]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/commit
bpf/cpumap: make sure frame_size for build_skb is aligned if headroom isn't
authorJesper Dangaard Brouer <brouer@redhat.com>
Wed, 19 Dec 2018 16:00:23 +0000 (17:00 +0100)
committerDaniel Borkmann <daniel@iogearbox.net>
Thu, 20 Dec 2018 22:19:12 +0000 (23:19 +0100)
commit77ea5f4cbe2084db9ab021ba73fb7eadf1610884
treed9f8339df3ccd3a320f231c9ce662bc5a1db5ecf
parentd70f4ece9da12b7319a87d02d33a89353268c689
bpf/cpumap: make sure frame_size for build_skb is aligned if headroom isn't

The frame_size passed to build_skb must be aligned, else it is
possible that the embedded struct skb_shared_info gets unaligned.

For correctness make sure that xdpf->headroom in included in the
alignment. No upstream drivers can hit this, as all XDP drivers provide
an aligned headroom.  This was discovered when playing with implementing
XDP support for mvneta, which have a 2 bytes DSA header, and this
Marvell ARM64 platform didn't like doing atomic operations on an
unaligned skb_shinfo(skb)->dataref addresses.

Fixes: 1c601d829ab0 ("bpf: cpumap xdp_buff to skb conversion and allocation")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
kernel/bpf/cpumap.c