diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2024-09-19 15:28:53 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-10-04 16:33:49 +0200 |
| commit | 7c1d782e5afbf7c50ba74ecc4ddc18a05d63e5ee (patch) | |
| tree | 89a82e639b35ec4fdcf6d81d4cf0b28dea343435 | |
| parent | a98fd7c6e7b2e5855cfc08cc77755f38a97c6158 (diff) | |
bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
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: 89ae89f53d20 ("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>
| -rw-r--r-- | kernel/trace/bpf_trace.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f0b7e9eb8172..433be6bc8b77 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3484,17 +3484,20 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr uprobes[i].ref_ctr_offset, &uprobes[i].consumer); if (err) { - bpf_uprobe_unregister(&path, uprobes, i); - goto error_free; + link->cnt = i; + goto error_unregister; } } err = bpf_link_prime(&link->link, &link_primer); if (err) - goto error_free; + goto error_unregister; return bpf_link_settle(&link_primer); +error_unregister: + bpf_uprobe_unregister(&path, uprobes, link->cnt); + error_free: kvfree(uprobes); kfree(link); |