CVE-2022-50279

wifi: rtlwifi: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit()

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Published Sep 15, 2025 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

wifi: rtlwifi: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit()

There is a global-out-of-bounds reported by KASAN:

BUG: KASAN: global-out-of-bounds in
_rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411

CPU: 6 PID: 411 Comm: NetworkManager Tainted: G D
6.1.0-rc8+ #144 e15588508517267d37
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
Call Trace:
<TASK>
...
kasan_report+0xbb/0x1c0
_rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae]
rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae]
rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae]
...
</TASK>

The root cause of the problem is that the comparison order of
"prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The
_rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two
strings from tail to head, which causes the problem. In the
_rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet
this requirement by carefully designing the comparison order.
For example, "pregulation" and "pbandwidth" are compared in order of
length from small to large, first is 3 and last is 4. However, the
comparison order of "prate_section" dose not obey such order requirement,
therefore when "prate_section" is "HT", when comparing from tail to head,
it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As
mentioned above, the _rtl8812ae_eq_n_byte() has the same function as
strcmp(), so just strcmp() is enough.

Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely.
Although it can be fixed by adjusting the comparison order of
"prate_section", this may cause the value of "rate_section" to not be
from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver
from staging to regular tree, but also added setting txpower limit
function during the driver config phase, so the problem was introduced
by this commit.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2022-55576 In the Linux kernel, the following vulnerability has been resolved: wifi: rtlwifi: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit() There is a global-out-of-bounds reported by KASAN: BUG: KASAN: global-out-of-bounds in _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae] Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411 CPU: 6 PID: 411 Comm: NetworkManager Tainted: G D 6.1.0-rc8+ #144 e15588508517267d37 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), Call Trace: <TASK> ... kasan_report+0xbb/0x1c0 _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae] rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae] rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae] ... </TASK> The root cause of the problem is that the comparison order of "prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The _rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two strings from tail to head, which causes the problem. In the _rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet this requirement by carefully designing the comparison order. For example, "pregulation" and "pbandwidth" are compared in order of length from small to large, first is 3 and last is 4. However, the comparison order of "prate_section" dose not obey such order requirement, therefore when "prate_section" is "HT", when comparing from tail to head, it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As mentioned above, the _rtl8812ae_eq_n_byte() has the same function as strcmp(), so just strcmp() is enough. Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely. Although it can be fixed by adjusting the comparison order of "prate_section", this may cause the value of "rate_section" to not be from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver from staging to regular tree, but also added setting txpower limit function during the driver config phase, so the problem was introduced by this commit.
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}
Type Values Removed Values Added
Weaknesses CWE-125
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

 cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: wifi: rtlwifi: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit() There is a global-out-of-bounds reported by KASAN: BUG: KASAN: global-out-of-bounds in _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae] Read of size 1 at addr ffffffffa0773c43 by task NetworkManager/411 CPU: 6 PID: 411 Comm: NetworkManager Tainted: G D 6.1.0-rc8+ #144 e15588508517267d37 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), Call Trace: <TASK> ... kasan_report+0xbb/0x1c0 _rtl8812ae_eq_n_byte.part.0+0x3d/0x84 [rtl8821ae] rtl8821ae_phy_bb_config.cold+0x346/0x641 [rtl8821ae] rtl8821ae_hw_init+0x1f5e/0x79b0 [rtl8821ae] ... </TASK> The root cause of the problem is that the comparison order of "prate_section" in _rtl8812ae_phy_set_txpower_limit() is wrong. The _rtl8812ae_eq_n_byte() is used to compare the first n bytes of the two strings from tail to head, which causes the problem. In the _rtl8812ae_phy_set_txpower_limit(), it was originally intended to meet this requirement by carefully designing the comparison order. For example, "pregulation" and "pbandwidth" are compared in order of length from small to large, first is 3 and last is 4. However, the comparison order of "prate_section" dose not obey such order requirement, therefore when "prate_section" is "HT", when comparing from tail to head, it will lead to access out of bounds in _rtl8812ae_eq_n_byte(). As mentioned above, the _rtl8812ae_eq_n_byte() has the same function as strcmp(), so just strcmp() is enough. Fix it by removing _rtl8812ae_eq_n_byte() and use strcmp() barely. Although it can be fixed by adjusting the comparison order of "prate_section", this may cause the value of "rate_section" to not be from 0 to 5. In addition, commit "21e4b0726dc6" not only moved driver from staging to regular tree, but also added setting txpower limit function during the driver config phase, so the problem was introduced by this commit.
Title wifi: rtlwifi: Fix global-out-of-bounds bug in _rtl8812ae_phy_set_txpower_limit()
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Nov 5, 2026, 8:10 PM
Reserved
Sep 15, 2025, 1:58 PM

View source JSON

Updated
Nov 5, 2026, 8:08 PM

JSON

Status
Analyzed
Published
Sep 15, 2025, 3:15 PM
Modified
Nov 5, 2026, 8:17 PM

View source JSON

Severity
Moderate
Public date
Sep 15, 2025, 12:00 AM

View source Bugzilla JSON

Updated
Sep 17, 2025, 10:07 AM

JSON