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bpf: Fix the write filter
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Authored by markj on Oct 19 2021, 4:36 PM.

Details

Summary

A BPF descriptor only has an associated interface descriptor once it is
attached to an interface, e.g., with BIOCSETIF. Avoid dereferencing a
NULL pointer in filt_bpfwrite() if the BPF descriptor is not attached.

Fixes: ded77e0237a8 ("Allow the BPF to be select for write.")
Reported by: syzbot+ae45d5166afe15a5a21d@syzkaller.appspotmail.com

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Repository
R10 FreeBSD src repository
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Unit
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