Bug 2347768 (CVE-2021-47633)

Summary:	CVE-2021-47633 kernel: ath5k: fix OOB in ath5k_eeprom_read_pcal_info_5111
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-02-26 03:06:04 UTC

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

ath5k: fix OOB in ath5k_eeprom_read_pcal_info_5111

The bug was found during fuzzing. Stacktrace locates it in
ath5k_eeprom_convert_pcal_info_5111.
When none of the curve is selected in the loop, idx can go
up to AR5K_EEPROM_N_PD_CURVES. The line makes pd out of bound.
pd = &chinfo[pier].pd_curves[idx];

There are many OOB writes using pd later in the code. So I
added a sanity check for idx. Checks for other loops involving
AR5K_EEPROM_N_PD_CURVES are not needed as the loop index is not
used outside the loops.

The patch is NOT tested with real device.

The following is the fuzzing report

BUG: KASAN: slab-out-of-bounds in ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
Write of size 1 at addr ffff8880174a4d60 by task modprobe/214

CPU: 0 PID: 214 Comm: modprobe Not tainted 5.6.0 #1
Call Trace:
 dump_stack+0x76/0xa0
 print_address_description.constprop.0+0x16/0x200
 ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
 ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
 __kasan_report.cold+0x37/0x7c
 ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
 kasan_report+0xe/0x20
 ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k]
 ? apic_timer_interrupt+0xa/0x20
 ? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k]
 ? ath5k_pci_eeprom_read+0x228/0x3c0 [ath5k]
 ath5k_eeprom_init+0x2513/0x6290 [ath5k]
 ? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k]
 ? usleep_range+0xb8/0x100
 ? apic_timer_interrupt+0xa/0x20
 ? ath5k_eeprom_read_pcal_info_2413+0x2f20/0x2f20 [ath5k]
 ath5k_hw_init+0xb60/0x1970 [ath5k]
 ath5k_init_ah+0x6fe/0x2530 [ath5k]
 ? kasprintf+0xa6/0xe0
 ? ath5k_stop+0x140/0x140 [ath5k]
 ? _dev_notice+0xf6/0xf6
 ? apic_timer_interrupt+0xa/0x20
 ath5k_pci_probe.cold+0x29a/0x3d6 [ath5k]
 ? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k]
 ? mutex_lock+0x89/0xd0
 ? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k]
 local_pci_probe+0xd3/0x160
 pci_device_probe+0x23f/0x3e0
 ? pci_device_remove+0x280/0x280
 ? pci_device_remove+0x280/0x280
 really_probe+0x209/0x5d0

Comment 3 Avinash Hanwate 2025-02-28 02:59:04 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022646-CVE-2021-47633-ad15@gregkh/T