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| author | Xin Long <lucien.xin@gmail.com> | 2017-09-06 11:53:29 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-09-06 21:22:54 -0700 |
| commit | f773608026ee1e75e2256e3ad625c222ff6f9305 (patch) | |
| tree | 3fcf22bd2c2e40f96e34df68dc69a1a2c707c1da | |
| parent | be82485fbcbb1cf11b13e7356231c72fdf21241c (diff) | |
| download | linux-f773608026ee1e75e2256e3ad625c222ff6f9305.tar.gz linux-f773608026ee1e75e2256e3ad625c222ff6f9305.tar.bz2 linux-f773608026ee1e75e2256e3ad625c222ff6f9305.zip | |
netlink: access nlk groups safely in netlink bind and getname
Now there is no lock protecting nlk ngroups/groups' accessing in
netlink bind and getname. It's safe from nlk groups' setting in
netlink_release, but not from netlink_realloc_groups called by
netlink_setsockopt.
netlink_lock_table is needed in both netlink bind and getname when
accessing nlk groups.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/netlink/af_netlink.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 94a61e602ee7..327807731b44 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -955,7 +955,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, struct net *net = sock_net(sk); struct netlink_sock *nlk = nlk_sk(sk); struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; - int err; + int err = 0; long unsigned int groups = nladdr->nl_groups; bool bound; @@ -983,6 +983,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, return -EINVAL; } + netlink_lock_table(); if (nlk->netlink_bind && groups) { int group; @@ -993,7 +994,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, if (!err) continue; netlink_undo_bind(group, groups, sk); - return err; + goto unlock; } } @@ -1006,12 +1007,13 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, netlink_autobind(sock); if (err) { netlink_undo_bind(nlk->ngroups, groups, sk); - return err; + goto unlock; } } if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) - return 0; + goto unlock; + netlink_unlock_table(); netlink_table_grab(); netlink_update_subscriptions(sk, nlk->subscriptions + @@ -1022,6 +1024,10 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, netlink_table_ungrab(); return 0; + +unlock: + netlink_unlock_table(); + return err; } static int netlink_connect(struct socket *sock, struct sockaddr *addr, @@ -1079,7 +1085,9 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr, nladdr->nl_groups = netlink_group_mask(nlk->dst_group); } else { nladdr->nl_pid = nlk->portid; + netlink_lock_table(); nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; + netlink_unlock_table(); } return 0; } |