diff options
| author | Dmitry Safonov <dima@arista.com> | 2018-07-30 18:32:36 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-09 12:17:59 +0200 |
| commit | 4d502572ea7da97550891c2b0bcd36fa4eb33401 (patch) | |
| tree | 31828bd913f8681c88a0485b9b04a013227958a6 | |
| parent | 4f08437d6cc3c243c868207a474496fb253c10ff (diff) | |
netlink: Don't shift with UB on nlk->ngroups
[ Upstream commit 61f4b23769f0cc72ae62c9a81cf08f0397d40da8 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 cbcc92ebe97a..26ff1c7bbcfa 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -985,7 +985,11 @@ 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) { |