CVE Descriptions

In the Linux kernel, the following vulnerability has been resolved: ice: fix NULL pointer dereference in ice_reset_all_vfs() ice_reset_all_vfs() ignores the return value of ice_vf_rebuild_vsi(). When the VSI rebuild fails (e.g. during NVM firmware update via nvmupdate64e), ice_vsi_rebuild() tears down the VSI on its error path, leaving txq_map and rxq_map as NULL. The subsequent unconditional call to ice_vf_post_vsi_rebuild() leads to a NULL pointer dereference in ice_ena_vf_q_mappings() when it accesses vsi->txq_map[0]. The single-VF reset path in ice_reset_vf() already handles this correctly by checking the return value of ice_vf_reconfig_vsi() and skipping ice_vf_post_vsi_rebuild() on failure. Apply the same pattern to ice_reset_all_vfs(): check the return value of ice_vf_rebuild_vsi() and skip ice_vf_post_vsi_rebuild() and ice_eswitch_attach_vf() on failure. The VF is left safely disabled (ICE_VF_STATE_INIT not set, VFGEN_RSTAT not set to VFACTIVE) and can be recovered via a VFLR triggered by a PCI reset of the VF (sysfs reset or driver rebind). Note that this patch does not prevent the VF VSI rebuild from failing during NVM update — the underlying cause is firmware being in a transitional state while the EMP reset is processed, which can cause Admin Queue commands (ice_add_vsi, ice_cfg_vsi_lan) to fail. This patch only prevents the subsequent NULL pointer dereference that crashes the kernel when the rebuild does fail. crash> bt PID: 50795 TASK: ff34c9ee708dc680 CPU: 1 COMMAND: "kworker/u512:5" #0 [ff72159bcfe5bb50] machine_kexec at ffffffffaa8850ee #1 [ff72159bcfe5bba8] __crash_kexec at ffffffffaaa15fba #2 [ff72159bcfe5bc68] crash_kexec at ffffffffaaa16540 #3 [ff72159bcfe5bc70] oops_end at ffffffffaa837eda #4 [ff72159bcfe5bc90] page_fault_oops at ffffffffaa893997 #5 [ff72159bcfe5bce8] exc_page_fault at ffffffffab528595 #6 [ff72159bcfe5bd10] asm_exc_page_fault at ffffffffab600bb2 [exception RIP: ice_ena_vf_q_mappings+0x79] RIP: ffffffffc0a85b29 RSP: ff72159bcfe5bdc8 RFLAGS: 00010206 RAX: 00000000000f0000 RBX: ff34c9efc9c00000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000010 RDI: ff34c9efc9c00000 RBP: ff34c9efc27d4828 R8: 0000000000000093 R9: 0000000000000040 R10: ff34c9efc27d4828 R11: 0000000000000040 R12: 0000000000100000 R13: 0000000000000010 R14: R15: ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ff72159bcfe5bdf8] ice_sriov_post_vsi_rebuild at ffffffffc0a85e2e [ice] #8 [ff72159bcfe5be08] ice_reset_all_vfs at ffffffffc0a920b4 [ice] #9 [ff72159bcfe5be48] ice_service_task at ffffffffc0a31519 [ice] #10 [ff72159bcfe5be88] process_one_work at ffffffffaa93dca4 #11 [ff72159bcfe5bec8] worker_thread at ffffffffaa93e9de #12 [ff72159bcfe5bf18] kthread at ffffffffaa946663 #13 [ff72159bcfe5bf50] ret_from_fork at ffffffffaa8086b9 The panic occurs attempting to dereference the NULL pointer in RDX at ice_sriov.c:294, which loads vsi->txq_map (offset 0x4b8 in ice_vsi). The faulting VSI is an allocated slab object but not fully initialized after a failed ice_vsi_rebuild(): crash> struct ice_vsi 0xff34c9efc27d4828 netdev = 0x0, rx_rings = 0x0, tx_rings = 0x0, q_vectors = 0x0, txq_map = 0x0, rxq_map = 0x0, alloc_txq = 0x10, num_txq = 0x10, alloc_rxq = 0x10, num_rxq = 0x10, The nvmupdate64e process was performing NVM firmware update: crash> bt 0xff34c9edd1a30000 PID: 49858 TASK: ff34c9edd1a30000 CPU: 1 COMMAND: "nvmupdate64e" #0 [ff72159bcd617618] __schedule at ffffffffab5333f8 #4 [ff72159bcd617750] ice_sq_send_cmd at ffffffffc0a35347 [ice] #5 [ff72159bcd6177a8] ice_sq_send_cmd_retry at ffffffffc0a35b47 [ice] #6 [ff72159bcd617810] ice_aq_send_cmd at ffffffffc0a38018 [ice] #7 [ff72159bcd617848] ice_aq_read_nvm at ffffffffc0a40254 [ice] #8 ---truncated---

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-476	NULL Pointer Dereference The product dereferences a pointer that it expects to be valid but is NULL.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.1	5.5	MEDIUM	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H More informations 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. None There is no loss of integrity within 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.	nvd@nist.gov