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author | Cong Wang <xiyou.wangcong@gmail.com> | 2018-10-11 11:15:13 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-04 14:51:52 +0100 |
commit | cc30c16a04cb82949ccf5403c95ebf7304feb229 (patch) | |
tree | 1bdc3351a66c84213abc9817f40738d86f28102f | |
parent | 23b5d05d91140ecc7ca3be1fa5eacd37a28d1019 (diff) | |
download | linux-stable-cc30c16a04cb82949ccf5403c95ebf7304feb229.tar.gz linux-stable-cc30c16a04cb82949ccf5403c95ebf7304feb229.tar.bz2 linux-stable-cc30c16a04cb82949ccf5403c95ebf7304feb229.zip |
llc: set SOCK_RCU_FREE in llc_sap_add_socket()
[ Upstream commit 5a8e7aea953bdb6d4da13aff6f1e7f9c62023499 ]
WHen an llc sock is added into the sk_laddr_hash of an llc_sap,
it is not marked with SOCK_RCU_FREE.
This causes that the sock could be freed while it is still being
read by __llc_lookup_established() with RCU read lock. sock is
refcounted, but with RCU read lock, nothing prevents the readers
getting a zero refcnt.
Fix it by setting SOCK_RCU_FREE in llc_sap_add_socket().
Reported-by: syzbot+11e05f04c15e03be5254@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | net/llc/llc_conn.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c index c0ac522b48a1..4ff89cb7c86f 100644 --- a/net/llc/llc_conn.c +++ b/net/llc/llc_conn.c @@ -734,6 +734,7 @@ void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk) llc_sk(sk)->sap = sap; spin_lock_bh(&sap->sk_lock); + sock_set_flag(sk, SOCK_RCU_FREE); sap->sk_count++; sk_nulls_add_node_rcu(sk, laddr_hb); hlist_add_head(&llc->dev_hash_node, dev_hb); |