CVE-2026-90049

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

net: skbuff: don't skbtxerror() the source skb in skb_zerocopy()

skb_zerocopy() copies frags from @from into @to. On an

skborphanfrags() failure it calls skbtxerror(@from), a destructive

operation on the source skb the copy helper does not own. That completes

@from's zerocopy uarg and clears SKBFLALLZEROCOPY, including the

SKBFLSHAREDFRAG page-ownership marker.

Both callers already report the failure on their own drop path.

nfnetlinkqueue does it at nlaput_failure, and Open vSwitch does it in

the flow-miss drop arm of ovsdpprocess_packet(), so nothing is lost by

dropping it here.

On Open vSwitch's OVSACTIONATTR_USERSPACE path the skb is not freed on

this error: doexecuteactions() ignores output_userspace()'s return

value and, unless the upcall was the last action, keeps forwarding the

same skb through the flow's remaining actions. The uarg is completed

while that skb is still in flight, telling the producer its buffers are

free, and SKBFLSHAREDFRAG is cleared on an skb the rest of the stack

still handles. That flag is what makes espinput() call skbcow_data()

instead of decrypting in place, so a later local ESP delivery can

decrypt over frags the skb does not own privately.

Leave error reporting to the callers.