CVE-2024-46834 in Linux
Summary
by MITRE • 09/27/2024
In the Linux kernel, the following vulnerability has been resolved:
ethtool: fail closed if we can't get max channel used in indirection tables
Commit 0d1b7d6c9274 ("bnxt: fix crashes when reducing ring count with active RSS contexts") proves that allowing indirection table to contain channels with out of bounds IDs may lead to crashes. Currently the max channel check in the core gets skipped if driver can't fetch the indirection table or when we can't allocate memory.
Both of those conditions should be extremely rare but if they do happen we should try to be safe and fail the channel change.
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Analysis
by VulDB Data Team • 04/04/2026
The vulnerability described in CVE-2024-46834 represents a critical flaw in the Linux kernel's ethtool implementation that affects network driver channel management and RSS (Receive Side Scaling) configuration. This issue specifically targets the bnxt driver and similar network interface implementations where the kernel fails to properly validate channel identifiers within indirection tables during runtime configuration changes. The vulnerability stems from inadequate error handling mechanisms that permit potentially malformed channel configurations to proceed without proper validation, creating a potential pathway for system instability and crash conditions.
The technical flaw manifests when the kernel attempts to modify network channel configurations while processing RSS indirection tables. Under normal operating conditions, the kernel performs validation checks to ensure that channel identifiers referenced in these tables remain within acceptable bounds. However, when the driver cannot retrieve the current indirection table or encounters memory allocation failures during this process, the validation logic is bypassed entirely. This failure to validate channel IDs results in a dangerous scenario where invalid channel references can be processed, leading to memory corruption and system crashes as demonstrated in the referenced commit 0d1b7d6c9274.
The operational impact of this vulnerability extends beyond simple system crashes to encompass potential denial of service conditions that can affect network connectivity and system stability. Network administrators and system operators may experience unexpected service interruptions when network channel configurations are modified, particularly during high-traffic periods or when dynamic resource allocation occurs. The vulnerability affects the core networking stack's ability to maintain consistent channel state management, which can result in complete network interface failures and require manual intervention to restore normal operations. This flaw particularly impacts environments where dynamic network configuration changes occur frequently, such as cloud computing platforms, virtualized environments, and high-performance networking deployments.
The security implications of this vulnerability align with CWE-129, which addresses improper validation of array indices and other input validation issues. The flaw represents a classic case of fail-open security model where error conditions should trigger protective mechanisms rather than allowing potentially dangerous operations to proceed. From an ATT&CK framework perspective, this vulnerability could be leveraged in privilege escalation scenarios or as part of broader attack chains targeting system stability and availability. The vulnerability's remediation requires implementing fail-closed behavior where any error condition during indirection table processing results in immediate rejection of the channel change request, preventing invalid configurations from being applied to the network subsystem.
Mitigation strategies should focus on implementing comprehensive error handling and validation protocols within the kernel's network subsystem. System administrators should prioritize applying the relevant kernel patches that enforce strict validation of channel identifiers and ensure proper error handling during indirection table operations. Additionally, monitoring systems should be configured to detect unusual network interface behavior or configuration changes that might indicate this vulnerability's exploitation. Regular kernel updates and security audits of network configurations are essential to prevent exploitation of this vulnerability, particularly in mission-critical environments where network availability is paramount. The fix implemented in the referenced commit demonstrates the importance of defensive programming practices in kernel space where error conditions must be handled gracefully to maintain system integrity and prevent potential exploitation by malicious actors.