Add NULL checks for `kmalloc` results

[atwardzik]

Task Description

Many kmalloc calls do not verify whether allocation succeeded. This may lead to undefined behaviour, crashes, or memory corruption when NULL pointers are dereferenced.

Goal

Ensure that every kmalloc invocation is followed by a NULL check.

On failure: return an appropriate error code from errno.h (e.g., -ENOMEM).

Affected Files

• src/kernel/resources.c
• src/kernel/tty.c
• src/kernel/proc.c
• src/fs/file.c
• src/fs/ramfs.c
• src/drivers/ethernet.c

[sumit-dr]

Hello @atwardzik,
Can you pls assign me this issue.
Thanks

[atwardzik]

Hi @sumit-dr,
sure! Thanks for picking this up! Please fork the repo and open a PR when ready.