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DEBIAN-CVE-2021-47393

HighCVSS 7.1 / 10
Published May 21, 2024·Last modified Jun 15, 2026
Affected Components(0)

No affected components available

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (mlxreg-fan) Return non-zero value when fan current state is enforced from sysfs Fan speed minimum can be enforced from sysfs. For example, setting current fan speed to 20 is used to enforce fan speed to be at 100% speed, 19 - to be not below 90% speed, etcetera. This feature provides ability to limit fan speed according to some system wise considerations, like absence of some replaceable units or high system ambient temperature. Request for changing fan minimum speed is configuration request and can be set only through 'sysfs' write procedure. In this situation value of argument 'state' is above nominal fan speed maximum. Return non-zero code in this case to avoid thermal_cooling_device_stats_update() call, because in this case statistics update violates thermal statistics table range. The issues is observed in case kernel is configured with option CONFIG_THERMAL_STATISTICS. Here is the trace from KASAN: [ 159.506659] BUG: KASAN: slab-out-of-bounds in thermal_cooling_device_stats_update+0x7d/0xb0 [ 159.516016] Read of size 4 at addr ffff888116163840 by task hw-management.s/7444 [ 159.545625] Call Trace: [ 159.548366] dump_stack+0x92/0xc1 [ 159.552084] ? thermal_cooling_device_stats_update+0x7d/0xb0 [ 159.635869] thermal_zone_device_update+0x345/0x780 [ 159.688711] thermal_zone_device_set_mode+0x7d/0xc0 [ 159.694174] mlxsw_thermal_modules_init+0x48f/0x590 [mlxsw_core] [ 159.700972] ? mlxsw_thermal_set_cur_state+0x5a0/0x5a0 [mlxsw_core] [ 159.731827] mlxsw_thermal_init+0x763/0x880 [mlxsw_core] [ 160.070233] RIP: 0033:0x7fd995909970 [ 160.074239] Code: 73 01 c3 48 8b 0d 28 d5 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 99 2d 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff .. [ 160.095242] RSP: 002b:00007fff54f5d938 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 160.103722] RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 00007fd995909970 [ 160.111710] RDX: 0000000000000013 RSI: 0000000001906008 RDI: 0000000000000001 [ 160.119699] RBP: 0000000001906008 R08: 00007fd995bc9760 R09: 00007fd996210700 [ 160.127687] R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000013 [ 160.135673] R13: 0000000000000001 R14: 00007fd995bc8600 R15: 0000000000000013 [ 160.143671] [ 160.145338] Allocated by task 2924: [ 160.149242] kasan_save_stack+0x19/0x40 [ 160.153541] __kasan_kmalloc+0x7f/0xa0 [ 160.157743] __kmalloc+0x1a2/0x2b0 [ 160.161552] thermal_cooling_device_setup_sysfs+0xf9/0x1a0 [ 160.167687] __thermal_cooling_device_register+0x1b5/0x500 [ 160.173833] devm_thermal_of_cooling_device_register+0x60/0xa0 [ 160.180356] mlxreg_fan_probe+0x474/0x5e0 [mlxreg_fan] [ 160.248140] [ 160.249807] The buggy address belongs to the object at ffff888116163400 [ 160.249807] which belongs to the cache kmalloc-1k of size 1024 [ 160.263814] The buggy address is located 64 bytes to the right of [ 160.263814] 1024-byte region [ffff888116163400, ffff888116163800) [ 160.277536] The buggy address belongs to the page: [ 160.282898] page:0000000012275840 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888116167000 pfn:0x116160 [ 160.294872] head:0000000012275840 order:3 compound_mapcount:0 compound_pincount:0 [ 160.303251] flags: 0x200000000010200(slab|head|node=0|zone=2) [ 160.309694] raw: 0200000000010200 ffffea00046f7208 ffffea0004928208 ffff88810004dbc0 [ 160.318367] raw: ffff888116167000 00000000000a0006 00000001ffffffff 0000000000000000 [ 160.327033] page dumped because: kasan: bad access detected [ 160.333270] [ 160.334937] Memory state around the buggy address: [ 160.356469] >ffff888116163800: fc ..

Risk Scores
Base Score
7.1

The vulnerability requires local access to the device to be exploited. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the availability of the system.

Threat Intelligence
6.5

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
N/A

Probability that this vulnerability will be exploited in the wild within the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Related Vulnerabilities
  • CVE-2021-47393
    Upstream
  • EUVD-2021-34398
    Upstream

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