iio: adc: ade9000: fix NULL pointer dereference in clkout registration

Overview

In the Linux kernel, the following vulnerability has been resolved:

iio: adc: ade9000: fix NULL pointer dereference in clkout registration

ade9000_setup_clkout() passes NULL as the register address when registering a divider clock. During clock registration, the common clock framework calls clk_divider_recalc_rate(), which dereferences the address through readl(). As a result, probing an ADE9000 configured as a clock provider with an external input clock crashes.

CLKOUT passes CLKIN through without changing its rate. Register it as a 1:1 fixed-factor clock, which does not require register access.

This change does not affect the configuration using the internal clock, for which the driver does not register a clock provider.

Affected

• Linux >= 81de7b4619fc3682a3bedaa7e8d6b2d67ab4e10a < d2400175228fbc10b29c49a7b5f70a7e80d144dd
• Linux >= 81de7b4619fc3682a3bedaa7e8d6b2d67ab4e10a < 134aa31a8d4e71f6ab1d155ad7b4502508832f72
• Linux >= 81de7b4619fc3682a3bedaa7e8d6b2d67ab4e10a < 49ee1c6a3ebda6b7de06b2961b0e09c1c3fe536a
• Linux 6.18

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.