Re: [PATCH 1/2] bpf: sockmap, fix uninitialized variable
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
---
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
Thank you
--
Gustavo
Re: [PATCH 1/2] bpf: sockmap, fix uninitialized variable
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
> ---
> 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
