2017-12-21 15:58:07

by Vasyl Gomonovych

Subject: [PATCH] Smack: fix dereferenced before check

This patch fixes the warning reported by smatch:
security/smack/smack_lsm.c:2872 smack_socket_connect() warn:
variable dereferenced before check 'sock->sk' (see line 2869)

Signed-off-by: Vasyl Gomonovych <[email protected]>
---
security/smack/smack_lsm.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 14cc7940b36d..30f2c3d1c11c 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2866,12 +2866,16 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
#endif
#ifdef SMACK_IPV6_SECMARK_LABELING
struct smack_known *rsp;
- struct socket_smack *ssp = sock->sk->sk_security;
+ struct socket_smack *ssp;
#endif

if (sock->sk == NULL)
return 0;

+#ifdef SMACK_IPV6_SECMARK_LABELING
+ ssp = sock->sk->sk_security;
+#endif
+
switch (sock->sk->sk_family) {
case PF_INET:
if (addrlen < sizeof(struct sockaddr_in))
--
1.9.1

2017-12-21 17:57:18

by Serge E. Hallyn

Subject: Re: [PATCH] Smack: fix dereferenced before check

Quoting Vasyl Gomonovych ([email protected]):
> This patch fixes the warning reported by smatch:
> security/smack/smack_lsm.c:2872 smack_socket_connect() warn:
> variable dereferenced before check 'sock->sk' (see line 2869)
>
> Signed-off-by: Vasyl Gomonovych <[email protected]>

Looks obviously correct - thanks.

Acked-by: Serge Hallyn <[email protected]>

> ---
> security/smack/smack_lsm.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 14cc7940b36d..30f2c3d1c11c 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -2866,12 +2866,16 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
> #endif
> #ifdef SMACK_IPV6_SECMARK_LABELING
> struct smack_known *rsp;
> - struct socket_smack *ssp = sock->sk->sk_security;
> + struct socket_smack *ssp;
> #endif
>
> if (sock->sk == NULL)
> return 0;
>
> +#ifdef SMACK_IPV6_SECMARK_LABELING
> + ssp = sock->sk->sk_security;
> +#endif
> +
> switch (sock->sk->sk_family) {
> case PF_INET:
> if (addrlen < sizeof(struct sockaddr_in))
> --
> 1.9.1

2017-12-21 18:06:46

by Casey Schaufler

Subject: Re: [PATCH] Smack: fix dereferenced before check

On 12/21/2017 7:57 AM, Vasyl Gomonovych wrote:
> This patch fixes the warning reported by smatch:
> security/smack/smack_lsm.c:2872 smack_socket_connect() warn:
> variable dereferenced before check 'sock->sk' (see line 2869)
>
> Signed-off-by: Vasyl Gomonovych <[email protected]>

I will take this into the Smack tree. Thank you.

Acked-by: Casey Schaufler <[email protected]>

> ---
> security/smack/smack_lsm.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 14cc7940b36d..30f2c3d1c11c 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -2866,12 +2866,16 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
> #endif
> #ifdef SMACK_IPV6_SECMARK_LABELING
> struct smack_known *rsp;
> - struct socket_smack *ssp = sock->sk->sk_security;
> + struct socket_smack *ssp;
> #endif
>
> if (sock->sk == NULL)
> return 0;
>
> +#ifdef SMACK_IPV6_SECMARK_LABELING
> + ssp = sock->sk->sk_security;
> +#endif
> +
> switch (sock->sk->sk_family) {
> case PF_INET:
> if (addrlen < sizeof(struct sockaddr_in))