Linux kernel (openvswitch) vulnerabilities

In the Linux kernel, the openvswitch module has a use-after-free in CT limit teardown. The CT limit pointer was not removed from readers nor protected by an RCU grace period, so packet processing could dereference freed state when the network namespace is torn down. An unprivileged user can trigger this from a user and network namespace.

In the Linux kernel, openvswitch's queue_userspace_packet() calls skb_tx_error() on a packet it does not own and that is still being forwarded. This strips SKBFL_SHARED_FRAG from the live skb, causing a later local ESP-in-UDP delivery to decrypt in place over pages the sender does not own, enabling an unprivileged page-cache write (the "Fragnesia" primitive).

In the Linux kernel, the openvswitch module has a use-after-free vulnerability involving the flow->mask pointer during flow deletion (CMD_DEL). The mask pointer is freed via RCU, but ovs_flow_cmd_fill_info() uses it after the flow is removed from the table without first taking the RCU read lock. This creates a race condition and can cause a kernel crash (KASAN slab-use-after-free) in the window between removal and info filling.

A vulnerability has been identified in the Linux kernel that leads to self-deadlock when removing tunnel ports in openvswitch. The issue arises from improper management of RCU and RTNL contexts during device removal.