[PATCH] netrom: fix copying in user data in nr_setsockopt

[PATCH] netrom: fix copying in user data in nr_setsockopt

[Christoph Hellwig]

This code used to copy in an unsigned long worth of data before
the sockptr_t conversion, so restore that.

Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 net/netrom/af_netrom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 775064cdd0ee4..f1ba7dd3d253d 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -306,7 +306,7 @@ static int nr_setsockopt(struct socket *sock, int level, int optname,
 	if (optlen < sizeof(unsigned int))
 		return -EINVAL;
 
-	if (copy_from_sockptr(&opt, optval, sizeof(unsigned int)))
+	if (copy_from_sockptr(&opt, optval, sizeof(unsigned long)))
 		return -EFAULT;
 
 	switch (optname) {
-- 
2.30.2

Re: [PATCH] netrom: fix copying in user data in nr_setsockopt

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Tue,  4 Jan 2022 10:21:26 +0100 you wrote:
> This code used to copy in an unsigned long worth of data before
> the sockptr_t conversion, so restore that.
> 
> Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> [...]

Here is the summary with links:
  - netrom: fix copying in user data in nr_setsockopt
    https://git.kernel.org/netdev/net/c/3087a6f36ee0

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
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Re: [PATCH] netrom: fix copying in user data in nr_setsockopt

[Dan Carpenter]

On Tue, Jan 04, 2022 at 10:21:26AM +0100, Christoph Hellwig wrote:
> This code used to copy in an unsigned long worth of data before
> the sockptr_t conversion, so restore that.
> 
> Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  net/netrom/af_netrom.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
> index 775064cdd0ee4..f1ba7dd3d253d 100644
> --- a/net/netrom/af_netrom.c
> +++ b/net/netrom/af_netrom.c
> @@ -306,7 +306,7 @@ static int nr_setsockopt(struct socket *sock, int level, int optname,
>  	if (optlen < sizeof(unsigned int))
>  		return -EINVAL;
>  
> -	if (copy_from_sockptr(&opt, optval, sizeof(unsigned int)))
> +	if (copy_from_sockptr(&opt, optval, sizeof(unsigned long)))
>  		return -EFAULT;

No this isn't right.  In the original code, it copied an unsigned int.

	if (get_user(opt, (unsigned int __user *)optval))

The fix is to probably to change "opt" to an unsigned int.  I wonder if
I need to update all the integer overflow checks to from:

-	if (opt > ULONG_MAX / HZ)
+	if (opt > UINT_MAX / HZ)

...

Probably no one cares, right?  Ralf?

regards,
dan carpenter