subsys/net/ip/ipv6mld.c:mldsend() read the packet interface via netpktiface(pkt) after netsenddata(pkt) returned successfully. Per the network stack's ownership contract (include/zephyr/net/netcore.h, and the explicit warning in subsys/net/ip/netcore.c:453-460 'do not use pkt after that call'), a successful send transfers ownership of the netpkt and the L2 driver frees it (e.g. ethernetsend() unrefs the packet on success, subsys/net/l2/ethernet/ethernet.c:790), returning it to its kmemslab.

The subsequent netpktiface(pkt) is therefore a read of a freed object; the recovered interface pointer is then dereferenced and incremented by the per-interface statistics path (netstats.h UPDATESTAT/SETSTAT) when CONFIGNETSTATISTICSPERINTERFACE is enabled. If the freed slot is concurrently reallocated, pkt->iface may read back as NULL (NULL-pointer dereference / crash) or as a stale/garbage pointer (stray increment write / memory corruption).

The path is reachable remotely on the local link without authentication: handlemldquery() (registered for NETICMPV6MLDQUERY) responds to a valid MLDv2 General Query (unspecified multicast address, hop limit 1) by calling sendmldreport() -> mldsend().

The result is a remotely triggerable denial of service of the networking stack, with a narrow possibility of memory corruption. The fix caches the interface in a local before sending and no longer touches the packet after netsenddata(). The IPv4/IGMP sibling (igmpsend) already used the corrected pattern.

The CONFIGUSERSPACE syscall verifier zvrfykpoll() in kernel/poll.c allocates a kernel-side copy of the user-supplied kpollevent[] via zthreadmalloc() and then validates each event's object handle. Before this fix, validation used KOOPS(KSYSCALLOBJ(...)) inline inside the loop, which kills the calling thread without freeing eventscopy.

A user thread can pass numevents >= 1 with a forged object handle to leak the allocation; because newly spawned user threads inherit the parent's resourcepool (kernel/thread.c), an attacker spawns sacrificial threads to repeat the leak until the shared kernel heap is exhausted. Once depleted, legitimate kernel allocations from that pool (kqueue alloc nodes, kmsgq buffers, future kpoll calls, etc.) fail, causing a system-level denial of service.

The fix replaces each inline KOOPS with a conditional goto oopsfree so the buffer is freed before the thread is killed. Affects Zephyr releases from v1.12.0 (when kpoll was first exposed to user mode) through v4.4.1.