[PATCH 3.13.y-ckt 132/138] unix_diag: fix incorrect sign extension in unix_lookup_by_ino

From: Kamal Mostafa
Date: Wed Mar 09 2016 - 18:26:19 EST

3.13.11-ckt36 -stable review patch. If anyone has any objections, please let me know.


From: "Dmitry V. Levin" <ldv@xxxxxxxxxxxx>

commit b5f0549231ffb025337be5a625b0ff9f52b016f0 upstream.

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.

Fixes: 5d3cae8bc39d ("unix_diag: Dumping exact socket core")
Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
Acked-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
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 86fa0f3..27dd3dc 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -219,7 +219,7 @@ 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;