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authorCraig Gallek <kraig@google.com>2016-01-19 14:27:08 -0500
committerDavid S. Miller <davem@davemloft.net>2016-01-19 14:44:23 -0500
commitb4ace4f1ae07691b4f6ea9f3e92efbec083df058 (patch)
tree6845c5f7ff2e8994046ac9a41ea5d5ec00fd21ab /net
parentaf_iucv: Validate socket address length in iucv_sock_bind() (diff)
downloadlinux-dev-b4ace4f1ae07691b4f6ea9f3e92efbec083df058.tar.xz
linux-dev-b4ace4f1ae07691b4f6ea9f3e92efbec083df058.zip
soreuseport: fix NULL ptr dereference SO_REUSEPORT after bind
Marc Dionne discovered a NULL pointer dereference when setting SO_REUSEPORT on a socket after it is bound. This patch removes the assumption that at least one socket in the reuseport group is bound with the SO_REUSEPORT option before other bind calls occur. Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Reported-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: Craig Gallek <kraig@google.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock_reuseport.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index 1df98c557440..e92b759d906c 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -93,10 +93,17 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse)
* @sk2: Socket belonging to the existing reuseport group.
* May return ENOMEM and not add socket to group under memory pressure.
*/
-int reuseport_add_sock(struct sock *sk, const struct sock *sk2)
+int reuseport_add_sock(struct sock *sk, struct sock *sk2)
{
struct sock_reuseport *reuse;
+ if (!rcu_access_pointer(sk2->sk_reuseport_cb)) {
+ int err = reuseport_alloc(sk2);
+
+ if (err)
+ return err;
+ }
+
spin_lock_bh(&reuseport_lock);
reuse = rcu_dereference_protected(sk2->sk_reuseport_cb,
lockdep_is_held(&reuseport_lock)),