From f3d3342602f8bcbf37d7c46641cb9bca7618eb1c Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Thu, 21 Nov 2013 03:14:22 +0100 Subject: net: rework recvmsg handler msg_name and msg_namelen logic This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/tipc/socket.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 3906527259d1..3b61851bb927 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -980,9 +980,6 @@ static int recv_msg(struct kiocb *iocb, struct socket *sock, goto exit; } - /* will be updated in set_orig_addr() if needed */ - m->msg_namelen = 0; - timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); restart: @@ -1091,9 +1088,6 @@ static int recv_stream(struct kiocb *iocb, struct socket *sock, goto exit; } - /* will be updated in set_orig_addr() if needed */ - m->msg_namelen = 0; - target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len); timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); -- cgit v1.2.3 From 993b858e37b3120ee76d9957a901cca22312ffaa Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Mon, 9 Dec 2013 22:54:46 -0800 Subject: tipc: correct the order of stopping services at rmmod The 'signal handler' service in TIPC is a mechanism that makes it possible to postpone execution of functions, by launcing them into a job queue for execution in a separate tasklet, independent of the launching execution thread. When we do rmmod on the tipc module, this service is stopped after the network service. At the same time, the stopping of the network service may itself launch jobs for execution, with the risk that these functions may be scheduled for execution after the data structures meant to be accessed by the job have already been deleted. We have seen this happen, most often resulting in an oops. This commit ensures that the signal handler is the very first to be stopped when TIPC is shut down, so there are no surprises during the cleanup of the other services. Signed-off-by: Jon Maloy Reviewed-by: Paul Gortmaker Signed-off-by: David S. Miller --- net/tipc/core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/core.c b/net/tipc/core.c index fd4eeeaa972a..c6d3f75a9e1b 100644 --- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -113,7 +113,6 @@ err: static void tipc_core_stop(void) { tipc_netlink_stop(); - tipc_handler_stop(); tipc_cfg_stop(); tipc_subscr_stop(); tipc_nametbl_stop(); @@ -146,9 +145,10 @@ static int tipc_core_start(void) res = tipc_subscr_start(); if (!res) res = tipc_cfg_init(); - if (res) + if (res) { + tipc_handler_stop(); tipc_core_stop(); - + } return res; } @@ -178,6 +178,7 @@ static int __init tipc_init(void) static void __exit tipc_exit(void) { + tipc_handler_stop(); tipc_core_stop_net(); tipc_core_stop(); pr_info("Deactivated\n"); -- cgit v1.2.3 From 00ede977098be3296d42d05a4265ec5ec4a28419 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 9 Dec 2013 22:54:47 -0800 Subject: tipc: protect handler_enabled variable with qitem_lock spin lock 'handler_enabled' is a global flag indicating whether the TIPC signal handling service is enabled or not. The lack of lock protection for this flag incurs a risk for contention, so that a tipc_k_signal() call might queue a signal handler to a destroyed signal queue, with unpredictable results. To correct this, we let the already existing 'qitem_lock' protect the flag, as it already does with the queue itself. This way, we ensure that the flag always is consistent across all cores. Signed-off-by: Ying Xue Reviewed-by: Paul Gortmaker Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/handler.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/handler.c b/net/tipc/handler.c index b36f0fcd9bdf..e4bc8a296744 100644 --- a/net/tipc/handler.c +++ b/net/tipc/handler.c @@ -56,12 +56,13 @@ unsigned int tipc_k_signal(Handler routine, unsigned long argument) { struct queue_item *item; + spin_lock_bh(&qitem_lock); if (!handler_enabled) { pr_err("Signal request ignored by handler\n"); + spin_unlock_bh(&qitem_lock); return -ENOPROTOOPT; } - spin_lock_bh(&qitem_lock); item = kmem_cache_alloc(tipc_queue_item_cache, GFP_ATOMIC); if (!item) { pr_err("Signal queue out of memory\n"); @@ -112,10 +113,14 @@ void tipc_handler_stop(void) struct list_head *l, *n; struct queue_item *item; - if (!handler_enabled) + spin_lock_bh(&qitem_lock); + if (!handler_enabled) { + spin_unlock_bh(&qitem_lock); return; - + } handler_enabled = 0; + spin_unlock_bh(&qitem_lock); + tasklet_kill(&tipc_tasklet); spin_lock_bh(&qitem_lock); -- cgit v1.2.3