CVE-2026-46319

Zwakheid

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: Only release RCU read lock after ct_ft When looking up a flow table in act_ct in tcf_ct_flow_table_get(), rhashtable_lookup_fast() internally opens and closes an RCU read critical section before returning ct_ft. The tcf_ct_flow_table_cleanup_work() can complete before refcount_inc_not_zero() is invoked on the returned ct_ft resulting in a UAF on the already freed ct_ft object. This vulnerability can lead to privilege escalation. Analysis from [email protected]: When initializing act_ct, tcf_ct_init() is called, which internally triggers tcf_ct_flow_table_get(). static int tcf_ct_flow_table_get(struct net *net, struct tcf_ct_params *params) { struct zones_ht_key key = { .net = net, .zone = params->zone }; struct tcf_ct_flow_table *ct_ft; int err = -ENOMEM; mutex_lock(&zones_mutex); ct_ft = rhashtable_lookup_fast(&zones_ht, &key, zones_params); // [1] if (ct_ft && refcount_inc_not_zero(&ct_ft->ref)) // [2] goto out_unlock; ... } static __always_inline void *rhashtable_lookup_fast( struct rhashtable *ht, const void *key, const struct rhashtable_params params) { void *obj; rcu_read_lock(

Getroffen producten

• linux linux_kernel

Bronnen

• https://git.kernel.org/stable/c/17dfb67cb399b660105d9a8c6100851c0d0cdc70
• https://git.kernel.org/stable/c/3e20e1b3058e0b94638e7b931c138e840e266724
• https://git.kernel.org/stable/c/4c727c6967a41b37efe0f26332ca9ec5b74785a3
• https://git.kernel.org/stable/c/67c9ecc9f2575273ed1323e312881fc98ac83d6d
• https://git.kernel.org/stable/c/a2e0c045c87aa252eb61412e67dd91f2c2b19f81
• https://git.kernel.org/stable/c/ece578ca61e572df96cfc80456357ebfae0b4b9e