2019-06-04 12:12:47

by Young Xiao

Subject: [PATCH] rose: af_rose: avoid overflows in rose_setsockopt()

Check setsockopt arguments to avoid overflows and return -EINVAL for
too large arguments.

See commit 32288eb4d940 ("netrom: avoid overflows in nr_setsockopt()")
for details.

Signed-off-by: Young Xiao <[email protected]>
---
net/rose/af_rose.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index e274bc6..af831ee9 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -372,15 +372,15 @@ static int rose_setsockopt(struct socket *sock, int level, int optname,
{
struct sock *sk = sock->sk;
struct rose_sock *rose = rose_sk(sk);
- int opt;
+ unsigned long opt;

if (level != SOL_ROSE)
return -ENOPROTOOPT;

- if (optlen < sizeof(int))
+ if (optlen < sizeof(unsigned int))
return -EINVAL;

- if (get_user(opt, (int __user *)optval))
+ if (get_user(opt, (unsigned int __user *)optval))
return -EFAULT;

switch (optname) {
@@ -389,31 +389,31 @@ static int rose_setsockopt(struct socket *sock, int level, int optname,
return 0;

case ROSE_T1:
- if (opt < 1)
+ if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
rose->t1 = opt * HZ;
return 0;

case ROSE_T2:
- if (opt < 1)
+ if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
rose->t2 = opt * HZ;
return 0;

case ROSE_T3:
- if (opt < 1)
+ if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
rose->t3 = opt * HZ;
return 0;

case ROSE_HOLDBACK:
- if (opt < 1)
+ if (opt < 1 || opt > ULONG_MAX / HZ)
return -EINVAL;
rose->hb = opt * HZ;
return 0;

case ROSE_IDLE:
- if (opt < 0)
+ if (opt < 0 || opt > ULONG_MAX / HZ)
return -EINVAL;
rose->idle = opt * 60 * HZ;
return 0;
--
2.7.4

2019-06-04 13:16:41

by walter harms

Subject: Re: [PATCH] rose: af_rose: avoid overflows in rose_setsockopt()

Am 04.06.2019 14:11, schrieb Young Xiao:
> Check setsockopt arguments to avoid overflows and return -EINVAL for
> too large arguments.
>
> See commit 32288eb4d940 ("netrom: avoid overflows in nr_setsockopt()")
> for details.
>
> Signed-off-by: Young Xiao <[email protected]>
> ---
> net/rose/af_rose.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
> index e274bc6..af831ee9 100644
> --- a/net/rose/af_rose.c
> +++ b/net/rose/af_rose.c
> @@ -372,15 +372,15 @@ static int rose_setsockopt(struct socket *sock, int level, int optname,
> {
> struct sock *sk = sock->sk;
> struct rose_sock *rose = rose_sk(sk);
> - int opt;
> + unsigned long opt;
>
> if (level != SOL_ROSE)
> return -ENOPROTOOPT;
>
> - if (optlen < sizeof(int))
> + if (optlen < sizeof(unsigned int))
> return -EINVAL;

I do not thing that this will change much,
but maybe you would like to check against the sizeof (opt) here ?


>
> - if (get_user(opt, (int __user *)optval))
> + if (get_user(opt, (unsigned int __user *)optval))
> return -EFAULT;
>
> switch (optname) {
> @@ -389,31 +389,31 @@ static int rose_setsockopt(struct socket *sock, int level, int optname,
> return 0;
>


> case ROSE_T1:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->t1 = opt * HZ;
> return 0;
>
> case ROSE_T2:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->t2 = opt * HZ;
> return 0;
>
> case ROSE_T3:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->t3 = opt * HZ;
> return 0;
>
> case ROSE_HOLDBACK:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->hb = opt * HZ;
> return 0;

you can simplify this jungle by checking and calculation first
and then set the correct rose->XX

>
> case ROSE_IDLE:
> - if (opt < 0)
> + if (opt < 0 || opt > ULONG_MAX / HZ)
> return -EINVAL;

You made opt unsigned or ?

> rose->idle = opt * 60 * HZ;
> return 0;

my 2 cents,

re,
wh

2019-06-04 13:33:40

by Eric Dumazet

Subject: Re: [PATCH] rose: af_rose: avoid overflows in rose_setsockopt()

On 6/4/19 5:11 AM, Young Xiao wrote:
> Check setsockopt arguments to avoid overflows and return -EINVAL for
> too large arguments.
>
> See commit 32288eb4d940 ("netrom: avoid overflows in nr_setsockopt()")
> for details.
>
> Signed-off-by: Young Xiao <[email protected]>
> ---
> net/rose/af_rose.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
> index e274bc6..af831ee9 100644
> --- a/net/rose/af_rose.c
> +++ b/net/rose/af_rose.c
> @@ -372,15 +372,15 @@ static int rose_setsockopt(struct socket *sock, int level, int optname,
> {
> struct sock *sk = sock->sk;
> struct rose_sock *rose = rose_sk(sk);
> - int opt;
> + unsigned long opt;
>
> if (level != SOL_ROSE)
> return -ENOPROTOOPT;
>
> - if (optlen < sizeof(int))
> + if (optlen < sizeof(unsigned int))
> return -EINVAL;
>
> - if (get_user(opt, (int __user *)optval))
> + if (get_user(opt, (unsigned int __user *)optval))
> return -EFAULT;
>
> switch (optname) {
> @@ -389,31 +389,31 @@ static int rose_setsockopt(struct socket *sock, int level, int optname,
> return 0;
>
> case ROSE_T1:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->t1 = opt * HZ;
> return 0;
>
> case ROSE_T2:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->t2 = opt * HZ;
> return 0;
>
> case ROSE_T3:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->t3 = opt * HZ;
> return 0;
>
> case ROSE_HOLDBACK:
> - if (opt < 1)
> + if (opt < 1 || opt > ULONG_MAX / HZ)
> return -EINVAL;
> rose->hb = opt * HZ;
> return 0;
>
> case ROSE_IDLE:
> - if (opt < 0)
> + if (opt < 0 || opt > ULONG_MAX / HZ)

Buggy check.

> return -EINVAL;
> rose->idle = opt * 60 * HZ;
> return 0;
>