In the Linux kernel, the following vulnerability has been resolved: gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock Locking is disabled in the regmap config as this driver uses its own lock. This means that all calls to regmap functions (read or write) must hold the i2c_lock. The function pca953x_irq_bus_sync_unlock() did not do this, and it was therefore possible that multiple threads could cause an incorrect register to be read/written. A previous patch partly fixed this, but only protected the write to the interrupt mask register, and not the read from the direction register.
https://git.kernel.org/stable/c/e6a2f5f845f50b0c4299bace5111f56d3390a090
https://git.kernel.org/stable/c/bf3f37c2d40b51deb79aea910f28999d7c8c6b5a
https://git.kernel.org/stable/c/9dc325327babe7f159e84cbe9380a45342da0585
https://git.kernel.org/stable/c/5d05c4252c09ce10624be2197853c80bf87424e4
https://git.kernel.org/stable/c/41255e64eb9dd87b0b8675f4e47a9c67bcef6e39