netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: fix percpu counter block leak on error path when creating new netns Here is the stack where we allocate percpu counter block: +-< __alloc_percpu +-< xt_percpu_counter_alloc +-< find_check_entry # {arp,ip,ip6}_tables.c +-< translate_table And it can be leaked on this code path: +-> ip6t_register_table +-> translate_table # allocates percpu counter block +-> xt_register_table # fails there is no freeing of the counter block on xt_register_table fail. Note: xt_percpu_counter_free should be called to free it like we do in do_replace through cleanup_entry helper (or in __ip6t_unregister_table). Probability of hitting this error path is low AFAICS (xt_register_table can only return ENOMEM here, as it is not replacing anything, as we are creating new netns, and it is hard to imagine that all previous allocations succeeded and after that one in xt_register_table failed). But it's worth fixing even the rare leak.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
4.2