Messages in this thread | | | Subject | Re: [PATCH 1/2] bpf: sockmap, fix uninitialized variable | From | "Gustavo A. R. Silva" <> | Date | Thu, 17 May 2018 13:12:43 -0500 |
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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 <gustavo@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.fastabend@gmail.com> >
Thank you -- Gustavo
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