Description
In the Linux kernel, the following vulnerability has been resolved: spi: cadence-quadspi: Parse DT for flashes with the rest of the DT parsing The recent refactoring of where runtime PM is enabled done in commit f1eb4e792bb1 ("spi: spi-cadence-quadspi: Enable pm runtime earlier to avoid imbalance") made the fact that when we do a pm_runtime_disable() in the error paths of probe() we can trigger a runtime disable which in turn results in duplicate clock disables. This is particularly likely to happen when there is missing or broken DT description for the flashes attached to the controller. Early on in the probe function we do a pm_runtime_get_noresume() since the probe function leaves the device in a powered up state but in the error path we can't assume that PM is enabled so we also manually disable everything, including clocks. This means that when runtime PM is active both it and the probe function release the same reference to the main clock for the IP, triggering warnings from the clock subsystem: [ 8.693719] clk:75:7 already disabled [ 8.693791] WARNING: CPU: 1 PID: 185 at /usr/src/kernel/drivers/clk/clk.c:1188 clk_core_disable+0xa0/0xb ... [ 8.694261] clk_core_disable+0xa0/0xb4 (P) [ 8.694272] clk_disable+0x38/0x60 [ 8.694283] cqspi_probe+0x7c8/0xc5c [spi_cadence_quadspi] [ 8.694309] platform_probe+0x5c/0xa4 Dealing with this issue properly is complicated by the fact that we don't know if runtime PM is active so can't tell if it will disable the clocks or not. We can, however, sidestep the issue for the flash descriptions by moving their parsing to when we parse the controller properties which also save us doing a bunch of setup which can never be used so let's do that.
Product status
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 08dca4c8099a41a9fa3be128a793387603f73a17
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before dcaa104ad9c860a6dbd5797919e0ec0b1cd5a57a
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (git) before 9f0736a4e136a6eb61e0cf530ddc18ab6d816ba3
6.18.16 (semver)
6.19.6 (semver)
7.0 (original_commit_for_fix)
References
git.kernel.org/...c/08dca4c8099a41a9fa3be128a793387603f73a17
git.kernel.org/...c/dcaa104ad9c860a6dbd5797919e0ec0b1cd5a57a
git.kernel.org/...c/9f0736a4e136a6eb61e0cf530ddc18ab6d816ba3