nf_tables_newset in net/netfilter/nf_tables_api.c in the Linux kernel before 5.12.13 allows local users to cause a denial of service (NULL pointer dereference and general protection fault) because of the missing initialization for nft_set_elem_expr_alloc. A local user can set a netfilter table expression in their own namespace.
Weakness
The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Linux_kernel |
Linux |
* |
5.12.13 (excluding) |
Potential Mitigations
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable’s type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.
References