CVE-2023-53752
Description
A flaw was found in the Linux kernel's networking subsystem. A local attacker can exploit an integer overflow vulnerability in the kmalloc_reserve() function by manipulating network interface settings. This can cause the kernel to attempt a memory allocation with an incorrect size, leading to memory corruption and ultimately a system crash, resulting in a Denial of Service (DoS).
Statement
A MODERATE impact flaw was found in the Linux kernel's networking subsystem. kmalloc_reserve() stores the allocation size in a 32-bit variable (obj_size): when the requested size is larger than 0x80000000, kmalloc_size_roundup() returns 2^32, which is truncated to 0, and kmalloc(0) returns ZERO_SIZE_PTR, a value that the skb allocation path does not handle. A local attacker with the privileges needed to configure network interface settings, such as setting a netdev MTU close to 0x7fffffff, could exploit this integer overflow to trigger memory corruption and a kernel crash, resulting in a denial of service. Red Hat scored this flaw 7.3 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H), lower than the CVE.org score of 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H); the difference is a lower integrity impact rating, reflecting that the established consequence is a system crash rather than controlled data modification. No Red Hat products are affected: the change that introduced this vulnerability into the RHEL 9 kernel was shipped together with its fix in the same kernel update, so the vulnerable code is not present in any released version of Red Hat Enterprise Linux 6 through 10 (kernel and kernel-rt) or Red Hat In-Vehicle OS, and all corresponding affect records are marked Not Affected with the justification that the vulnerable code is not present.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.3 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.
Availability,Other
Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.
Access Control
Technical Impact: Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.
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