In the Linux kernel, the following vulnerability has been resolved: tracing: Fix potential double free in create_var_ref() In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref().
https://git.kernel.org/stable/c/f8b383f83cb573152c577eca1ef101e89995b72a
https://git.kernel.org/stable/c/c27f744ceefadc7bbeb14233b6abc150ced617d2
https://git.kernel.org/stable/c/bd83ff3bbfb003832481c9bff999d12385f396ae
https://git.kernel.org/stable/c/99696a2592bca641eb88cc9a80c90e591afebd0f
https://git.kernel.org/stable/c/4fdfb15e08598711dbf50daf56a33965232daf0e
https://git.kernel.org/stable/c/37443b3508b8cce6832f8d25cb4550b2f7801f50
https://git.kernel.org/stable/c/058cb6d86b9789377216c936506b346aaa1eb581