c: jz4780: Cache host clock rate at probe to prevent CCF prepare_lock deadlock<br /> <br /> Fix a severe AB/BA deadlock between the Common Clock Framework (CCF)<br /> and the I2C adapter lock, which triggers when an I2C-controlled clock<br /> generator client (like the Si5351) is registered or modified under the CCF.<br /> <br /> During an i2c client clock (generator) frequency change, the CCF acquires its global<br /> &amp;#39;prepare_lock&amp;#39; mutex and the driver calls i2c_transfer() to update the client&amp;#39;s<br /> chip registers, stalling for the adapter&amp;#39;s I2C bus lock.<br /> <br /> Concurrently, an independent, parallel transfer on the same bus (e.g., a GPIO<br /> expander handling LEDs) can hold the I2C adapter lock. Inside this parallel<br /> transfer path, jz4780_i2c_set_speed() calls clk_get_rate() on the host<br /> controller&amp;#39;s input clock to calculate bus timings. This call attempts to acquire<br /> the blocked CCF &amp;#39;prepare_lock&amp;#39;, creating a circular dependency that freezes<br /> the system.<br /> <br /> The jz4780 host controller clock itself is static and never changes at runtime.<br /> <br /> However, calling clk_get_rate() inside the active transfer path introduces<br /> an unnecessary dependency on the CCF internal locks.<br /> <br /> Eliminate this synchronous clk_get_rate() call from the active transfer<br /> path by caching the static host peripheral clock rate once - inside the private<br /> jz4780_i2c structure during jz4780_i2c_probe(). Update jz4780_i2c_set_speed()<br /> to use this cached value, safely decoupling active I2C transactions from the<br /> CCF internal locks without any risk of stale timings.<br /> <br /> Assisted-by web based Google AI (pinpointing the bug and writing the message).