The 'olr' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.
To fix the logic, check 'olr' as read from 'optlen',
where the types of relevant variables are (signed) int.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <[email protected]>
---
V2:
- reword the patch description
net/ipv4/ipmr.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 362229836510..b53c36c473a5 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1603,9 +1603,11 @@ int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
if (copy_from_sockptr(&olr, optlen, sizeof(int)))
return -EFAULT;
- olr = min_t(unsigned int, olr, sizeof(int));
if (olr < 0)
return -EINVAL;
+
+ olr = min_t(unsigned int, olr, sizeof(int));
+
if (copy_to_sockptr(optlen, &olr, sizeof(int)))
return -EFAULT;
if (copy_to_sockptr(optval, &val, olr))
--
2.39.2