From 44b3b7e068874040ca511fcd2a812b5fbcf44616 Mon Sep 17 00:00:00 2001 From: Richard Alpe Date: Mon, 14 Mar 2016 09:43:52 +0100 Subject: [PATCH 01/18] tipc: make sure IPv6 header fits in skb headroom commit 9bd160bfa27fa41927dbbce7ee0ea779700e09ef upstream. Expand headroom further in order to be able to fit the larger IPv6 header. Prior to this patch this caused a skb under panic for certain tipc packets when using IPv6 UDP bearer(s). Signed-off-by: Richard Alpe Acked-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Jon Maloy Signed-off-by: Greg Kroah-Hartman --- net/tipc/udp_media.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index 6af78c6276b4..4056798c54a5 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -52,7 +52,7 @@ /* IANA assigned UDP port */ #define UDP_PORT_DEFAULT 6118 -#define UDP_MIN_HEADROOM 28 +#define UDP_MIN_HEADROOM 48 static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = { [TIPC_NLA_UDP_UNSPEC] = {.type = NLA_UNSPEC}, From 3f31559043087b9cd45582c2eb12d7900cedc4ed Mon Sep 17 00:00:00 2001 From: Erik Hugne Date: Thu, 7 Apr 2016 10:40:43 -0400 Subject: [PATCH 02/18] tipc: make dist queue pernet commit 541726abe7daca64390c2ec34e6a203145f1686d upstream. Nametable updates received from the network that cannot be applied immediately are placed on a defer queue. This queue is global to the TIPC module, which might cause problems when using TIPC in containers. To prevent nametable updates from escaping into the wrong namespace, we make the queue pernet instead. Signed-off-by: Erik Hugne Signed-off-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/core.c | 1 + net/tipc/core.h | 3 +++ net/tipc/name_distr.c | 16 +++++++--------- 3 files changed, 11 insertions(+), 9 deletions(-) diff --git a/net/tipc/core.c b/net/tipc/core.c index 03a842870c52..e2bdb07a49a2 100644 --- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -69,6 +69,7 @@ static int __net_init tipc_init_net(struct net *net) if (err) goto out_nametbl; + INIT_LIST_HEAD(&tn->dist_queue); err = tipc_topsrv_start(net); if (err) goto out_subscr; diff --git a/net/tipc/core.h b/net/tipc/core.h index 18e95a8020cd..fe3b89e9cde4 100644 --- a/net/tipc/core.h +++ b/net/tipc/core.h @@ -103,6 +103,9 @@ struct tipc_net { spinlock_t nametbl_lock; struct name_table *nametbl; + /* Name dist queue */ + struct list_head dist_queue; + /* Topology subscription server */ struct tipc_server *topsrv; atomic_t subscription_count; diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c index f51c8bdbea1c..18f8152888f4 100644 --- a/net/tipc/name_distr.c +++ b/net/tipc/name_distr.c @@ -40,11 +40,6 @@ int sysctl_tipc_named_timeout __read_mostly = 2000; -/** - * struct tipc_dist_queue - queue holding deferred name table updates - */ -static struct list_head tipc_dist_queue = LIST_HEAD_INIT(tipc_dist_queue); - struct distr_queue_item { struct distr_item i; u32 dtype; @@ -340,9 +335,11 @@ static bool tipc_update_nametbl(struct net *net, struct distr_item *i, * tipc_named_add_backlog - add a failed name table update to the backlog * */ -static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node) +static void tipc_named_add_backlog(struct net *net, struct distr_item *i, + u32 type, u32 node) { struct distr_queue_item *e; + struct tipc_net *tn = net_generic(net, tipc_net_id); unsigned long now = get_jiffies_64(); e = kzalloc(sizeof(*e), GFP_ATOMIC); @@ -352,7 +349,7 @@ static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node) e->node = node; e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout); memcpy(e, i, sizeof(*i)); - list_add_tail(&e->next, &tipc_dist_queue); + list_add_tail(&e->next, &tn->dist_queue); } /** @@ -362,10 +359,11 @@ static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node) void tipc_named_process_backlog(struct net *net) { struct distr_queue_item *e, *tmp; + struct tipc_net *tn = net_generic(net, tipc_net_id); char addr[16]; unsigned long now = get_jiffies_64(); - list_for_each_entry_safe(e, tmp, &tipc_dist_queue, next) { + list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) { if (time_after(e->expires, now)) { if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype)) continue; @@ -405,7 +403,7 @@ void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq) node = msg_orignode(msg); while (count--) { if (!tipc_update_nametbl(net, item, node, mtype)) - tipc_named_add_backlog(item, mtype, node); + tipc_named_add_backlog(net, item, mtype, node); item++; } kfree_skb(skb); From 76ca3053f32c997472c325176c235a25170fc98b Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Mon, 2 May 2016 11:58:45 -0400 Subject: [PATCH 03/18] tipc: re-enable compensation for socket receive buffer double counting commit 7c8bcfb1255fe9d929c227d67bdcd84430fd200b upstream. In the refactoring commit d570d86497ee ("tipc: enqueue arrived buffers in socket in separate function") we did by accident replace the test if (sk->sk_backlog.len == 0) atomic_set(&tsk->dupl_rcvcnt, 0); with if (sk->sk_backlog.len) atomic_set(&tsk->dupl_rcvcnt, 0); This effectively disables the compensation we have for the double receive buffer accounting that occurs temporarily when buffers are moved from the backlog to the socket receive queue. Until now, this has gone unnoticed because of the large receive buffer limits we are applying, but becomes indispensable when we reduce this buffer limit later in this series. We now fix this by inverting the mentioned condition. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index b26b7a127773..d119291db852 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1755,7 +1755,7 @@ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk, /* Try backlog, compensating for double-counted bytes */ dcnt = &tipc_sk(sk)->dupl_rcvcnt; - if (sk->sk_backlog.len) + if (!sk->sk_backlog.len) atomic_set(dcnt, 0); lim = rcvbuf_limit(sk, skb) + atomic_read(dcnt); if (likely(!sk_add_backlog(sk, skb, lim))) From 2847736f563d0ac1f84ddad1e4877c0856bc1adb Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Wed, 8 Jun 2016 12:00:04 -0400 Subject: [PATCH 04/18] tipc: correct error in node fsm commit c4282ca76c5b81ed73ef4c5eb5c07ee397e51642 upstream. commit 88e8ac7000dc ("tipc: reduce transmission rate of reset messages when link is down") revealed a flaw in the node FSM, as defined in the log of commit 66996b6c47ed ("tipc: extend node FSM"). We see the following scenario: 1: Node B receives a RESET message from node A before its link endpoint is fully up, i.e., the node FSM is in state SELF_UP_PEER_COMING. This event will not change the node FSM state, but the (distinct) link FSM will move to state RESETTING. 2: As an effect of the previous event, the local endpoint on B will declare node A lost, and post the event SELF_DOWN to the its node FSM. This moves the FSM state to SELF_DOWN_PEER_LEAVING, meaning that no messages will be accepted from A until it receives another RESET message that confirms that A's endpoint has been reset. This is wasteful, since we know this as a fact already from the first received RESET, but worse is that the link instance's FSM has not wasted this information, but instead moved on to state ESTABLISHING, meaning that it repeatedly sends out ACTIVATE messages to the reset peer A. 3: Node A will receive one of the ACTIVATE messages, move its link FSM to state ESTABLISHED, and start repeatedly sending out STATE messages to node B. 4: Node B will consistently drop these messages, since it can only accept accept a RESET according to its node FSM. 5: After four lost STATE messages node A will reset its link and start repeatedly sending out RESET messages to B. 6: Because of the reduced send rate for RESET messages, it is very likely that A will receive an ACTIVATE (which is sent out at a much higher frequency) before it gets the chance to send a RESET, and A may hence quickly move back to state ESTABLISHED and continue sending out STATE messages, which will again be dropped by B. 7: GOTO 5. 8: After having repeated the cycle 5-7 a number of times, node A will by chance get in between with sending a RESET, and the situation is resolved. Unfortunately, we have seen that it may take a substantial amount of time before this vicious loop is broken, sometimes in the order of minutes. We correct this by making a small correction to the node FSM: When a node in state SELF_UP_PEER_COMING receives a SELF_DOWN event, it now moves directly back to state SELF_DOWN_PEER_DOWN, instead of as now SELF_DOWN_PEER_LEAVING. This is logically consistent, since we don't need to wait for RESET confirmation from of an endpoint that we alread know has been reset. It also means that node B in the scenario above will not be dropping incoming STATE messages, and the link can come up immediately. Finally, a symmetry comparison reveals that the FSM has a similar error when receiving the event PEER_DOWN in state PEER_UP_SELF_COMING. Instead of moving to PERR_DOWN_SELF_LEAVING, it should move directly to SELF_DOWN_PEER_DOWN. Although we have never seen any negative effect of this logical error, we choose fix this one, too. The node FSM looks as follows after those changes: +----------------------------------------+ | PEER_DOWN_EVT| | | +------------------------+----------------+ | |SELF_DOWN_EVT | | | | | | | | +-----------+ +-----------+ | | |NODE_ | |NODE_ | | | +----------|FAILINGOVER|<---------|SYNCHING |-----------+ | | |SELF_ +-----------+ FAILOVER_+-----------+ PEER_ | | | |DOWN_EVT | A BEGIN_EVT A | DOWN_EVT| | | | | | | | | | | | | | | | | | | | |FAILOVER_ |FAILOVER_ |SYNCH_ |SYNCH_ | | | | |END_EVT |BEGIN_EVT |BEGIN_EVT|END_EVT | | | | | | | | | | | | | | | | | | | | | +--------------+ | | | | | +-------->| SELF_UP_ |<-------+ | | | | +-----------------| PEER_UP |----------------+ | | | | |SELF_DOWN_EVT +--------------+ PEER_DOWN_EVT| | | | | | A A | | | | | | | | | | | | | | PEER_UP_EVT| |SELF_UP_EVT | | | | | | | | | | | V V V | | V V V +------------+ +-----------+ +-----------+ +------------+ |SELF_DOWN_ | |SELF_UP_ | |PEER_UP_ | |PEER_DOWN | |PEER_LEAVING| |PEER_COMING| |SELF_COMING| |SELF_LEAVING| +------------+ +-----------+ +-----------+ +------------+ | | A A | | | | | | | | | SELF_ | |SELF_ |PEER_ |PEER_ | | DOWN_EVT| |UP_EVT |UP_EVT |DOWN_EVT | | | | | | | | | | | | | | | +--------------+ | | |PEER_DOWN_EVT +--->| SELF_DOWN_ |<---+ SELF_DOWN_EVT| +------------------->| PEER_DOWN |<--------------------+ +--------------+ Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/node.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/tipc/node.c b/net/tipc/node.c index d468aad6163e..2df0b98d4a32 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -728,7 +728,7 @@ static void tipc_node_fsm_evt(struct tipc_node *n, int evt) state = SELF_UP_PEER_UP; break; case SELF_LOST_CONTACT_EVT: - state = SELF_DOWN_PEER_LEAVING; + state = SELF_DOWN_PEER_DOWN; break; case SELF_ESTABL_CONTACT_EVT: case PEER_LOST_CONTACT_EVT: @@ -747,7 +747,7 @@ static void tipc_node_fsm_evt(struct tipc_node *n, int evt) state = SELF_UP_PEER_UP; break; case PEER_LOST_CONTACT_EVT: - state = SELF_LEAVING_PEER_DOWN; + state = SELF_DOWN_PEER_DOWN; break; case SELF_LOST_CONTACT_EVT: case PEER_ESTABL_CONTACT_EVT: From 58f80ccf09c4fb8ae2819cd2c0583b885b6b5454 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 25 Jan 2016 22:54:56 +0100 Subject: [PATCH 05/18] tty: nozomi: avoid a harmless gcc warning commit a4f642a8a3c2838ad09fe8313d45db46600e1478 upstream. The nozomi wireless data driver has its own helper function to transfer data from a FIFO, doing an extra byte swap on big-endian architectures, presumably to bring the data back into byte-serial order after readw() or readl() perform their implicit byteswap. This helper function is used in the receive_data() function to first read the length into a 32-bit variable, which causes a compile-time warning: drivers/tty/nozomi.c: In function 'receive_data': drivers/tty/nozomi.c:857:9: warning: 'size' may be used uninitialized in this function [-Wmaybe-uninitialized] The problem is that gcc is unsure whether the data was actually read or not. We know that it is at this point, so we can replace it with a single readl() to shut up that warning. I am leaving the byteswap in there, to preserve the existing behavior, even though this seems fishy: Reading the length of the data into a cpu-endian variable should normally not use a second byteswap on big-endian systems, unless the hardware is aware of the CPU endianess. There appears to be a lot more confusion about endianess in this driver, so it probably has not worked on big-endian systems in a long time, if ever, and I have no way to test it. It's well possible that this driver has not been used by anyone in a while, the last patch that looks like it was tested on the hardware is from 2008. Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- drivers/tty/nozomi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c index 80f9de907563..5cc80b80c82b 100644 --- a/drivers/tty/nozomi.c +++ b/drivers/tty/nozomi.c @@ -823,7 +823,7 @@ static int receive_data(enum port_type index, struct nozomi *dc) struct tty_struct *tty = tty_port_tty_get(&port->port); int i, ret; - read_mem32((u32 *) &size, addr, 4); + size = __le32_to_cpu(readl(addr)); /* DBG1( "%d bytes port: %d", size, index); */ if (tty && test_bit(TTY_THROTTLED, &tty->flags)) { From 9a35bc2ae545b352966a107bf81d8fdcafe4d7bf Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 28 Jan 2016 22:58:28 +0100 Subject: [PATCH 06/18] hostap: avoid uninitialized variable use in hfa384x_get_rid commit 48dc5fb3ba53b20418de8514700f63d88c5de3a3 upstream. The driver reads a value from hfa384x_from_bap(), which may fail, and then assigns the value to a local variable. gcc detects that in in the failure case, the 'rlen' variable now contains uninitialized data: In file included from ../drivers/net/wireless/intersil/hostap/hostap_pci.c:220:0: drivers/net/wireless/intersil/hostap/hostap_hw.c: In function 'hfa384x_get_rid': drivers/net/wireless/intersil/hostap/hostap_hw.c:842:5: warning: 'rec' may be used uninitialized in this function [-Wmaybe-uninitialized] if (le16_to_cpu(rec.len) == 0) { This restructures the function as suggested by Russell King, to make it more readable and get more reliable error handling, by handling each failure mode using a goto. Signed-off-by: Arnd Bergmann Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/hostap/hostap_hw.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c index 6df3ee561d52..515aa3f993f3 100644 --- a/drivers/net/wireless/hostap/hostap_hw.c +++ b/drivers/net/wireless/hostap/hostap_hw.c @@ -836,25 +836,30 @@ static int hfa384x_get_rid(struct net_device *dev, u16 rid, void *buf, int len, spin_lock_bh(&local->baplock); res = hfa384x_setup_bap(dev, BAP0, rid, 0); - if (!res) - res = hfa384x_from_bap(dev, BAP0, &rec, sizeof(rec)); + if (res) + goto unlock; + + res = hfa384x_from_bap(dev, BAP0, &rec, sizeof(rec)); + if (res) + goto unlock; if (le16_to_cpu(rec.len) == 0) { /* RID not available */ res = -ENODATA; + goto unlock; } rlen = (le16_to_cpu(rec.len) - 1) * 2; - if (!res && exact_len && rlen != len) { + if (exact_len && rlen != len) { printk(KERN_DEBUG "%s: hfa384x_get_rid - RID len mismatch: " "rid=0x%04x, len=%d (expected %d)\n", dev->name, rid, rlen, len); res = -ENODATA; } - if (!res) - res = hfa384x_from_bap(dev, BAP0, buf, len); + res = hfa384x_from_bap(dev, BAP0, buf, len); +unlock: spin_unlock_bh(&local->baplock); mutex_unlock(&local->rid_bap_mtx); From d39cb4a597295c6fd5e01795a134f1e3c0914049 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 26 Jan 2016 13:08:10 -0500 Subject: [PATCH 07/18] gfs2: avoid uninitialized variable warning commit 67893f12e5374bbcaaffbc6e570acbc2714ea884 upstream. We get a bogus warning about a potential uninitialized variable use in gfs2, because the compiler does not figure out that we never use the leaf number if get_leaf_nr() returns an error: fs/gfs2/dir.c: In function 'get_first_leaf': fs/gfs2/dir.c:802:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized] fs/gfs2/dir.c: In function 'dir_split_leaf': fs/gfs2/dir.c:1021:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized] Changing the 'if (!error)' to 'if (!IS_ERR_VALUE(error))' is sufficient to let gcc understand that this is exactly the same condition as in IS_ERR() so it can optimize the code path enough to understand it. Signed-off-by: Arnd Bergmann Signed-off-by: Bob Peterson Signed-off-by: Greg Kroah-Hartman --- fs/gfs2/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c index ad8a5b757cc7..a443c6e54412 100644 --- a/fs/gfs2/dir.c +++ b/fs/gfs2/dir.c @@ -760,7 +760,7 @@ static int get_first_leaf(struct gfs2_inode *dip, u32 index, int error; error = get_leaf_nr(dip, index, &leaf_no); - if (!error) + if (!IS_ERR_VALUE(error)) error = get_leaf(dip, leaf_no, bh_out); return error; @@ -976,7 +976,7 @@ static int dir_split_leaf(struct inode *inode, const struct qstr *name) index = name->hash >> (32 - dip->i_depth); error = get_leaf_nr(dip, index, &leaf_no); - if (error) + if (IS_ERR_VALUE(error)) return error; /* Get the old leaf block */ From abc025d1e88a47c24a0f4411d851c1e9c3e0e87d Mon Sep 17 00:00:00 2001 From: Parthasarathy Bhuvaragan Date: Thu, 1 Sep 2016 16:22:16 +0200 Subject: [PATCH 08/18] tipc: fix random link resets while adding a second bearer commit d2f394dc4816b7bd1b44981d83509f18f19c53f0 upstream. In a dual bearer configuration, if the second tipc link becomes active while the first link still has pending nametable "bulk" updates, it randomly leads to reset of the second link. When a link is established, the function named_distribute(), fills the skb based on node mtu (allows room for TUNNEL_PROTOCOL) with NAME_DISTRIBUTOR message for each PUBLICATION. However, the function named_distribute() allocates the buffer by increasing the node mtu by INT_H_SIZE (to insert NAME_DISTRIBUTOR). This consumes the space allocated for TUNNEL_PROTOCOL. When establishing the second link, the link shall tunnel all the messages in the first link queue including the "bulk" update. As size of the NAME_DISTRIBUTOR messages while tunnelling, exceeds the link mtu the transmission fails (-EMSGSIZE). Thus, the synch point based on the message count of the tunnel packets is never reached leading to link timeout. In this commit, we adjust the size of name distributor message so that they can be tunnelled. Reviewed-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/name_distr.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c index 18f8152888f4..c4c151bc000c 100644 --- a/net/tipc/name_distr.c +++ b/net/tipc/name_distr.c @@ -62,6 +62,8 @@ static void publ_to_item(struct distr_item *i, struct publication *p) /** * named_prepare_buf - allocate & initialize a publication message + * + * The buffer returned is of size INT_H_SIZE + payload size */ static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size, u32 dest) @@ -166,9 +168,9 @@ static void named_distribute(struct net *net, struct sk_buff_head *list, struct publication *publ; struct sk_buff *skb = NULL; struct distr_item *item = NULL; - uint msg_dsz = (tipc_node_get_mtu(net, dnode, 0) / ITEM_SIZE) * - ITEM_SIZE; - uint msg_rem = msg_dsz; + u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0) - INT_H_SIZE) / + ITEM_SIZE) * ITEM_SIZE; + u32 msg_rem = msg_dsz; list_for_each_entry(publ, pls, local_list) { /* Prepare next buffer: */ From 59e0cd110fb9fb9aa97bb59c57789adb0e82da8d Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Fri, 17 Jun 2016 06:35:57 -0400 Subject: [PATCH 09/18] tipc: fix socket timer deadlock commit f1d048f24e66ba85d3dabf3d076cefa5f2b546b0 upstream. We sometimes observe a 'deadly embrace' type deadlock occurring between mutually connected sockets on the same node. This happens when the one-hour peer supervision timers happen to expire simultaneously in both sockets. The scenario is as follows: CPU 1: CPU 2: -------- -------- tipc_sk_timeout(sk1) tipc_sk_timeout(sk2) lock(sk1.slock) lock(sk2.slock) msg_create(probe) msg_create(probe) unlock(sk1.slock) unlock(sk2.slock) tipc_node_xmit_skb() tipc_node_xmit_skb() tipc_node_xmit() tipc_node_xmit() tipc_sk_rcv(sk2) tipc_sk_rcv(sk1) lock(sk2.slock) lock((sk1.slock) filter_rcv() filter_rcv() tipc_sk_proto_rcv() tipc_sk_proto_rcv() msg_create(probe_rsp) msg_create(probe_rsp) tipc_sk_respond() tipc_sk_respond() tipc_node_xmit_skb() tipc_node_xmit_skb() tipc_node_xmit() tipc_node_xmit() tipc_sk_rcv(sk1) tipc_sk_rcv(sk2) lock((sk1.slock) lock((sk2.slock) ===> DEADLOCK ===> DEADLOCK Further analysis reveals that there are three different locations in the socket code where tipc_sk_respond() is called within the context of the socket lock, with ensuing risk of similar deadlocks. We now solve this by passing a buffer queue along with all upcalls where sk_lock.slock may potentially be held. Response or rejected message buffers are accumulated into this queue instead of being sent out directly, and only sent once we know we are safely outside the slock context. Reported-by: GUNA Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/tipc/socket.c | 54 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 42 insertions(+), 12 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index d119291db852..65171f8e8c45 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -777,9 +777,11 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq, * @tsk: receiving socket * @skb: pointer to message buffer. */ -static void tipc_sk_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb) +static void tipc_sk_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb, + struct sk_buff_head *xmitq) { struct sock *sk = &tsk->sk; + u32 onode = tsk_own_node(tsk); struct tipc_msg *hdr = buf_msg(skb); int mtyp = msg_type(hdr); int conn_cong; @@ -792,7 +794,8 @@ static void tipc_sk_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb) if (mtyp == CONN_PROBE) { msg_set_type(hdr, CONN_PROBE_REPLY); - tipc_sk_respond(sk, skb, TIPC_OK); + if (tipc_msg_reverse(onode, &skb, TIPC_OK)) + __skb_queue_tail(xmitq, skb); return; } else if (mtyp == CONN_ACK) { conn_cong = tsk_conn_cong(tsk); @@ -1647,7 +1650,8 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf) * * Returns true if message was added to socket receive queue, otherwise false */ -static bool filter_rcv(struct sock *sk, struct sk_buff *skb) +static bool filter_rcv(struct sock *sk, struct sk_buff *skb, + struct sk_buff_head *xmitq) { struct socket *sock = sk->sk_socket; struct tipc_sock *tsk = tipc_sk(sk); @@ -1657,7 +1661,7 @@ static bool filter_rcv(struct sock *sk, struct sk_buff *skb) int usr = msg_user(hdr); if (unlikely(msg_user(hdr) == CONN_MANAGER)) { - tipc_sk_proto_rcv(tsk, skb); + tipc_sk_proto_rcv(tsk, skb, xmitq); return false; } @@ -1700,7 +1704,8 @@ static bool filter_rcv(struct sock *sk, struct sk_buff *skb) return true; reject: - tipc_sk_respond(sk, skb, err); + if (tipc_msg_reverse(tsk_own_node(tsk), &skb, err)) + __skb_queue_tail(xmitq, skb); return false; } @@ -1716,9 +1721,24 @@ reject: static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb) { unsigned int truesize = skb->truesize; + struct sk_buff_head xmitq; + u32 dnode, selector; - if (likely(filter_rcv(sk, skb))) + __skb_queue_head_init(&xmitq); + + if (likely(filter_rcv(sk, skb, &xmitq))) { atomic_add(truesize, &tipc_sk(sk)->dupl_rcvcnt); + return 0; + } + + if (skb_queue_empty(&xmitq)) + return 0; + + /* Send response/rejected message */ + skb = __skb_dequeue(&xmitq); + dnode = msg_destnode(buf_msg(skb)); + selector = msg_origport(buf_msg(skb)); + tipc_node_xmit_skb(sock_net(sk), skb, dnode, selector); return 0; } @@ -1732,12 +1752,13 @@ static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb) * Caller must hold socket lock */ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk, - u32 dport) + u32 dport, struct sk_buff_head *xmitq) { + unsigned long time_limit = jiffies + 2; + struct sk_buff *skb; unsigned int lim; atomic_t *dcnt; - struct sk_buff *skb; - unsigned long time_limit = jiffies + 2; + u32 onode; while (skb_queue_len(inputq)) { if (unlikely(time_after_eq(jiffies, time_limit))) @@ -1749,7 +1770,7 @@ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk, /* Add message directly to receive queue if possible */ if (!sock_owned_by_user(sk)) { - filter_rcv(sk, skb); + filter_rcv(sk, skb, xmitq); continue; } @@ -1762,7 +1783,9 @@ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk, continue; /* Overload => reject message back to sender */ - tipc_sk_respond(sk, skb, TIPC_ERR_OVERLOAD); + onode = tipc_own_addr(sock_net(sk)); + if (tipc_msg_reverse(onode, &skb, TIPC_ERR_OVERLOAD)) + __skb_queue_tail(xmitq, skb); break; } } @@ -1775,12 +1798,14 @@ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk, */ void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq) { + struct sk_buff_head xmitq; u32 dnode, dport = 0; int err; struct tipc_sock *tsk; struct sock *sk; struct sk_buff *skb; + __skb_queue_head_init(&xmitq); while (skb_queue_len(inputq)) { dport = tipc_skb_peek_port(inputq, dport); tsk = tipc_sk_lookup(net, dport); @@ -1788,9 +1813,14 @@ void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq) if (likely(tsk)) { sk = &tsk->sk; if (likely(spin_trylock_bh(&sk->sk_lock.slock))) { - tipc_sk_enqueue(inputq, sk, dport); + tipc_sk_enqueue(inputq, sk, dport, &xmitq); spin_unlock_bh(&sk->sk_lock.slock); } + /* Send pending response/rejected messages, if any */ + while ((skb = __skb_dequeue(&xmitq))) { + dnode = msg_destnode(buf_msg(skb)); + tipc_node_xmit_skb(net, skb, dnode, dport); + } sock_put(sk); continue; } From c50fd34e10897114a7be2120133bd7e0b4184024 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 28 Sep 2016 00:27:17 -0500 Subject: [PATCH 10/18] mnt: Add a per mount namespace limit on the number of mounts commit d29216842a85c7970c536108e093963f02714498 upstream. CAI Qian pointed out that the semantics of shared subtrees make it possible to create an exponentially increasing number of mounts in a mount namespace. mkdir /tmp/1 /tmp/2 mount --make-rshared / for i in $(seq 1 20) ; do mount --bind /tmp/1 /tmp/2 ; done Will create create 2^20 or 1048576 mounts, which is a practical problem as some people have managed to hit this by accident. As such CVE-2016-6213 was assigned. Ian Kent described the situation for autofs users as follows: > The number of mounts for direct mount maps is usually not very large because of > the way they are implemented, large direct mount maps can have performance > problems. There can be anywhere from a few (likely case a few hundred) to less > than 10000, plus mounts that have been triggered and not yet expired. > > Indirect mounts have one autofs mount at the root plus the number of mounts that > have been triggered and not yet expired. > > The number of autofs indirect map entries can range from a few to the common > case of several thousand and in rare cases up to between 30000 and 50000. I've > not heard of people with maps larger than 50000 entries. > > The larger the number of map entries the greater the possibility for a large > number of active mounts so it's not hard to expect cases of a 1000 or somewhat > more active mounts. So I am setting the default number of mounts allowed per mount namespace at 100,000. This is more than enough for any use case I know of, but small enough to quickly stop an exponential increase in mounts. Which should be perfect to catch misconfigurations and malfunctioning programs. For anyone who needs a higher limit this can be changed by writing to the new /proc/sys/fs/mount-max sysctl. Tested-by: CAI Qian Signed-off-by: "Eric W. Biederman" [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- Documentation/sysctl/fs.txt | 7 ++++++ fs/mount.h | 2 ++ fs/namespace.c | 50 ++++++++++++++++++++++++++++++++++++- fs/pnode.c | 2 +- fs/pnode.h | 1 + include/linux/mount.h | 2 ++ kernel/sysctl.c | 9 +++++++ 7 files changed, 71 insertions(+), 2 deletions(-) diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt index 302b5ed616a6..35e17f748ca7 100644 --- a/Documentation/sysctl/fs.txt +++ b/Documentation/sysctl/fs.txt @@ -265,6 +265,13 @@ aio-nr can grow to. ============================================================== +mount-max: + +This denotes the maximum number of mounts that may exist +in a mount namespace. + +============================================================== + 2. /proc/sys/fs/binfmt_misc ---------------------------------------------------------- diff --git a/fs/mount.h b/fs/mount.h index 3dc7dea5a357..13a4ebbbaa74 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -13,6 +13,8 @@ struct mnt_namespace { u64 seq; /* Sequence number to prevent loops */ wait_queue_head_t poll; u64 event; + unsigned int mounts; /* # of mounts in the namespace */ + unsigned int pending_mounts; }; struct mnt_pcp { diff --git a/fs/namespace.c b/fs/namespace.c index 7df3d406d3e0..f26d18d69712 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -27,6 +27,9 @@ #include "pnode.h" #include "internal.h" +/* Maximum number of mounts in a mount namespace */ +unsigned int sysctl_mount_max __read_mostly = 100000; + static unsigned int m_hash_mask __read_mostly; static unsigned int m_hash_shift __read_mostly; static unsigned int mp_hash_mask __read_mostly; @@ -925,6 +928,9 @@ static void commit_tree(struct mount *mnt) list_splice(&head, n->list.prev); + n->mounts += n->pending_mounts; + n->pending_mounts = 0; + __attach_mnt(mnt, parent); touch_mnt_namespace(n); } @@ -1445,11 +1451,16 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how) propagate_umount(&tmp_list); while (!list_empty(&tmp_list)) { + struct mnt_namespace *ns; bool disconnect; p = list_first_entry(&tmp_list, struct mount, mnt_list); list_del_init(&p->mnt_expire); list_del_init(&p->mnt_list); - __touch_mnt_namespace(p->mnt_ns); + ns = p->mnt_ns; + if (ns) { + ns->mounts--; + __touch_mnt_namespace(ns); + } p->mnt_ns = NULL; if (how & UMOUNT_SYNC) p->mnt.mnt_flags |= MNT_SYNC_UMOUNT; @@ -1850,6 +1861,28 @@ static int invent_group_ids(struct mount *mnt, bool recurse) return 0; } +int count_mounts(struct mnt_namespace *ns, struct mount *mnt) +{ + unsigned int max = READ_ONCE(sysctl_mount_max); + unsigned int mounts = 0, old, pending, sum; + struct mount *p; + + for (p = mnt; p; p = next_mnt(p, mnt)) + mounts++; + + old = ns->mounts; + pending = ns->pending_mounts; + sum = old + pending; + if ((old > sum) || + (pending > sum) || + (max < sum) || + (mounts > (max - sum))) + return -ENOSPC; + + ns->pending_mounts = pending + mounts; + return 0; +} + /* * @source_mnt : mount tree to be attached * @nd : place the mount tree @source_mnt is attached @@ -1919,6 +1952,7 @@ static int attach_recursive_mnt(struct mount *source_mnt, struct path *parent_path) { HLIST_HEAD(tree_list); + struct mnt_namespace *ns = dest_mnt->mnt_ns; struct mountpoint *smp; struct mount *child, *p; struct hlist_node *n; @@ -1931,6 +1965,13 @@ static int attach_recursive_mnt(struct mount *source_mnt, if (IS_ERR(smp)) return PTR_ERR(smp); + /* Is there space to add these mounts to the mount namespace? */ + if (!parent_path) { + err = count_mounts(ns, source_mnt); + if (err) + goto out; + } + if (IS_MNT_SHARED(dest_mnt)) { err = invent_group_ids(source_mnt, true); if (err) @@ -1970,11 +2011,14 @@ static int attach_recursive_mnt(struct mount *source_mnt, out_cleanup_ids: while (!hlist_empty(&tree_list)) { child = hlist_entry(tree_list.first, struct mount, mnt_hash); + child->mnt_parent->mnt_ns->pending_mounts = 0; umount_tree(child, UMOUNT_SYNC); } unlock_mount_hash(); cleanup_group_ids(source_mnt, NULL); out: + ns->pending_mounts = 0; + read_seqlock_excl(&mount_lock); put_mountpoint(smp); read_sequnlock_excl(&mount_lock); @@ -2804,6 +2848,8 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) init_waitqueue_head(&new_ns->poll); new_ns->event = 0; new_ns->user_ns = get_user_ns(user_ns); + new_ns->mounts = 0; + new_ns->pending_mounts = 0; return new_ns; } @@ -2853,6 +2899,7 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, q = new; while (p) { q->mnt_ns = new_ns; + new_ns->mounts++; if (new_fs) { if (&p->mnt == new_fs->root.mnt) { new_fs->root.mnt = mntget(&q->mnt); @@ -2891,6 +2938,7 @@ static struct mnt_namespace *create_mnt_ns(struct vfsmount *m) struct mount *mnt = real_mount(m); mnt->mnt_ns = new_ns; new_ns->root = mnt; + new_ns->mounts++; list_add(&mnt->mnt_list, &new_ns->list); } else { mntput(m); diff --git a/fs/pnode.c b/fs/pnode.c index b9f2af59b9a6..b394ca5307ec 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -259,7 +259,7 @@ static int propagate_one(struct mount *m) read_sequnlock_excl(&mount_lock); } hlist_add_head(&child->mnt_hash, list); - return 0; + return count_mounts(m->mnt_ns, child); } /* diff --git a/fs/pnode.h b/fs/pnode.h index 623f01772bec..dc87e65becd2 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -54,4 +54,5 @@ void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp, struct mount *copy_tree(struct mount *, struct dentry *, int); bool is_path_reachable(struct mount *, struct dentry *, const struct path *root); +int count_mounts(struct mnt_namespace *ns, struct mount *mnt); #endif /* _LINUX_PNODE_H */ diff --git a/include/linux/mount.h b/include/linux/mount.h index f822c3c11377..dc6cd800cd5d 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -95,4 +95,6 @@ extern void mark_mounts_for_expiry(struct list_head *mounts); extern dev_t name_to_dev_t(const char *name); +extern unsigned int sysctl_mount_max; + #endif /* _LINUX_MOUNT_H */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2f0d157258a2..300d64162aff 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -65,6 +65,7 @@ #include #include #include +#include #include #include @@ -1749,6 +1750,14 @@ static struct ctl_table fs_table[] = { .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, + { + .procname = "mount-max", + .data = &sysctl_mount_max, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, + }, { } }; From 0d9dac5d7cc31df50757f26bcbdfbcf47277a1b2 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 28 Jan 2016 09:22:44 -0200 Subject: [PATCH 11/18] xc2028: avoid use after free commit 8dfbcc4351a0b6d2f2d77f367552f48ffefafe18 upstream. If struct xc2028_config is passed without a firmware name, the following trouble may happen: [11009.907205] xc2028 5-0061: type set to XCeive xc2028/xc3028 tuner [11009.907491] ================================================================== [11009.907750] BUG: KASAN: use-after-free in strcmp+0x96/0xb0 at addr ffff8803bd78ab40 [11009.907992] Read of size 1 by task modprobe/28992 [11009.907994] ============================================================================= [11009.907997] BUG kmalloc-16 (Tainted: G W ): kasan: bad access detected [11009.907999] ----------------------------------------------------------------------------- [11009.908008] INFO: Allocated in xhci_urb_enqueue+0x214/0x14c0 [xhci_hcd] age=0 cpu=3 pid=28992 [11009.908012] ___slab_alloc+0x581/0x5b0 [11009.908014] __slab_alloc+0x51/0x90 [11009.908017] __kmalloc+0x27b/0x350 [11009.908022] xhci_urb_enqueue+0x214/0x14c0 [xhci_hcd] [11009.908026] usb_hcd_submit_urb+0x1e8/0x1c60 [11009.908029] usb_submit_urb+0xb0e/0x1200 [11009.908032] usb_serial_generic_write_start+0xb6/0x4c0 [11009.908035] usb_serial_generic_write+0x92/0xc0 [11009.908039] usb_console_write+0x38a/0x560 [11009.908045] call_console_drivers.constprop.14+0x1ee/0x2c0 [11009.908051] console_unlock+0x40d/0x900 [11009.908056] vprintk_emit+0x4b4/0x830 [11009.908061] vprintk_default+0x1f/0x30 [11009.908064] printk+0x99/0xb5 [11009.908067] kasan_report_error+0x10a/0x550 [11009.908070] __asan_report_load1_noabort+0x43/0x50 [11009.908074] INFO: Freed in xc2028_set_config+0x90/0x630 [tuner_xc2028] age=1 cpu=3 pid=28992 [11009.908077] __slab_free+0x2ec/0x460 [11009.908080] kfree+0x266/0x280 [11009.908083] xc2028_set_config+0x90/0x630 [tuner_xc2028] [11009.908086] xc2028_attach+0x310/0x8a0 [tuner_xc2028] [11009.908090] em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb] [11009.908094] em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb] [11009.908098] em28xx_dvb_init+0x81/0x8a [em28xx_dvb] [11009.908101] em28xx_register_extension+0xd9/0x190 [em28xx] [11009.908105] em28xx_dvb_register+0x10/0x1000 [em28xx_dvb] [11009.908108] do_one_initcall+0x141/0x300 [11009.908111] do_init_module+0x1d0/0x5ad [11009.908114] load_module+0x6666/0x9ba0 [11009.908117] SyS_finit_module+0x108/0x130 [11009.908120] entry_SYSCALL_64_fastpath+0x16/0x76 [11009.908123] INFO: Slab 0xffffea000ef5e280 objects=25 used=25 fp=0x (null) flags=0x2ffff8000004080 [11009.908126] INFO: Object 0xffff8803bd78ab40 @offset=2880 fp=0x0000000000000001 [11009.908130] Bytes b4 ffff8803bd78ab30: 01 00 00 00 2a 07 00 00 9d 28 00 00 01 00 00 00 ....*....(...... [11009.908133] Object ffff8803bd78ab40: 01 00 00 00 00 00 00 00 b0 1d c3 6a 00 88 ff ff ...........j.... [11009.908137] CPU: 3 PID: 28992 Comm: modprobe Tainted: G B W 4.5.0-rc1+ #43 [11009.908140] Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015 [11009.908142] ffff8803bd78a000 ffff8802c273f1b8 ffffffff81932007 ffff8803c6407a80 [11009.908148] ffff8802c273f1e8 ffffffff81556759 ffff8803c6407a80 ffffea000ef5e280 [11009.908153] ffff8803bd78ab40 dffffc0000000000 ffff8802c273f210 ffffffff8155ccb4 [11009.908158] Call Trace: [11009.908162] [] dump_stack+0x4b/0x64 [11009.908165] [] print_trailer+0xf9/0x150 [11009.908168] [] object_err+0x34/0x40 [11009.908171] [] kasan_report_error+0x230/0x550 [11009.908175] [] ? trace_hardirqs_off_caller+0x21/0x290 [11009.908179] [] ? kasan_unpoison_shadow+0x36/0x50 [11009.908182] [] __asan_report_load1_noabort+0x43/0x50 [11009.908185] [] ? __asan_register_globals+0x50/0xa0 [11009.908189] [] ? strcmp+0x96/0xb0 [11009.908192] [] strcmp+0x96/0xb0 [11009.908196] [] xc2028_set_config+0x15c/0x630 [tuner_xc2028] [11009.908200] [] xc2028_attach+0x310/0x8a0 [tuner_xc2028] [11009.908203] [] ? memset+0x28/0x30 [11009.908206] [] ? xc2028_set_config+0x630/0x630 [tuner_xc2028] [11009.908211] [] em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb] [11009.908215] [] ? em28xx_dvb_init.part.3+0x37c/0x5cf4 [em28xx_dvb] [11009.908219] [] ? hauppauge_hvr930c_init+0x487/0x487 [em28xx_dvb] [11009.908222] [] ? lgdt330x_attach+0x1cc/0x370 [lgdt330x] [11009.908226] [] ? i2c_read_demod_bytes.isra.2+0x210/0x210 [lgdt330x] [11009.908230] [] ? ref_module.part.15+0x10/0x10 [11009.908233] [] ? module_assert_mutex_or_preempt+0x80/0x80 [11009.908238] [] em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb] [11009.908242] [] ? em28xx_attach_xc3028.constprop.7+0x30d/0x30d [em28xx_dvb] [11009.908245] [] ? string+0x14d/0x1f0 [11009.908249] [] ? symbol_string+0xff/0x1a0 [11009.908253] [] ? uuid_string+0x6f0/0x6f0 [11009.908257] [] ? __kernel_text_address+0x7e/0xa0 [11009.908260] [] ? print_context_stack+0x7f/0xf0 [11009.908264] [] ? __module_address+0xb6/0x360 [11009.908268] [] ? is_ftrace_trampoline+0x99/0xe0 [11009.908271] [] ? __kernel_text_address+0x7e/0xa0 [11009.908275] [] ? debug_check_no_locks_freed+0x290/0x290 [11009.908278] [] ? dump_trace+0x11b/0x300 [11009.908282] [] ? em28xx_register_extension+0x23/0x190 [em28xx] [11009.908285] [] ? trace_hardirqs_off_caller+0x21/0x290 [11009.908289] [] ? trace_hardirqs_on_caller+0x16/0x590 [11009.908292] [] ? trace_hardirqs_on+0xd/0x10 [11009.908296] [] ? em28xx_register_extension+0x23/0x190 [em28xx] [11009.908299] [] ? mutex_trylock+0x400/0x400 [11009.908302] [] ? do_one_initcall+0x131/0x300 [11009.908306] [] ? call_rcu_sched+0x17/0x20 [11009.908309] [] ? put_object+0x48/0x70 [11009.908314] [] em28xx_dvb_init+0x81/0x8a [em28xx_dvb] [11009.908317] [] em28xx_register_extension+0xd9/0x190 [em28xx] [11009.908320] [] ? 0xffffffffa0150000 [11009.908324] [] em28xx_dvb_register+0x10/0x1000 [em28xx_dvb] [11009.908327] [] do_one_initcall+0x141/0x300 [11009.908330] [] ? try_to_run_init_process+0x40/0x40 [11009.908333] [] ? trace_hardirqs_on_caller+0x16/0x590 [11009.908337] [] ? kasan_unpoison_shadow+0x36/0x50 [11009.908340] [] ? kasan_unpoison_shadow+0x36/0x50 [11009.908343] [] ? kasan_unpoison_shadow+0x36/0x50 [11009.908346] [] ? __asan_register_globals+0x87/0xa0 [11009.908350] [] do_init_module+0x1d0/0x5ad [11009.908353] [] load_module+0x6666/0x9ba0 [11009.908356] [] ? symbol_put_addr+0x50/0x50 [11009.908361] [] ? em28xx_dvb_init.part.3+0x5989/0x5cf4 [em28xx_dvb] [11009.908366] [] ? module_frob_arch_sections+0x20/0x20 [11009.908369] [] ? open_exec+0x50/0x50 [11009.908374] [] ? ns_capable+0x5b/0xd0 [11009.908377] [] SyS_finit_module+0x108/0x130 [11009.908379] [] ? SyS_init_module+0x1f0/0x1f0 [11009.908383] [] ? lockdep_sys_exit_thunk+0x12/0x14 [11009.908394] [] entry_SYSCALL_64_fastpath+0x16/0x76 [11009.908396] Memory state around the buggy address: [11009.908398] ffff8803bd78aa00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908401] ffff8803bd78aa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908403] >ffff8803bd78ab00: fc fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc [11009.908405] ^ [11009.908407] ffff8803bd78ab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908409] ffff8803bd78ac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908411] ================================================================== In order to avoid it, let's set the cached value of the firmware name to NULL after freeing it. While here, return an error if the memory allocation fails. Signed-off-by: Mauro Carvalho Chehab Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/media/tuners/tuner-xc2028.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/tuners/tuner-xc2028.c b/drivers/media/tuners/tuner-xc2028.c index 4e941f00b600..082ff5608455 100644 --- a/drivers/media/tuners/tuner-xc2028.c +++ b/drivers/media/tuners/tuner-xc2028.c @@ -1403,11 +1403,12 @@ static int xc2028_set_config(struct dvb_frontend *fe, void *priv_cfg) * in order to avoid troubles during device release. */ kfree(priv->ctrl.fname); + priv->ctrl.fname = NULL; memcpy(&priv->ctrl, p, sizeof(priv->ctrl)); if (p->fname) { priv->ctrl.fname = kstrdup(p->fname, GFP_KERNEL); if (priv->ctrl.fname == NULL) - rc = -ENOMEM; + return -ENOMEM; } /* From 9540baadb61ba5ed08832bb2a4cbfd876db37ff4 Mon Sep 17 00:00:00 2001 From: Phil Turnbull Date: Tue, 2 Feb 2016 13:36:45 -0500 Subject: [PATCH 12/18] netfilter: nfnetlink: correctly validate length of batch messages commit c58d6c93680f28ac58984af61d0a7ebf4319c241 upstream. If nlh->nlmsg_len is zero then an infinite loop is triggered because 'skb_pull(skb, msglen);' pulls zero bytes. The calculation in nlmsg_len() underflows if 'nlh->nlmsg_len < NLMSG_HDRLEN' which bypasses the length validation and will later trigger an out-of-bound read. If the length validation does fail then the malformed batch message is copied back to userspace. However, we cannot do this because the nlh->nlmsg_len can be invalid. This leads to an out-of-bounds read in netlink_ack: [ 41.455421] ================================================================== [ 41.456431] BUG: KASAN: slab-out-of-bounds in memcpy+0x1d/0x40 at addr ffff880119e79340 [ 41.456431] Read of size 4294967280 by task a.out/987 [ 41.456431] ============================================================================= [ 41.456431] BUG kmalloc-512 (Not tainted): kasan: bad access detected [ 41.456431] ----------------------------------------------------------------------------- ... [ 41.456431] Bytes b4 ffff880119e79310: 00 00 00 00 d5 03 00 00 b0 fb fe ff 00 00 00 00 ................ [ 41.456431] Object ffff880119e79320: 20 00 00 00 10 00 05 00 00 00 00 00 00 00 00 00 ............... [ 41.456431] Object ffff880119e79330: 14 00 0a 00 01 03 fc 40 45 56 11 22 33 10 00 05 .......@EV."3... [ 41.456431] Object ffff880119e79340: f0 ff ff ff 88 99 aa bb 00 14 00 0a 00 06 fe fb ................ ^^ start of batch nlmsg with nlmsg_len=4294967280 ... [ 41.456431] Memory state around the buggy address: [ 41.456431] ffff880119e79400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 41.456431] ffff880119e79480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 41.456431] >ffff880119e79500: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc [ 41.456431] ^ [ 41.456431] ffff880119e79580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 41.456431] ffff880119e79600: fc fc fc fc fc fc fc fc fc fc fb fb fb fb fb fb [ 41.456431] ================================================================== Fix this with better validation of nlh->nlmsg_len and by setting NFNL_BATCH_FAILURE if any batch message fails length validation. CAP_NET_ADMIN is required to trigger the bugs. Fixes: 9ea2aa8b7dba ("netfilter: nfnetlink: validate nfnetlink header from batch") Signed-off-by: Phil Turnbull Signed-off-by: Pablo Neira Ayuso Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nfnetlink.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 77afe913d03d..9adedba78eea 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -326,10 +326,12 @@ replay: nlh = nlmsg_hdr(skb); err = 0; - if (nlmsg_len(nlh) < sizeof(struct nfgenmsg) || - skb->len < nlh->nlmsg_len) { - err = -EINVAL; - goto ack; + if (nlh->nlmsg_len < NLMSG_HDRLEN || + skb->len < nlh->nlmsg_len || + nlmsg_len(nlh) < sizeof(struct nfgenmsg)) { + nfnl_err_reset(&err_list); + status |= NFNL_BATCH_FAILURE; + goto done; } /* Only requests are handled by the kernel */ From 65d30f7545ffdddcf10a59f3e54b032c5ade2e9d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michal=20Kube=C4=8Dek?= Date: Fri, 2 Dec 2016 09:33:41 +0100 Subject: [PATCH 13/18] tipc: check minimum bearer MTU MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 3de81b758853f0b29c61e246679d20b513c4cfec upstream. Qian Zhang (张谦) reported a potential socket buffer overflow in tipc_msg_build() which is also known as CVE-2016-8632: due to insufficient checks, a buffer overflow can occur if MTU is too short for even tipc headers. As anyone can set device MTU in a user/net namespace, this issue can be abused by a regular user. As agreed in the discussion on Ben Hutchings' original patch, we should check the MTU at the moment a bearer is attached rather than for each processed packet. We also need to repeat the check when bearer MTU is adjusted to new device MTU. UDP case also needs a check to avoid overflow when calculating bearer MTU. Fixes: b97bf3fd8f6a ("[TIPC] Initial merge") Signed-off-by: Michal Kubecek Reported-by: Qian Zhang (张谦) Acked-by: Ying Xue Signed-off-by: David S. Miller [bwh: Backported to 4.4: - Adjust context - NETDEV_GOING_DOWN and NETDEV_CHANGEMTU cases in net notifier were combined] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- net/tipc/bearer.c | 13 +++++++++++-- net/tipc/bearer.h | 13 +++++++++++++ net/tipc/udp_media.c | 5 +++++ 3 files changed, 29 insertions(+), 2 deletions(-) diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 648f2a67f314..cb1381513c82 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -381,6 +381,10 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b, dev = dev_get_by_name(net, driver_name); if (!dev) return -ENODEV; + if (tipc_mtu_bad(dev, 0)) { + dev_put(dev); + return -EINVAL; + } /* Associate TIPC bearer with L2 bearer */ rcu_assign_pointer(b->media_ptr, dev); @@ -570,14 +574,19 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt, if (!b_ptr) return NOTIFY_DONE; - b_ptr->mtu = dev->mtu; - switch (evt) { case NETDEV_CHANGE: if (netif_carrier_ok(dev)) break; case NETDEV_GOING_DOWN: + tipc_reset_bearer(net, b_ptr); + break; case NETDEV_CHANGEMTU: + if (tipc_mtu_bad(dev, 0)) { + bearer_disable(net, b_ptr); + break; + } + b_ptr->mtu = dev->mtu; tipc_reset_bearer(net, b_ptr); break; case NETDEV_CHANGEADDR: diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index 552185bc4773..5f11e18b1fa1 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -39,6 +39,7 @@ #include "netlink.h" #include "core.h" +#include "msg.h" #include #define MAX_MEDIA 3 @@ -61,6 +62,9 @@ #define TIPC_MEDIA_TYPE_IB 2 #define TIPC_MEDIA_TYPE_UDP 3 +/* minimum bearer MTU */ +#define TIPC_MIN_BEARER_MTU (MAX_H_SIZE + INT_H_SIZE) + /** * struct tipc_node_map - set of node identifiers * @count: # of nodes in set @@ -226,4 +230,13 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id, void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id, struct sk_buff_head *xmitq); +/* check if device MTU is too low for tipc headers */ +static inline bool tipc_mtu_bad(struct net_device *dev, unsigned int reserve) +{ + if (dev->mtu >= TIPC_MIN_BEARER_MTU + reserve) + return false; + netdev_warn(dev, "MTU too low for tipc bearer\n"); + return true; +} + #endif /* _TIPC_BEARER_H */ diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index 4056798c54a5..78d6b78de29d 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -376,6 +376,11 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, udp_conf.local_ip.s_addr = htonl(INADDR_ANY); udp_conf.use_udp_checksums = false; ub->ifindex = dev->ifindex; + if (tipc_mtu_bad(dev, sizeof(struct iphdr) + + sizeof(struct udphdr))) { + err = -EINVAL; + goto err; + } b->mtu = dev->mtu - sizeof(struct iphdr) - sizeof(struct udphdr); #if IS_ENABLED(CONFIG_IPV6) From d23ef85b123d3dbd3ba8a3c5f0ef5e556feb635e Mon Sep 17 00:00:00 2001 From: Vlad Tsyrklevich Date: Wed, 12 Oct 2016 18:51:24 +0200 Subject: [PATCH 14/18] vfio/pci: Fix integer overflows, bitmask check commit 05692d7005a364add85c6e25a6c4447ce08f913a upstream. The VFIO_DEVICE_SET_IRQS ioctl did not sufficiently sanitize user-supplied integers, potentially allowing memory corruption. This patch adds appropriate integer overflow checks, checks the range bounds for VFIO_IRQ_SET_DATA_NONE, and also verifies that only single element in the VFIO_IRQ_SET_DATA_TYPE_MASK bitmask is set. VFIO_IRQ_SET_ACTION_TYPE_MASK is already correctly checked later in vfio_pci_set_irqs_ioctl(). Furthermore, a kzalloc is changed to a kcalloc because the use of a kzalloc with an integer multiplication allowed an integer overflow condition to be reached without this patch. kcalloc checks for overflow and should prevent a similar occurrence. Signed-off-by: Vlad Tsyrklevich Signed-off-by: Alex Williamson Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/vfio/pci/vfio_pci.c | 33 ++++++++++++++++++++----------- drivers/vfio/pci/vfio_pci_intrs.c | 2 +- 2 files changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 9982cb176ce8..830e2fd47642 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -562,8 +562,9 @@ static long vfio_pci_ioctl(void *device_data, } else if (cmd == VFIO_DEVICE_SET_IRQS) { struct vfio_irq_set hdr; + size_t size; u8 *data = NULL; - int ret = 0; + int max, ret = 0; minsz = offsetofend(struct vfio_irq_set, count); @@ -571,23 +572,31 @@ static long vfio_pci_ioctl(void *device_data, return -EFAULT; if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS || + hdr.count >= (U32_MAX - hdr.start) || hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK | VFIO_IRQ_SET_ACTION_TYPE_MASK)) return -EINVAL; - if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) { - size_t size; - int max = vfio_pci_get_irq_count(vdev, hdr.index); + max = vfio_pci_get_irq_count(vdev, hdr.index); + if (hdr.start >= max || hdr.start + hdr.count > max) + return -EINVAL; - if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL) - size = sizeof(uint8_t); - else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD) - size = sizeof(int32_t); - else - return -EINVAL; + switch (hdr.flags & VFIO_IRQ_SET_DATA_TYPE_MASK) { + case VFIO_IRQ_SET_DATA_NONE: + size = 0; + break; + case VFIO_IRQ_SET_DATA_BOOL: + size = sizeof(uint8_t); + break; + case VFIO_IRQ_SET_DATA_EVENTFD: + size = sizeof(int32_t); + break; + default: + return -EINVAL; + } - if (hdr.argsz - minsz < hdr.count * size || - hdr.start >= max || hdr.start + hdr.count > max) + if (size) { + if (hdr.argsz - minsz < hdr.count * size) return -EINVAL; data = memdup_user((void __user *)(arg + minsz), diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index 20e9a86d2dcf..5c8f767b6368 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -255,7 +255,7 @@ static int vfio_msi_enable(struct vfio_pci_device *vdev, int nvec, bool msix) if (!is_irq_none(vdev)) return -EINVAL; - vdev->ctx = kzalloc(nvec * sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL); + vdev->ctx = kcalloc(nvec, sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL); if (!vdev->ctx) return -ENOMEM; From a7544fdd1626b65db635022c9d36007bb32dd6d8 Mon Sep 17 00:00:00 2001 From: EunTaik Lee Date: Wed, 24 Feb 2016 04:38:06 +0000 Subject: [PATCH 15/18] staging/android/ion : fix a race condition in the ion driver commit 9590232bb4f4cc824f3425a6e1349afbe6d6d2b7 upstream. There is a use-after-free problem in the ion driver. This is caused by a race condition in the ion_ioctl() function. A handle has ref count of 1 and two tasks on different cpus calls ION_IOC_FREE simultaneously. cpu 0 cpu 1 ------------------------------------------------------- ion_handle_get_by_id() (ref == 2) ion_handle_get_by_id() (ref == 3) ion_free() (ref == 2) ion_handle_put() (ref == 1) ion_free() (ref == 0 so ion_handle_destroy() is called and the handle is freed.) ion_handle_put() is called and it decreases the slub's next free pointer The problem is detected as an unaligned access in the spin lock functions since it uses load exclusive instruction. In some cases it corrupts the slub's free pointer which causes a mis-aligned access to the next free pointer.(kmalloc returns a pointer like ffffc0745b4580aa). And it causes lots of other hard-to-debug problems. This symptom is caused since the first member in the ion_handle structure is the reference count and the ion driver decrements the reference after it has been freed. To fix this problem client->lock mutex is extended to protect all the codes that uses the handle. Signed-off-by: Eun Taik Lee Reviewed-by: Laura Abbott Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman index 7ff2a7ec871f..33b390e7ea31 --- drivers/staging/android/ion/ion.c | 59 +++++++++++++++++++++++-------- 1 file changed, 44 insertions(+), 15 deletions(-) diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index df560216d702..374f840f31a4 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -387,13 +387,22 @@ static void ion_handle_get(struct ion_handle *handle) kref_get(&handle->ref); } -static int ion_handle_put(struct ion_handle *handle) +static int ion_handle_put_nolock(struct ion_handle *handle) +{ + int ret; + + ret = kref_put(&handle->ref, ion_handle_destroy); + + return ret; +} + +int ion_handle_put(struct ion_handle *handle) { struct ion_client *client = handle->client; int ret; mutex_lock(&client->lock); - ret = kref_put(&handle->ref, ion_handle_destroy); + ret = ion_handle_put_nolock(handle); mutex_unlock(&client->lock); return ret; @@ -417,18 +426,28 @@ static struct ion_handle *ion_handle_lookup(struct ion_client *client, return ERR_PTR(-EINVAL); } -static struct ion_handle *ion_handle_get_by_id(struct ion_client *client, +static struct ion_handle *ion_handle_get_by_id_nolock(struct ion_client *client, + int id) +{ + struct ion_handle *handle; + + handle = idr_find(&client->idr, id); + if (handle) + ion_handle_get(handle); + + return handle ? handle : ERR_PTR(-EINVAL); +} + +struct ion_handle *ion_handle_get_by_id(struct ion_client *client, int id) { struct ion_handle *handle; mutex_lock(&client->lock); - handle = idr_find(&client->idr, id); - if (handle) - ion_handle_get(handle); + handle = ion_handle_get_by_id_nolock(client, id); mutex_unlock(&client->lock); - return handle ? handle : ERR_PTR(-EINVAL); + return handle; } static bool ion_handle_validate(struct ion_client *client, @@ -532,22 +551,28 @@ struct ion_handle *ion_alloc(struct ion_client *client, size_t len, } EXPORT_SYMBOL(ion_alloc); -void ion_free(struct ion_client *client, struct ion_handle *handle) +static void ion_free_nolock(struct ion_client *client, struct ion_handle *handle) { bool valid_handle; BUG_ON(client != handle->client); - mutex_lock(&client->lock); valid_handle = ion_handle_validate(client, handle); if (!valid_handle) { WARN(1, "%s: invalid handle passed to free.\n", __func__); - mutex_unlock(&client->lock); return; } + ion_handle_put_nolock(handle); +} + +void ion_free(struct ion_client *client, struct ion_handle *handle) +{ + BUG_ON(client != handle->client); + + mutex_lock(&client->lock); + ion_free_nolock(client, handle); mutex_unlock(&client->lock); - ion_handle_put(handle); } EXPORT_SYMBOL(ion_free); @@ -1283,11 +1308,15 @@ static long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct ion_handle *handle; - handle = ion_handle_get_by_id(client, data.handle.handle); - if (IS_ERR(handle)) + mutex_lock(&client->lock); + handle = ion_handle_get_by_id_nolock(client, data.handle.handle); + if (IS_ERR(handle)) { + mutex_unlock(&client->lock); return PTR_ERR(handle); - ion_free(client, handle); - ion_handle_put(handle); + } + ion_free_nolock(client, handle); + ion_handle_put_nolock(handle); + mutex_unlock(&client->lock); break; } case ION_IOC_SHARE: From b7f47c794bc45eae975bf2a52a4463333111bb2a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 24 Mar 2017 19:36:13 -0700 Subject: [PATCH 16/18] ping: implement proper locking commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream. We got a report of yet another bug in ping http://www.openwall.com/lists/oss-security/2017/03/24/6 ->disconnect() is not called with socket lock held. Fix this by acquiring ping rwlock earlier. Thanks to Daniel, Alexander and Andrey for letting us know this problem. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet Reported-by: Daniel Jiang Reported-by: Solar Designer Reported-by: Andrey Konovalov Signed-off-by: David S. Miller Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ping.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 3a00512addbc..37a3b05d175c 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -154,17 +154,18 @@ void ping_hash(struct sock *sk) void ping_unhash(struct sock *sk) { struct inet_sock *isk = inet_sk(sk); + pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); + write_lock_bh(&ping_table.lock); if (sk_hashed(sk)) { - write_lock_bh(&ping_table.lock); hlist_nulls_del(&sk->sk_nulls_node); sk_nulls_node_init(&sk->sk_nulls_node); sock_put(sk); isk->inet_num = 0; isk->inet_sport = 0; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); - write_unlock_bh(&ping_table.lock); } + write_unlock_bh(&ping_table.lock); } EXPORT_SYMBOL_GPL(ping_unhash); From 416bd4a366f3b4cd3f6a3246f91bd9f425891547 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 11 Jan 2017 21:09:50 +0100 Subject: [PATCH 17/18] perf/core: Fix concurrent sys_perf_event_open() vs. 'move_group' race commit 321027c1fe77f892f4ea07846aeae08cefbbb290 upstream. Di Shen reported a race between two concurrent sys_perf_event_open() calls where both try and move the same pre-existing software group into a hardware context. The problem is exactly that described in commit: f63a8daa5812 ("perf: Fix event->ctx locking") ... where, while we wait for a ctx->mutex acquisition, the event->ctx relation can have changed under us. That very same commit failed to recognise sys_perf_event_context() as an external access vector to the events and thereby didn't apply the established locking rules correctly. So while one sys_perf_event_open() call is stuck waiting on mutex_lock_double(), the other (which owns said locks) moves the group about. So by the time the former sys_perf_event_open() acquires the locks, the context we've acquired is stale (and possibly dead). Apply the established locking rules as per perf_event_ctx_lock_nested() to the mutex_lock_double() for the 'move_group' case. This obviously means we need to validate state after we acquire the locks. Reported-by: Di Shen (Keen Lab) Tested-by: John Dias Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Kees Cook Cc: Linus Torvalds Cc: Min Chong Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Fixes: f63a8daa5812 ("perf: Fix event->ctx locking") Link: http://lkml.kernel.org/r/20170106131444.GZ3174@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar [bwh: Backported to 4.4: - Test perf_event::group_flags instead of group_caps - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 57 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 53 insertions(+), 4 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index e4b5494f05f8..784ab8fe8714 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8250,6 +8250,37 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) return 0; } +/* + * Variation on perf_event_ctx_lock_nested(), except we take two context + * mutexes. + */ +static struct perf_event_context * +__perf_event_ctx_lock_double(struct perf_event *group_leader, + struct perf_event_context *ctx) +{ + struct perf_event_context *gctx; + +again: + rcu_read_lock(); + gctx = READ_ONCE(group_leader->ctx); + if (!atomic_inc_not_zero(&gctx->refcount)) { + rcu_read_unlock(); + goto again; + } + rcu_read_unlock(); + + mutex_lock_double(&gctx->mutex, &ctx->mutex); + + if (group_leader->ctx != gctx) { + mutex_unlock(&ctx->mutex); + mutex_unlock(&gctx->mutex); + put_ctx(gctx); + goto again; + } + + return gctx; +} + /** * sys_perf_event_open - open a performance event, associate it to a task/cpu * @@ -8486,8 +8517,26 @@ SYSCALL_DEFINE5(perf_event_open, } if (move_group) { - gctx = group_leader->ctx; - mutex_lock_double(&gctx->mutex, &ctx->mutex); + gctx = __perf_event_ctx_lock_double(group_leader, ctx); + + /* + * Check if we raced against another sys_perf_event_open() call + * moving the software group underneath us. + */ + if (!(group_leader->group_flags & PERF_GROUP_SOFTWARE)) { + /* + * If someone moved the group out from under us, check + * if this new event wound up on the same ctx, if so + * its the regular !move_group case, otherwise fail. + */ + if (gctx != ctx) { + err = -EINVAL; + goto err_locked; + } else { + perf_event_ctx_unlock(group_leader, gctx); + move_group = 0; + } + } } else { mutex_lock(&ctx->mutex); } @@ -8582,7 +8631,7 @@ SYSCALL_DEFINE5(perf_event_open, perf_unpin_context(ctx); if (move_group) - mutex_unlock(&gctx->mutex); + perf_event_ctx_unlock(group_leader, gctx); mutex_unlock(&ctx->mutex); if (task) { @@ -8610,7 +8659,7 @@ SYSCALL_DEFINE5(perf_event_open, err_locked: if (move_group) - mutex_unlock(&gctx->mutex); + perf_event_ctx_unlock(group_leader, gctx); mutex_unlock(&ctx->mutex); /* err_file: */ fput(event_file); From 418b99042b87b2b08a5d4f7f19e775f10211d431 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sun, 30 Apr 2017 05:50:11 +0200 Subject: [PATCH 18/18] Linux 4.4.65 --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 17708f5dc169..ddaef04f528a 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,6 @@ VERSION = 4 PATCHLEVEL = 4 -SUBLEVEL = 64 +SUBLEVEL = 65 EXTRAVERSION = NAME = Blurry Fish Butt