CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's netfilter component, specifically in the ipset functionality, where improper handling of comment pointers during hash table resizing can lead to dereferencing stale pointers. This flaw could potentially allow an attacker to exploit the system by triggering a use-after-free condition, which may lead to crashes or arbitrary code execution. Organizations utilizing Linux systems with netfilter enabled should prioritize this issue to mitigate potential security risks.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: do not update comments from kernel-side hash adds mtype_resize() copies comment pointers with memcpy(), not the comment objects themselves. During the window after an entry has been copied but before the table swap and backlog replay, the old table is still published for packet-side updates while the replacement-table entry already holds the same ip_set_comment_rcu pointer. If xt_SET --add-set ... --exist hits that old entry in this window, mtype_add() calls ip_set_init_comment() even though packet-side adds carry no comment payload. That call frees the shared comment through the old entry, so the replacement-table entry now holds a stale pointer. When the queued add is replayed on the new table, mtype_add() calls ip_set_init_comment() again and strlen() dereferences the stale pointer. Fix this in mtype_add() by skipping ip_set_init_comment() when ext->target marks a packet-side add. Userspace adds still update comments, while packet-side adds can no longer free comment storage shared with a resize copy.