From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 852C43FC2 for ; Mon, 28 Aug 2023 10:31:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 012CFC433C9; Mon, 28 Aug 2023 10:31:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218706; bh=brNCZzUPzw30BOGgpZXeQ2yW/TrGPcI1/vCREIR8x4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZBED2+/kzg0duC08fEvv4HBox/CXERrlbUYi+CWTlpA9sh9i2Phxv5h+7ww+31GJo XbY8/OiAywXgGelgi074LeYwXNfr1LzDFn9IO0eWg3spQc+c60Nevs/xBkISjj/R9b sMNl0ktYJmFecwxvG5RJf3IZprzaKAxI/ZW4EOYw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Oliver Hartkopp , Ziyang Xuan , Marc Kleine-Budde , Sasha Levin Subject: [PATCH 6.1 016/122] can: raw: fix receiver memory leak Date: Mon, 28 Aug 2023 12:12:11 +0200 Message-ID: <20230828101156.992105058@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101156.480754469@linuxfoundation.org> References: <20230828101156.480754469@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ziyang Xuan [ Upstream commit ee8b94c8510ce64afe0b87ef548d23e00915fb10 ] Got kmemleak errors with the following ltp can_filter testcase: for ((i=1; i<=100; i++)) do ./can_filter & sleep 0.1 done ============================================================== [<00000000db4a4943>] can_rx_register+0x147/0x360 [can] [<00000000a289549d>] raw_setsockopt+0x5ef/0x853 [can_raw] [<000000006d3d9ebd>] __sys_setsockopt+0x173/0x2c0 [<00000000407dbfec>] __x64_sys_setsockopt+0x61/0x70 [<00000000fd468496>] do_syscall_64+0x33/0x40 [<00000000b7e47d51>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 It's a bug in the concurrent scenario of unregister_netdevice_many() and raw_release() as following: cpu0 cpu1 unregister_netdevice_many(can_dev) unlist_netdevice(can_dev) // dev_get_by_index() return NULL after this net_set_todo(can_dev) raw_release(can_socket) dev = dev_get_by_index(, ro->ifindex); // dev == NULL if (dev) { // receivers in dev_rcv_lists not free because dev is NULL raw_disable_allfilters(, dev, ); dev_put(dev); } ... ro->bound = 0; ... call_netdevice_notifiers(NETDEV_UNREGISTER, ) raw_notify(, NETDEV_UNREGISTER, ) if (ro->bound) // invalid because ro->bound has been set 0 raw_disable_allfilters(, dev, ); // receivers in dev_rcv_lists will never be freed Add a net_device pointer member in struct raw_sock to record bound can_dev, and use rtnl_lock to serialize raw_socket members between raw_bind(), raw_release(), raw_setsockopt() and raw_notify(). Use ro->dev to decide whether to free receivers in dev_rcv_lists. Fixes: 8d0caedb7596 ("can: bcm/raw/isotp: use per module netdevice notifier") Reviewed-by: Oliver Hartkopp Acked-by: Oliver Hartkopp Signed-off-by: Ziyang Xuan Link: https://lore.kernel.org/all/20230711011737.1969582-1-william.xuanziyang@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- net/can/raw.c | 57 ++++++++++++++++++++++----------------------------- 1 file changed, 24 insertions(+), 33 deletions(-) diff --git a/net/can/raw.c b/net/can/raw.c index 4abab2c3011a3..1cd2c8748c26a 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -84,6 +84,7 @@ struct raw_sock { struct sock sk; int bound; int ifindex; + struct net_device *dev; struct list_head notifier; int loopback; int recv_own_msgs; @@ -277,7 +278,7 @@ static void raw_notify(struct raw_sock *ro, unsigned long msg, if (!net_eq(dev_net(dev), sock_net(sk))) return; - if (ro->ifindex != dev->ifindex) + if (ro->dev != dev) return; switch (msg) { @@ -292,6 +293,7 @@ static void raw_notify(struct raw_sock *ro, unsigned long msg, ro->ifindex = 0; ro->bound = 0; + ro->dev = NULL; ro->count = 0; release_sock(sk); @@ -337,6 +339,7 @@ static int raw_init(struct sock *sk) ro->bound = 0; ro->ifindex = 0; + ro->dev = NULL; /* set default filter to single entry dfilter */ ro->dfilter.can_id = 0; @@ -385,19 +388,13 @@ static int raw_release(struct socket *sock) lock_sock(sk); + rtnl_lock(); /* remove current filters & unregister */ if (ro->bound) { - if (ro->ifindex) { - struct net_device *dev; - - dev = dev_get_by_index(sock_net(sk), ro->ifindex); - if (dev) { - raw_disable_allfilters(dev_net(dev), dev, sk); - dev_put(dev); - } - } else { + if (ro->dev) + raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk); + else raw_disable_allfilters(sock_net(sk), NULL, sk); - } } if (ro->count > 1) @@ -405,8 +402,10 @@ static int raw_release(struct socket *sock) ro->ifindex = 0; ro->bound = 0; + ro->dev = NULL; ro->count = 0; free_percpu(ro->uniq); + rtnl_unlock(); sock_orphan(sk); sock->sk = NULL; @@ -422,6 +421,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) struct sockaddr_can *addr = (struct sockaddr_can *)uaddr; struct sock *sk = sock->sk; struct raw_sock *ro = raw_sk(sk); + struct net_device *dev = NULL; int ifindex; int err = 0; int notify_enetdown = 0; @@ -431,14 +431,13 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) if (addr->can_family != AF_CAN) return -EINVAL; + rtnl_lock(); lock_sock(sk); if (ro->bound && addr->can_ifindex == ro->ifindex) goto out; if (addr->can_ifindex) { - struct net_device *dev; - dev = dev_get_by_index(sock_net(sk), addr->can_ifindex); if (!dev) { err = -ENODEV; @@ -467,26 +466,20 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) if (!err) { if (ro->bound) { /* unregister old filters */ - if (ro->ifindex) { - struct net_device *dev; - - dev = dev_get_by_index(sock_net(sk), - ro->ifindex); - if (dev) { - raw_disable_allfilters(dev_net(dev), - dev, sk); - dev_put(dev); - } - } else { + if (ro->dev) + raw_disable_allfilters(dev_net(ro->dev), + ro->dev, sk); + else raw_disable_allfilters(sock_net(sk), NULL, sk); - } } ro->ifindex = ifindex; ro->bound = 1; + ro->dev = dev; } out: release_sock(sk); + rtnl_unlock(); if (notify_enetdown) { sk->sk_err = ENETDOWN; @@ -552,9 +545,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, rtnl_lock(); lock_sock(sk); - if (ro->bound && ro->ifindex) { - dev = dev_get_by_index(sock_net(sk), ro->ifindex); - if (!dev) { + dev = ro->dev; + if (ro->bound && dev) { + if (dev->reg_state != NETREG_REGISTERED) { if (count > 1) kfree(filter); err = -ENODEV; @@ -595,7 +588,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, ro->count = count; out_fil: - dev_put(dev); release_sock(sk); rtnl_unlock(); @@ -613,9 +605,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, rtnl_lock(); lock_sock(sk); - if (ro->bound && ro->ifindex) { - dev = dev_get_by_index(sock_net(sk), ro->ifindex); - if (!dev) { + dev = ro->dev; + if (ro->bound && dev) { + if (dev->reg_state != NETREG_REGISTERED) { err = -ENODEV; goto out_err; } @@ -639,7 +631,6 @@ static int raw_setsockopt(struct socket *sock, int level, int optname, ro->err_mask = err_mask; out_err: - dev_put(dev); release_sock(sk); rtnl_unlock(); -- 2.40.1