In the Linux kernel, the following vulnerability has been resolved:

xfrm: natkeepalive: avoid double free on send error

natkeepalivesend() frees the keepalive skb whenever the IPv4 or IPv6 send helper reports an error.

That cleanup is only correct before the skb is handed to the output path. Once ipbuildandsendpkt() or ip6xmit() takes ownership, the networking stack may already have consumed the skb before returning an error, so freeing it again is unsafe.

Handle the pre-handoff failure cases inside natkeepalivesendipv4() and natkeepalivesendipv6(), where the caller still owns the skb, and keep natkeepalivesend() responsible only for family dispatch and the unsupported-family cleanup path.

In the Linux kernel, the following vulnerability has been resolved:

net: bridge: stop fast-leave after deleting a port group

brmulticastleavegroup() iterates mp->ports with pp = &p->next in its fast-leave path. After brmulticastdelpg() removes p, continuing the loop advances pp through the deleted entry.

If multicast-to-unicast was enabled, the bridge can hold multiple port groups for the same port and group with different source MAC addresses. Once multicast-to-unicast is disabled, brportgroupequal() matches those entries by port only. A fast leave can then delete one entry and continue from its stale next pointer, leaving mp->ports pointing at a deleted port group.

Fast leave only needs to remove one matching port group. Break after brmulticastdelpg() so the loop stops before dereferencing the removed entry.

A use-after-free vulnerability was found in the Linux kernel's IPv6 FIB rule lookup path. In fib6rulesuppress(), when a route is suppressed and released via ip6rtputflags(), the res->rt6 pointer is not cleared. If no later rule supplies a replacement route, fib6rulelookup() returns the stale (freed) rt6info to its caller. The subsequent dstrelease() then operates on freed memory, hitting rcurefputslowpath(). A local attacker who can configure IPv6 routing/FIB rules could trigger this to cause a denial of service (kernel crash) or potentially escalate privileges.

In the Linux kernel, the following vulnerability has been resolved:

ipvs: do not propagate one-packet flag to synced conns

Synced connections can be created before their destination exists. When the destination is later added, ipvsbinddest() copies connection flags from the destination into cp->flags.

IPVSCONNFONEPACKET connections are not synced. If a synced connection inherits IPVSCONNFONEPACKET while it is already hashed, expiry can treat it as a one-packet connection and skip unlinking the existing conntab node, leaving stale hash nodes pointing at a freed struct ipvsconn.

Drop IPVSCONNFONEPACKET from destination flags when binding synced connections.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nfqueue: pin bridge device while NFQUEUE holds fake dst

The brnetfilter fake rtable is embedded in struct netbridge and is attached to bridged packets with skbdstsetnoref(). If such a packet is queued to NFQUEUE, nfqueue() upgrades that fake dst with skbdstforce().

At that point the queued skb can hold a real dst reference after bridge teardown has started. The problem is not that every bridged packet needs its own dst reference. The problem is that NFQUEUE can keep the bridge private fake dst alive after unregister begins.

Fix this by keeping the bridge fake dst model unchanged and pinning the bridge master device only while the packet sits in NFQUEUE. Record the bridge device in nfqueueentry when the queued skb carries a bridge fake dst, take a device reference for the queue lifetime, and drop it when the queue entry is freed.

Also make sure queued entries are reaped when that bridge device goes down, and drop the redundant nfbridgeinfoexists() test from the fake dst detection.

This keeps netdevpriv(br->dev) alive until verdict completion, so the embedded fake rtable and its metrics backing storage cannot be freed out from under dstrelease(). It also avoids the constant refcount bump and avoids using ipv4-specific dst helpers for IPv6 bridge traffic.