mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-01-08 05:24:32 -05:00
17c3df7078
the commit1ddc3229ad("skbuff: remove some unnecessary operation in skb_segment_list()") introduces an issue very similar to the one already fixed by commit53475c5dd8("net: fix use-after-free when UDP GRO with shared fraglist"). If the GSO skb goes though skb_clone() and pskb_expand_head() before entering skb_segment_list(), the latter will unshare the frag_list skbs and will release the old list. With the reverted commit in place, when skb_segment_list() completes, skb->next points to the just released list, and later on the kernel will hit UaF. Note that since commite0e3070a9b("udp: properly complete L4 GRO over UDP tunnel packet") the critical scenario can be reproduced also receiving UDP over vxlan traffic with: NIC (NETIF_F_GRO_FRAGLIST enabled) -> vxlan -> UDP sink Attaching a packet socket to the NIC will cause skb_clone() and the tunnel decapsulation will call pskb_expand_head(). Fixes:1ddc3229ad("skbuff: remove some unnecessary operation in skb_segment_list()") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>