CVE 설명

In the Linux kernel, the following vulnerability has been resolved: net/smc: protect clcsock lifetime in smc_getname smc_getname() dereferences smc->clcsock without holding clcsock_release_lock. Link-group termination can release the CLC socket through smc_close_active_abort() while the SMC socket is still open, for example after shutdown(SHUT_WR). A getsockname() caller can load smc->clcsock, then the termination worker can clear the pointer and call sock_release() before the caller accesses clcsock->ops or invokes getname(). This causes a use-after-free; if the worker clears the pointer before the load, it causes a NULL dereference. The syscall's file reference keeps the SMC socket alive but does not prevent asynchronous release of its CLC socket. KASAN reported the following with test-only timing instrumentation: BUG: KASAN: slab-use-after-free in smc_getname+0x19e/0x1b0 Read of size 8 at addr ffff888109abb4e0 by task poc/103 Call Trace: smc_getname+0x19e/0x1b0 do_getsockname+0xe5/0x170 __sys_getsockname+0x8c/0x100 Allocated by task 95: sock_alloc_inode+0x1e/0x280 sock_alloc+0x3d/0x240 __sock_create+0x7e/0x430 smc_create+0x121/0x240 Freed by task 0: kmem_cache_free+0xcc/0x340 rcu_core+0x50a/0x1850 Last potentially related work creation: evict+0x446/0x6c0 smc_clcsock_release+0xa8/0xd0 smc_close_active_abort+0x26a/0x3a0 __smc_lgr_terminate.part.0+0x137/0x2e0 Hold clcsock_release_lock across the pointer check and the getname() callback to serialize with smc_clcsock_release(). Return -EBADF if the CLC socket has already been released, preserving the existing peer state check and the callback's return value otherwise.

CVE 정보

메트릭

메트릭	점수	심각도	CVSS 벡터	출처
V3.1	7.8	HIGH	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 추가 정보 Base: Exploitabilty Metrics The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Local The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. Low The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope Metrics The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact Metrics The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. High There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. High There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal Metrics The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental Metrics These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.	416baaa9-dc9f-4396-8d5f-8c081fb06d67