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authorDmitry Safonov <dima@arista.com>2018-07-30 18:32:36 +0100
committerDavid S. Miller <davem@davemloft.net>2018-07-30 12:42:22 -0700
commit61f4b23769f0cc72ae62c9a81cf08f0397d40da8 (patch)
tree14625a2389a9357a44870604c3bff5f80ee3edcd
parentaf87f72e757a656d63c8410b1b0598b67d6a9ce3 (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.c6
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) {