| Message ID | 20230829054623.104293-2-alexhenrie24@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: ipv6/addrconf: ensure that temporary addresses' preferred lifetimes are in the valid range | expand |
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 94cec2075eee..c93a2b9a9172 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1368,7 +1368,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block) * idev->desync_factor if it's larger */ cnf_temp_preferred_lft = READ_ONCE(idev->cnf.temp_prefered_lft); - max_desync_factor = min_t(__u32, + max_desync_factor = min_t(long, idev->cnf.max_desync_factor, cnf_temp_preferred_lft - regen_advance);
The existing code incorrectly casted a negative value (the result of a subtraction) to an unsigned value without checking. For example, if /proc/sys/net/ipv6/conf/*/temp_prefered_lft was set to 1, the preferred lifetime would jump to 4 billion seconds. On my machine and network the shortest lifetime that avoided underflow was 3 seconds. Fixes: 76506a986dc3 (IPv6: fix DESYNC_FACTOR, 2016-10-13) Signed-off-by: Alex Henrie <alexhenrie24@gmail.com> --- net/ipv6/addrconf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)