diff options
| author | Dmitry Safonov <dima@arista.com> | 2018-07-30 18:32:36 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-07-30 12:42:22 -0700 |
| commit | 61f4b23769f0cc72ae62c9a81cf08f0397d40da8 (patch) | |
| tree | 14625a2389a9357a44870604c3bff5f80ee3edcd | |
| parent | af87f72e757a656d63c8410b1b0598b67d6a9ce3 (diff) | |
netlink: Don't shift with UB on nlk->ngroups
On i386 nlk->ngroups might be 32 or 0. Which leads to UB, resulting in
hang during boot.
Check for 0 ngroups and use (unsigned long long) as a type to shift.
Fixes: 7acf9d4237c4 ("netlink: Do not subscribe to non-existent groups").
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/netlink/af_netlink.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index ac805caed2e2..7d860a22e5fb 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1008,7 +1008,11 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, if (err) return err; } - groups &= (1UL << nlk->ngroups) - 1; + + if (nlk->ngroups == 0) + groups = 0; + else + groups &= (1ULL << nlk->ngroups) - 1; bound = nlk->bound; if (bound) { |