CVE-2021-47443: 
Linux Kernel vulnerability analysis and mitigation

In the Linux kernel, a memory leak vulnerability was discovered in the NFC (Near Field Communication) digital subsystem. The vulnerability, tracked as CVE-2021-47443, exists in the digital_tg_listen_mdaa() function where memory allocated for 'params' is not properly freed when digital_send_cmd() fails (Kernel Git).

The vulnerability occurs in the net/nfc/digital_core.c file within the digital_tg_listen_mdaa() function. When the function allocates memory for 'params' using kzalloc(), it fails to free this memory if the subsequent digital_send_cmd() call returns an error. This results in a memory leak condition. The issue was introduced in the commit that added target NFC-DEP support (Kernel Git).

The vulnerability can lead to memory leaks in the Linux kernel's NFC subsystem, potentially causing system resource exhaustion over time if the failing condition is triggered repeatedly (Kernel Git).

The vulnerability has been fixed by adding proper memory cleanup in case of failure. The fix involves checking the return value of digital_send_cmd() and freeing the 'params' memory if an error occurs. The patch has been merged into the Linux kernel (Kernel Git).