bpf: sockmap, fix smap_list_map_remove when psock is in many maps
If a hashmap is free'd with open socks it removes the reference to the hash entry from the psock. If that is the last reference to the psock then it will also be free'd by the reference counting logic. However the current logic that removes the hash reference from the list of references is broken. In smap_list_remove() we first check if the sockmap entry matches and then check if the hashmap entry matches. But, the sockmap entry sill always match because its NULL in this case which causes the first entry to be removed from the list. If this is always the "right" entry (because the user adds/removes entries in order) then everything is OK but otherwise a subsequent bpf_tcp_close() may reference a free'd object. To fix this create two list handlers one for sockmap and one for sockhash. Reported-by: syzbot+0ce137753c78f7b6acc1@syzkaller.appspotmail.com Fixes: 81110384 ("bpf: sockmap, add hash map support") Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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