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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, kernel test robot <lkp@intel.com>,
	Cong Wang <xiyou.wangcong@gmail.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 3.18 17/24] llc: fix NULL pointer deref for SOCK_ZAPPED
Date: Fri, 27 Apr 2018 15:57:52 +0200	[thread overview]
Message-ID: <20180427135632.293874446@linuxfoundation.org> (raw)
In-Reply-To: <20180427135631.584839868@linuxfoundation.org>

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Cong Wang <xiyou.wangcong@gmail.com>


[ Upstream commit 3a04ce7130a7e5dad4e78d45d50313747f8c830f ]

For SOCK_ZAPPED socket, we don't need to care about llc->sap,
so we should just skip these refcount functions in this case.

Fixes: f7e43672683b ("llc: hold llc_sap before release_sock()")
Reported-by: kernel test robot <lkp@intel.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>
---
 net/llc/af_llc.c |   21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -187,7 +187,6 @@ static int llc_ui_release(struct socket
 {
 	struct sock *sk = sock->sk;
 	struct llc_sock *llc;
-	struct llc_sap *sap;
 
 	if (unlikely(sk == NULL))
 		goto out;
@@ -198,15 +197,19 @@ static int llc_ui_release(struct socket
 		llc->laddr.lsap, llc->daddr.lsap);
 	if (!llc_send_disc(sk))
 		llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
-	sap = llc->sap;
-	/* Hold this for release_sock(), so that llc_backlog_rcv() could still
-	 * use it.
-	 */
-	llc_sap_hold(sap);
-	if (!sock_flag(sk, SOCK_ZAPPED))
+	if (!sock_flag(sk, SOCK_ZAPPED)) {
+		struct llc_sap *sap = llc->sap;
+
+		/* Hold this for release_sock(), so that llc_backlog_rcv()
+		 * could still use it.
+		 */
+		llc_sap_hold(sap);
 		llc_sap_remove_socket(llc->sap, sk);
-	release_sock(sk);
-	llc_sap_put(sap);
+		release_sock(sk);
+		llc_sap_put(sap);
+	} else {
+		release_sock(sk);
+	}
 	if (llc->dev)
 		dev_put(llc->dev);
 	sock_put(sk);

  parent reply	other threads:[~2018-04-27 13:57 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-27 13:57 [PATCH 3.18 00/24] 3.18.107-stable review Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 01/24] cifs: do not allow creating sockets except with SMB1 posix exensions Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 02/24] x86/tsc: Prevent 32bit truncation in calc_hpet_ref() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 03/24] ext4: fix deadlock between inline_data and ext4_expand_extra_isize_ea() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 04/24] ext4: bugfix for mmaped pages in mpage_release_unused_pages() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 05/24] ext4: dont update checksum of new initialized bitmaps Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 06/24] perf: Return proper values for user stack errors Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 07/24] mm/filemap.c: fix NULL pointer in page_cache_tree_insert() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 08/24] jbd2: fix use after free in kjournald2() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 09/24] bonding: do not set slave_dev npinfo before slave_enable_netpoll in bond_enslave Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 10/24] KEYS: DNS: limit the length of option strings Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 11/24] l2tp: check sockaddr length in pppol2tp_connect() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 12/24] tcp: dont read out-of-bounds opsize Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 13/24] team: avoid adding twice the same option to the event list Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 14/24] team: fix netconsole setup over team Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 15/24] pppoe: check sockaddr length in pppoe_connect() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 16/24] llc: hold llc_sap before release_sock() Greg Kroah-Hartman
2018-04-27 13:57 ` Greg Kroah-Hartman [this message]
2018-04-27 13:57 ` [PATCH 3.18 18/24] packet: fix bitfield update race Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 19/24] tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 20/24] net: af_packet: fix race in PACKET_{R|T}X_RING Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 21/24] llc: delete timers synchronously in llc_sk_free() Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 22/24] ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 23/24] scsi: mptsas: Disable WRITE SAME Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 3.18 24/24] cdrom: information leak in cdrom_ioctl_media_changed() Greg Kroah-Hartman
2018-04-27 16:00 ` [PATCH 3.18 00/24] 3.18.107-stable review Dede Dindin Qudsy
2018-04-28  5:51   ` Greg Kroah-Hartman
2018-04-28  6:40     ` Harsh Shandilya
2018-04-27 18:12 ` Shuah Khan
2018-04-28  5:02   ` Greg Kroah-Hartman
2018-04-27 19:03 ` kernelci.org bot
2018-04-27 19:41 ` Theodore Y. Ts'o
2018-04-28  4:35   ` Greg Kroah-Hartman
2018-04-27 21:33 ` Harsh Shandilya
2018-04-28  5:02   ` Greg Kroah-Hartman
2018-04-28 14:24 ` Guenter Roeck

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