CVE-2023-52832 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: don't return unset power in ieee80211_get_tx_power()
We can get a UBSAN warning if ieee80211_get_tx_power() returns the INT_MIN value mac80211 internally uses for "unset power level".
UBSAN: signed-integer-overflow in net/wireless/nl80211.c:3816:5 -2147483648 * 100 cannot be represented in type 'int' CPU: 0 PID: 20433 Comm: insmod Tainted: G WC OE Call Trace: dump_stack+0x74/0x92 ubsan_epilogue+0x9/0x50 handle_overflow+0x8d/0xd0 __ubsan_handle_mul_overflow+0xe/0x10 nl80211_send_iface+0x688/0x6b0 [cfg80211]
[...]
cfg80211_register_wdev+0x78/0xb0 [cfg80211]
cfg80211_netdev_notifier_call+0x200/0x620 [cfg80211]
[...]
ieee80211_if_add+0x60e/0x8f0 [mac80211]
ieee80211_register_hw+0xda5/0x1170 [mac80211]
In this case, simply return an error instead, to indicate that no data is available.
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Analysis
by VulDB Data Team • 01/05/2026
The vulnerability identified as CVE-2023-52832 resides within the Linux kernel's mac80211 wireless subsystem, specifically affecting the ieee80211_get_tx_power() function. This flaw represents a critical integer overflow condition that can manifest during wireless network interface initialization and configuration operations. The issue stems from the function's improper handling of unset power level values, where it returns INT_MIN (−2,147,483,648) to indicate an uninitialized state. When this value gets processed by the nl80211 subsystem for wireless configuration, the unsigned integer sanitizer (UBSAN) detects an arithmetic overflow during multiplication operations, specifically when attempting to scale the power value by 100. This overflow condition occurs because the system attempts to multiply the minimum integer value by 100, which exceeds the maximum representable value for a signed 32-bit integer, triggering the UBSAN warning and potential system instability.
The technical implementation of this vulnerability demonstrates a classic case of improper error handling and value validation within kernel space wireless drivers. The mac80211 subsystem internally uses INT_MIN as a sentinel value to denote unset power levels, but the ieee80211_get_tx_power() function fails to properly distinguish between legitimate power values and this special unset indicator. When the nl80211.c module processes this return value, it attempts to perform arithmetic operations on what should be an invalid state, causing the signed integer overflow. This behavior creates a pathway for potential denial of service conditions or system crashes during wireless interface registration and configuration, particularly when kernel modules are loaded or wireless devices are initialized. The call trace shows the vulnerability propagating through the wireless configuration framework, from the initial module loading through the interface addition process to the final registration call, indicating the widespread impact across the wireless subsystem.
The operational impact of CVE-2023-52832 extends beyond simple system instability to potentially compromise wireless network functionality and system reliability. When this vulnerability is triggered, it can cause the kernel to panic or enter an undefined state during wireless interface initialization, preventing legitimate wireless communication from establishing properly. This creates a denial of service condition for wireless network operations, affecting devices that rely on kernel-level wireless capabilities for connectivity. The vulnerability affects systems running Linux kernels with mac80211 wireless subsystem implementations, particularly those that dynamically configure wireless interfaces or load wireless drivers. The issue is particularly concerning in embedded systems, IoT devices, and server environments where wireless connectivity is essential for management or communication purposes. Attackers could potentially exploit this vulnerability to disrupt wireless services or force system reboots, though direct remote code execution is not typically possible due to the kernel space nature of the flaw.
Mitigation strategies for CVE-2023-52832 focus on proper error handling and value validation within the kernel wireless subsystem. The recommended fix involves modifying the ieee80211_get_tx_power() function to return an explicit error code when encountering unset power levels, rather than returning the INT_MIN sentinel value. This approach aligns with the principle of defensive programming and proper error state management as outlined in CWE-398, which addresses code quality issues related to improper error handling. Organizations should prioritize updating their Linux kernel versions to include the patched implementation that prevents the return of unset power values to the nl80211 subsystem. System administrators should monitor wireless interface initialization processes and ensure that kernel updates are applied promptly to prevent exploitation. The fix also aligns with ATT&CK technique T1499.004, which involves system disruption through kernel-level modifications, by addressing the root cause that enables such disruptions. Additionally, implementing proper logging and monitoring of wireless subsystem initialization failures can help detect potential exploitation attempts or indicate when systems are vulnerable to this class of integer overflow conditions.