CVE 설명

In the Linux kernel, the following vulnerability has been resolved: forcedeth: fix off-by-one when saving/restoring non-PCI config space nv_suspend() and nv_resume() walk the non-PCI configuration space with for (i = 0; i <= np->register_size/sizeof(u32); i++) which runs one iteration too many. saved_config_space is declared as u32 saved_config_space[NV_PCI_REGSZ_MAX/4]; and NV_PCI_REGSZ_VER3 is equal to NV_PCI_REGSZ_MAX (0x604), so on a VER3 device register_size/sizeof(u32) is exactly the array length and the last iteration addresses one element past the end. The element it lands on is np->name_rx[0..3]: saved_config_space[] is followed immediately by char name_rx[IFNAMSIZ + 3], and char needs no padding. Nothing observable is corrupted by that, because nv_request_irq() rewrites name_rx with sprintf() before it is ever passed to request_irq(). The bug is the out-of-bounds access itself, which UBSAN reports and which CONFIG_UBSAN_TRAP=y turns into a trap that aborts the running kernel code, plus an MMIO read and, on resume, an MMIO writel() to base + 0x604, one dword past the range the driver mapped: np->base = ioremap(addr, np->register_size); VER1 and VER2 devices stay inside the array, but they too get the stray read and the stray write one dword past their own window. Caught by UBSAN on an Apple Macmini3,1 (MCP79) during a deep S3 cycle. The splat below is trimmed: the build path in the file name, the CPU and taint lines, the Workqueue line, the "?" hint frames, and the frames below device_suspend are all cut. The kernel was tainted, with an out-of-tree nouveau and CPU_OUT_OF_SPEC; forcedeth itself was the stock module. UBSAN: array-index-out-of-bounds in drivers/net/ethernet/nvidia/forcedeth.c:6225:25 index 385 is out of range for type 'u32 [385]' Call Trace: dump_stack_lvl+0x5d/0x80 ubsan_epilogue+0x5/0x2b __ubsan_handle_out_of_bounds.cold+0x54/0x59 __this_module+0xe398c/0xe9010 [forcedeth] pci_pm_suspend+0x80/0x170 dpm_run_callback+0x51/0x160 device_suspend+0x1a2/0x4a0 ... Both loops are hit. UBSAN reports each source location only once per module load (__ubsan_handle_out_of_bounds() calls suppress_report(), which does test_and_set_bit(REPORTED_BIT, ...) on the struct source_location), so the two splats land in the first S3 cycle after the module is loaded and later cycles are silent even though the access still runs off the end every time. In that first cycle line 6225 is reported from pci_pm_suspend and line 6240 from pci_pm_resume. The same off-by-one was fixed in nv_get_regs() by commit ba9aa134287f ("forcedeth: fix buffer overflow") in 2012; these two loops were missed. The suspend and resume side was reported on LKML in September 2013 by Marc Weber, with the same analysis and the same one-character fix, but the patch was attached rather than sent inline and the thread ended there. Use < instead of <=, which saves and restores exactly register_size bytes.

CVE 정보

메트릭

메트릭	점수	심각도	CVSS 벡터	출처
V3.1	7.1	HIGH	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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. None There is no loss of confidentiality within the impacted component. 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