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authorHannes Frederic Sowa <hannes@stressinduktion.org>2016-04-05 17:10:16 +0200
committerDavid S. Miller <davem@davemloft.net>2016-04-07 16:44:14 -0400
commit8ced425ee630c03beea06c1dfa35190bf8395d07 (patch)
tree24f93b5ab435e0bd4cada95b9f91df0a2e205186 /drivers/net/tun.c
parent1e1d04e678cf72442f57ce82803c7a407769135f (diff)
tun: use socket locks for sk_{attach,detatch}_filter
This reverts commit 5a5abb1fa3b05dd ("tun, bpf: fix suspicious RCU usage in tun_{attach, detach}_filter") and replaces it to use lock_sock around sk_{attach,detach}_filter. The checks inside filter.c are updated with lockdep_sock_is_held to check for proper socket locks. It keeps the code cleaner by ensuring that only one lock governs the socket filter instead of two independent locks. Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9abc36bf77ea..64bc143eddd9 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -622,8 +622,9 @@ static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filte
/* Re-attach the filter to persist device */
if (!skip_filter && (tun->filter_attached == true)) {
- err = __sk_attach_filter(&tun->fprog, tfile->socket.sk,
- lockdep_rtnl_is_held());
+ lock_sock(tfile->socket.sk);
+ err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
+ release_sock(tfile->socket.sk);
if (!err)
goto out;
}
@@ -1824,7 +1825,9 @@ static void tun_detach_filter(struct tun_struct *tun, int n)
for (i = 0; i < n; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
- __sk_detach_filter(tfile->socket.sk, lockdep_rtnl_is_held());
+ lock_sock(tfile->socket.sk);
+ sk_detach_filter(tfile->socket.sk);
+ release_sock(tfile->socket.sk);
}
tun->filter_attached = false;
@@ -1837,8 +1840,9 @@ static int tun_attach_filter(struct tun_struct *tun)
for (i = 0; i < tun->numqueues; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
- ret = __sk_attach_filter(&tun->fprog, tfile->socket.sk,
- lockdep_rtnl_is_held());
+ lock_sock(tfile->socket.sk);
+ ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
+ release_sock(tfile->socket.sk);
if (ret) {
tun_detach_filter(tun, i);
return ret;