[PATCH] ipv6: fix signedness of tmp_prefered_lft underflow check
From: Jiri Bohac <hidden>
Date: 2016-10-18 15:02:02
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Commit 76506a986dc31394fd1f2741db037d29c7e57843 (IPv6: fix
DESYNC_FACTOR) introduced a buggy check for underflow of
tmp_prefered_lft. tmp_prefered_lft is unsigned, so the condition
is always false.
Signed-off-by: Jiri Bohac <redacted>
Reported-by: Julia Lawall <redacted>
Fixes: 76506a986dc3 ("IPv6: fix DESYNC_FACTOR")
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index cc7c26d..7a043a4 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c@@ -1248,7 +1248,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i tmp_prefered_lft = idev->cnf.temp_prefered_lft + age - idev->desync_factor; /* guard against underflow in case of concurrent updates to cnf */ - if (unlikely(tmp_prefered_lft < 0)) + if (unlikely((long)tmp_prefered_lft < 0)) tmp_prefered_lft = 0; tmp_prefered_lft = min_t(__u32, ifp->prefered_lft, tmp_prefered_lft); tmp_plen = ifp->prefix_len;