CVE-2021-47075: 
Linux Kernel vulnerability analysis and mitigation

A memory leak vulnerability was discovered in the Linux kernel's NVMe target subsystem (CVE-2021-47075). The issue occurs in the nvmet_alloc_ctrl() function when creating a controller where if the cntlid_min is larger than cntlid_max of the subsystem, the code jumps to the 'out_free_changed_ns_list' label without properly freeing ctrl->sqs memory (Kernel Git).

The vulnerability exists in the nvmet_alloc_ctrl() function within the Linux kernel's NVMe target driver. When a controller is created with cntlid_min larger than cntlid_max, the function incorrectly jumps to 'out_free_changed_ns_list' label instead of 'out_free_sqs', resulting in a memory leak of the ctrl->sqs allocation. The issue has been assigned a CVSS v3.1 base score of 5.3 MEDIUM (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) (NVD).

The vulnerability can lead to memory leaks in the kernel when creating NVMe controllers under specific conditions. This could potentially result in system resource exhaustion over time if repeatedly triggered (NVD).

The vulnerability requires the ability to create NVMe controllers with specific controller ID parameters. It can be triggered when cntlid_min is configured to be larger than cntlid_max in the subsystem configuration (Kernel Git).

The issue has been fixed by modifying the code to jump to the correct 'out_free_sqs' label instead of 'out_free_changed_ns_list' when cntlid_min is larger than cntlid_max. The fix has been implemented in the Linux kernel through a patch that properly handles the memory deallocation (Kernel Git).