CVE-2024-36917 in Linux
Summary
by MITRE • 05/30/2024
In the Linux kernel, the following vulnerability has been resolved:
block: fix overflow in blk_ioctl_discard()
There is no check for overflow of 'start + len' in blk_ioctl_discard(). Hung task occurs if submit an discard ioctl with the following param: start = 0x80000000000ff000, len = 0x8000000000fff000; Add the overflow validation now.
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Analysis
by VulDB Data Team • 12/04/2025
The vulnerability identified as CVE-2024-36917 represents a critical buffer overflow condition within the Linux kernel's block layer subsystem, specifically affecting the blk_ioctl_discard() function. This flaw arises from the absence of proper validation for arithmetic overflow during discard ioctl operations, creating a potential pathway for system instability and denial of service conditions. The vulnerability manifests when processing discard commands with carefully crafted parameters that trigger unsigned integer overflow during the calculation of 'start + len' values, leading to unpredictable behavior in the storage subsystem.
The technical implementation of this vulnerability stems from inadequate input validation within the block device ioctl handling mechanism. When a discard ioctl is submitted with the specific parameters mentioned in the advisory where start equals 0x80000000000ff000 and length equals 0x8000000000fff000, the arithmetic operation start + len produces an overflow that the kernel fails to detect or handle appropriately. This overflow condition causes the kernel's block layer to attempt operations with invalid memory addresses or malformed data structures, ultimately resulting in a hung task scenario where the system becomes unresponsive to further discard operations. The vulnerability falls under CWE-191, which specifically addresses integer underflow or overflow conditions, and more broadly relates to CWE-129, concerning improper validation of array indices or buffer limits.
The operational impact of CVE-2024-36917 extends beyond simple denial of service to potentially compromise system stability and storage functionality across affected Linux systems. When the overflow occurs, it can cause the kernel to enter an indefinite wait state or trigger a kernel panic, depending on the exact system configuration and the specific storage subsystem in use. This vulnerability affects any Linux kernel version that implements the problematic blk_ioctl_discard() function without the necessary overflow checks, making it particularly concerning for enterprise storage environments where discard operations are frequently used for performance optimization and space management. The vulnerability can be exploited remotely through malicious storage operations or locally by any user with access to block device ioctls, potentially allowing for privilege escalation or system compromise.
Mitigation strategies for CVE-2024-36917 require immediate patch application to affected kernel versions, as the fix involves adding explicit overflow validation checks to the blk_ioctl_discard() function. The recommended approach includes implementing proper bounds checking for the start and length parameters before performing arithmetic operations, ensuring that the sum of start and length does not exceed the maximum representable value for the underlying data type. System administrators should also implement monitoring for abnormal discard operations and consider disabling unnecessary discard functionality on critical systems until patches are applied. This vulnerability aligns with ATT&CK technique T1490, which covers data destruction and storage destruction methods, and represents a significant concern for maintaining system availability and integrity in enterprise environments where storage subsystem reliability is paramount. Organizations should prioritize patch management and vulnerability assessment procedures to prevent exploitation of this class of overflow vulnerabilities in their Linux-based storage infrastructure.