Hi John,

On 05/17/2018 12:27 PM, John Fastabend wrote:
On 05/17/2018 07:08 AM, Gustavo A. R. Silva wrote:
There is a potential execution path in which variable err is
returned without being properly initialized previously.

Fix this by initializing variable err to 0.

Addresses-Coverity-ID: 1468964 ("Uninitialized scalar variable")
Fixes: e5cd3abcb31a ("bpf: sockmap, refactor sockmap routines to work
with hashmap")
Signed-off-by: Gustavo A. R. Silva <gust...@embeddedor.com>
  kernel/bpf/sockmap.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index c6de139..41b41fc 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -1713,7 +1713,7 @@ static int __sock_map_ctx_update_elem(struct bpf_map *map,
        struct smap_psock_map_entry *e = NULL;
        struct smap_psock *psock;
        bool new = false;
-       int err;
+       int err = 0;
/* 1. If sock map has BPF programs those will be inherited by the
         * sock being added. If the sock is already attached to BPF programs

Thanks for catching this and the quick fix. The path to hit this case
is to add a sock to a map (without a BPF program) where the sock already
has been added to another map. I don't have any tests for the case with
socks in multiple maps so I'll add some to the selftests so I remember
this case.

Glad to help. :)

The alternative fix would be to always 'return 0' at the end of the
function, but I think its probably better to init err here like above.

Yeah. I think initializing err is better in this case.

Acked-by: John Fastabend <john.fastab...@gmail.com>

Thank you

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