bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
BugLink: https://bugs.launchpad.net/bugs/2089340
commit 5fe6e308abaea082c20fbf2aa5df8e14495622cf upstream.
If bpf_link_prime() fails, bpf_uprobe_multi_link_attach() goes to the
error_free label and frees the array of bpf_uprobe's without calling
bpf_uprobe_unregister().
This leaks bpf_uprobe->uprobe and worse, this frees bpf_uprobe->consumer
without removing it from the uprobe->consumers list.
Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Closes: https://lore.kernel.org/all/000000000000382d39061f59f2dd@google.com/
Reported-by: syzbot+f7a1c2c2711e4a780f19@syzkaller.appspotmail.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: syzbot+f7a1c2c2711e4a780f19@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240813152524.GA7292@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Portia Stephens <portia.stephens@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
This commit is contained in:
committed by
Mehmet Basaran
parent
dea8762062
commit
6b4050a054
@@ -3436,17 +3436,20 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
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uprobes[i].ref_ctr_offset,
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&uprobes[i].consumer);
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if (err) {
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bpf_uprobe_unregister(&path, uprobes, i);
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goto error_free;
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link->cnt = i;
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goto error_unregister;
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}
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}
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err = bpf_link_prime(&link->link, &link_primer);
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if (err)
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goto error_free;
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goto error_unregister;
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return bpf_link_settle(&link_primer);
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error_unregister:
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bpf_uprobe_unregister(&path, uprobes, link->cnt);
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error_free:
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kvfree(uprobes);
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kfree(link);
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