Affected: Linux

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

firmware: arm_scpi: Check the DVFS OPP count returned by the firmware

Fix a kernel crash with the below call trace when the SCPI firmware returns OPP count of zero.

dvfs_info.opp_count may be zero on some platforms during the reboot test, and the kernel will crash after dereferencing the pointer to kcalloc(info->count, sizeof(*opp), GFP_KERNEL).

| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028 | Mem abort info: | ESR = 0x96000004 | Exception class = DABT (current EL), IL = 32 bits | SET = 0, FnV = 0 | EA = 0, S1PTW = 0 | Data abort info: | ISV = 0, ISS = 0x00000004 | CM = 0, WnR = 0 | user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000faefa08c | [0000000000000028] pgd=0000000000000000 | Internal error: Oops: 96000004 [#1] SMP | scpi-hwmon: probe of PHYT000D:00 failed with error -110 | Process systemd-udevd (pid: 1701, stack limit = 0x00000000aaede86c) | CPU: 2 PID: 1701 Comm: systemd-udevd Not tainted 4.19.90+ #1 | Hardware name: PHYTIUM LTD Phytium FT2000/4/Phytium FT2000/4, BIOS | pstate: 60000005 (nZCv daif -PAN -UAO) | pc : scpi_dvfs_recalc_rate+0x40/0x58 [clk_scpi] | lr : clk_register+0x438/0x720 | Call trace: | scpi_dvfs_recalc_rate+0x40/0x58 [clk_scpi] | devm_clk_hw_register+0x50/0xa0 | scpi_clk_ops_init.isra.2+0xa0/0x138 [clk_scpi] | scpi_clocks_probe+0x528/0x70c [clk_scpi…