bpf: Allow delete from sockmap/sockhash only if update is allowed
We have seen an influx of syzkaller reports where a BPF program attached to a tracepoint triggers a locking rule violation by performing a map_delete on a sockmap/sockhash. We don't intend to support this artificial use scenario. Extend the existing verifier allowed-program-type check for updating sockmap/sockhash to also cover deleting from a map. From now on only BPF programs which were previously allowed to update sockmap/sockhash can delete from these map types. Fixes: ff910599 ("bpf, sockmap: Prevent lock inversion deadlock in map delete elem") Reported-by:Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by:
<syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com> Signed-off-by:
Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Tested-by:
<syzbot+ec941d6e24f633a59172@syzkaller.appspotmail.com> Acked-by:
John Fastabend <john.fastabend@gmail.com> Closes: https://syzkaller.appspot.com/bug?extid=ec941d6e24f633a59172 Link: https://lore.kernel.org/bpf/20240527-sockmap-verify-deletes-v1-1-944b372f2101@cloudflare.com
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