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Message-Id: <20210112162829.775079-1-sdf@google.com>
Date: Tue, 12 Jan 2021 08:28:29 -0800
From: Stanislav Fomichev <sdf@...gle.com>
To: netdev@...r.kernel.org, bpf@...r.kernel.org
Cc: ast@...nel.org, daniel@...earbox.net,
Stanislav Fomichev <sdf@...gle.com>,
Martin KaFai Lau <kafai@...com>
Subject: [PATCH bpf v2] bpf: don't leak memory in bpf getsockopt when optlen
== 0
optlen == 0 indicates that the kernel should ignore BPF buffer
and use the original one from the user. We, however, forget
to free the temporary buffer that we've allocated for BPF.
Reported-by: Martin KaFai Lau <kafai@...com>
Fixes: d8fe449a9c51 ("bpf: Don't return EINVAL from {get,set}sockopt when optlen > PAGE_SIZE")
Signed-off-by: Stanislav Fomichev <sdf@...gle.com>
---
kernel/bpf/cgroup.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 6ec088a96302..96555a8a2c54 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1391,12 +1391,13 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
if (ctx.optlen != 0) {
*optlen = ctx.optlen;
*kernel_optval = ctx.optval;
+ /* export and don't free sockopt buf */
+ return 0;
}
}
out:
- if (ret)
- sockopt_free_buf(&ctx);
+ sockopt_free_buf(&ctx);
return ret;
}
--
2.30.0.284.gd98b1dd5eaa7-goog
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