[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 <l...@altlinux.org>
Cc: <sta...@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