[PATCH] unix_diag: fix incorrect sign extension in unix_lookup_by_ino

[PATCH] unix_diag: fix incorrect sign extension in unix_lookup_by_ino

[Dmitry V. Levin]

The value passed by unix_diag_get_exact to unix_lookup_by_ino has type
__u32, but unix_lookup_by_ino's argument ino has type int, which is not
a problem yet.
However, when ino is compared with sock_i_ino return value of type
unsigned long, ino is sign extended to signed long, and this results
to incorrect comparison on 64-bit architectures for inode numbers
greater than INT_MAX.

This bug was found by strace test suite.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: <stable@vger.kernel.org>
---
 net/unix/diag.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/unix/diag.c b/net/unix/diag.c
index c512f64..4d96797 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -220,23 +220,23 @@ done:
 	return skb->len;
 }
 
-static struct sock *unix_lookup_by_ino(int ino)
+static struct sock *unix_lookup_by_ino(unsigned int ino)
 {
 	int i;
 	struct sock *sk;
 
 	spin_lock(&unix_table_lock);
 	for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) {
 		sk_for_each(sk, &unix_socket_table[i])
 			if (ino == sock_i_ino(sk)) {
 				sock_hold(sk);
 				spin_unlock(&unix_table_lock);
 
 				return sk;
 			}
 	}
 
 	spin_unlock(&unix_table_lock);
 	return NULL;
 }
 
-- 
ldv

Re: [PATCH] unix_diag: fix incorrect sign extension in unix_lookup_by_ino

[Cong Wang]

On Thu, Feb 18, 2016 at 5:27 PM, Dmitry V. Levin <ldv@altlinux.org> wrote:
> The value passed by unix_diag_get_exact to unix_lookup_by_ino has type
> __u32, but unix_lookup_by_ino's argument ino has type int, which is not
> a problem yet.
> However, when ino is compared with sock_i_ino return value of type
> unsigned long, ino is sign extended to signed long, and this results
> to incorrect comparison on 64-bit architectures for inode numbers
> greater than INT_MAX.
>
> This bug was found by strace test suite.
>
> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> Cc: <stable@vger.kernel.org>

Fixes: 5d3cae8bc39d ("unix_diag: Dumping exact socket core")
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>

Thanks.

Re: [PATCH] unix_diag: fix incorrect sign extension in unix_lookup_by_ino

[David Miller]

From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Fri, 19 Feb 2016 16:21:14 -0800

> On Thu, Feb 18, 2016 at 5:27 PM, Dmitry V. Levin <ldv@altlinux.org> wrote:
>> The value passed by unix_diag_get_exact to unix_lookup_by_ino has type
>> __u32, but unix_lookup_by_ino's argument ino has type int, which is not
>> a problem yet.
>> However, when ino is compared with sock_i_ino return value of type
>> unsigned long, ino is sign extended to signed long, and this results
>> to incorrect comparison on 64-bit architectures for inode numbers
>> greater than INT_MAX.
>>
>> This bug was found by strace test suite.
>>
>> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
>> Cc: <stable@vger.kernel.org>
> 
> Fixes: 5d3cae8bc39d ("unix_diag: Dumping exact socket core")
> Acked-by: Cong Wang <xiyou.wangcong@gmail.com>

Applied and queued up for -stable.