CVE-2020-36776thermal/drivers/cpufreq_cooling: Fix slab OOB issue

Official description

In the Linux kernel, the following vulnerability has been resolved: thermal/drivers/cpufreq_cooling: Fix slab OOB issue Slab OOB issue is scanned by KASAN in cpu_power_to_freq(). If power is limited below the power of OPP0 in EM table, it will cause slab out-of-bound issue with negative array index. Return the lowest frequency if limited power cannot found a suitable OPP in EM table to fix this issue. Backtrace: [<ffffffd02d2a37f0>] die+0x104/0x5ac [<ffffffd02d2a5630>] bug_handler+0x64/0xd0 [<ffffffd02d288ce4>] brk_handler+0x160/0x258 [<ffffffd02d281e5c>] do_debug_exception+0x248/0x3f0 [<ffffffd02d284488>] el1_dbg+0x14/0xbc [<ffffffd02d75d1d4>] __kasan_report+0x1dc/0x1e0 [<ffffffd02d75c2e0>] kasan_report+0x10/0x20 [<ffffffd02d75def8>] __asan_report_load8_noabort+0x18/0x28 [<ffffffd02e6fce5c>] cpufreq_power2state+0x180/0x43c [<ffffffd02e6ead80>] power_actor_set_power+0x114/0x1d4 [<ffffffd02e6fac24>] allocate_power+0xaec/0xde0 [<ffffffd02e6f9f80>] power_allocator_throttle+0x3ec/0x5a4 [<ffffffd02e6ea888>] handle_thermal_trip+0x160/0x294 [<ffffffd02e6edd08>] thermal_zone_device_check+0xe4/0x154 [<ffffffd02d351cb4>] process_one_work+0x5e4/0xe28 [<ffffffd02d352f44>] worker_thread+0xa4c/0xfac [<ffffffd02d360124>] kthread+0x33c/0x358 [<ffffffd02d289940>] ret_from_fork+0xc/0x18

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/c24a20912eef00587416628149c438e885eb1304
• https://git.kernel.org/stable/c/876a5f33e5d961d879c5436987c09b3d9ef70379
• https://git.kernel.org/stable/c/6bf443acf6ca4f666d0e4225614ba9993a3aa1a9
• https://git.kernel.org/stable/c/34ab17cc6c2c1ac93d7e5d53bb972df9a968f085