Re: [PATCH 1/2] bpf: sockmap, fix uninitialized variable
From: John Fastabend <john.fastabend@gmail.com>
Date: 2018-05-17 17:27:46
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On 05/17/2018 07:08 AM, Gustavo A. R. Silva wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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. 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. Acked-by: John Fastabend <john.fastabend@gmail.com>