DEBIAN-CVE-2026-90049

In the Linux kernel, the following vulnerability has been resolved:  net: skbuff: don't skbtxerror() the source skb in skbzerocopy()  skbzerocopy() 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 nlaputfailure, and Open vSwitch does it in the flow-miss drop arm of ovsdpprocesspacket(), so nothing is lost by dropping it here.  On Open vSwitch's OVSACTIONATTRUSERSPACE path the skb is not freed on this error: doexecuteactions() ignores outputuserspace()'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.