Bug 1220506 (CVE-2020-36776)

Summary: VUL-0: CVE-2020-36776: kernel-source,kernel-source-azure,kernel-source-rt: thermal/drivers/cpufreq_cooling: slab OOB read in cpu_power_to_freq()
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Kernel Bugs <kernel-bugs>
Status: RESOLVED FIXED QA Contact: Security Team bot <security-team>
Severity: Minor    
Priority: P5 - None CC: carlos.lopez
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/395343/
Whiteboard: CVSSv3.1:SUSE:CVE-2020-36776:2.5:(AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-02-28 08:02:40 UTC 
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

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-36776
https://git.kernel.org/stable/c/876a5f33e5d961d879c5436987c09b3d9ef70379
https://git.kernel.org/stable/c/c24a20912eef00587416628149c438e885eb1304
https://www.cve.org/CVERecord?id=CVE-2020-36776
https://git.kernel.org/stable/c/34ab17cc6c2c1ac93d7e5d53bb972df9a968f085
https://git.kernel.org/stable/c/6bf443acf6ca4f666d0e4225614ba9993a3aa1a9
Comment 1 Carlos López 2024-02-28 08:03:20 UTC 
We have 371a3bc79c11b ("thermal/drivers/cpufreq_cooling: Fix wrong frequency converted from power") in cve/linux-5.14, SLE15-SP6, stable and master,
all of which have the fix. Closing.