kernel.git/include/net/sctp/structs.h, branch linux-3.10.y

sctp: fix ASCONF list handling

2015-10-01T10:07:34Z

commit 2d45a02d0166caf2627fe91897c6ffc3b19514c4 upstream. ->auto_asconf_splist is per namespace and mangled by functions like sctp_setsockopt_auto_asconf() which doesn't guarantee any serialization. Also, the call to inet_sk_copy_descendant() was backuping ->auto_asconf_list through the copy but was not honoring ->do_auto_asconf, which could lead to list corruption if it was different between both sockets. This commit thus fixes the list handling by using ->addr_wq_lock spinlock to protect the list. A special handling is done upon socket creation and destruction for that. Error handlig on sctp_init_sock() will never return an error after having initialized asconf, so sctp_destroy_sock() can be called without addrq_wq_lock. The lock now will be take on sctp_close_sock(), before locking the socket, so we don't do it in inverse order compared to sctp_addr_wq_timeout_handler(). Instead of taking the lock on sctp_sock_migrate() for copying and restoring the list values, it's preferred to avoid rewritting it by implementing sctp_copy_descendant(). Issue was found with a test application that kept flipping sysctl default_auto_asconf on and off, but one could trigger it by issuing simultaneous setsockopt() calls on multiple sockets or by creating/destroying sockets fast enough. This is only triggerable locally. Fixes: 9f7d653b67ae ("sctp: Add Auto-ASCONF support (core).") Reported-by: Ji Jianwen Suggested-by: Neil Horman Suggested-by: Hannes Frederic Sowa Acked-by: Hannes Frederic Sowa Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller [wangkai: backport to 3.10: adjust context] Signed-off-by: Wang Kai Signed-off-by: Greg Kroah-Hartman

net: sctp: cache auth_enable per endpoint

2014-05-31T04:52:15Z

[ Upstream commit b14878ccb7fac0242db82720b784ab62c467c0dc ] Currently, it is possible to create an SCTP socket, then switch auth_enable via sysctl setting to 1 and crash the system on connect: Oops[#1]: CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.1-mipsgit-20140415 #1 task: ffffffff8056ce80 ti: ffffffff8055c000 task.ti: ffffffff8055c000 [...] Call Trace: [] sctp_auth_asoc_set_default_hmac+0x68/0x80 [] sctp_process_init+0x5e0/0x8a4 [] sctp_sf_do_5_1B_init+0x234/0x34c [] sctp_do_sm+0xb4/0x1e8 [] sctp_endpoint_bh_rcv+0x1c4/0x214 [] sctp_rcv+0x588/0x630 [] sctp6_rcv+0x10/0x24 [] ip6_input+0x2c0/0x440 [] __netif_receive_skb_core+0x4a8/0x564 [] process_backlog+0xb4/0x18c [] net_rx_action+0x12c/0x210 [] __do_softirq+0x17c/0x2ac [] irq_exit+0x54/0xb0 [] ret_from_irq+0x0/0x4 [] rm7k_wait_irqoff+0x24/0x48 [] cpu_startup_entry+0xc0/0x148 [] start_kernel+0x37c/0x398 Code: dd0900b8 000330f8 0126302d 50c0fff1 0047182a a48306a0 03e00008 00000000 ---[ end trace b530b0551467f2fd ]--- Kernel panic - not syncing: Fatal exception in interrupt What happens while auth_enable=0 in that case is, that ep->auth_hmacs is initialized to NULL in sctp_auth_init_hmacs() when endpoint is being created. After that point, if an admin switches over to auth_enable=1, the machine can crash due to NULL pointer dereference during reception of an INIT chunk. When we enter sctp_process_init() via sctp_sf_do_5_1B_init() in order to respond to an INIT chunk, the INIT verification succeeds and while we walk and process all INIT params via sctp_process_param() we find that net->sctp.auth_enable is set, therefore do not fall through, but invoke sctp_auth_asoc_set_default_hmac() instead, and thus, dereference what we have set to NULL during endpoint initialization phase. The fix is to make auth_enable immutable by caching its value during endpoint initialization, so that its original value is being carried along until destruction. The bug seems to originate from the very first days. Fix in joint work with Daniel Borkmann. Reported-by: Joshua Kinard Signed-off-by: Vlad Yasevich Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Tested-by: Joshua Kinard Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: sctp: minor: remove dead code from sctp_packet

2013-04-22T20:25:21Z

struct sctp_packet is currently embedded into sctp_transport or sits on the stack as 'singleton' in sctp_outq_flush(). Therefore, its member 'malloced' is always 0, thus a kfree() is never called. Because of that, we can just remove this code. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

net: sctp: sctp_bind_addr: remove dead code

2013-04-17T18:13:02Z

The sctp_bind_addr structure has a 'malloced' member that is always set to 0, thus in sctp_bind_addr_free() the kfree() part can never be called. This part is embedded into sctp_ep_common anyway and never alloced. Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller

net: sctp: sctp_transport: remove unused variable

2013-04-17T18:13:02Z

sctp_transport's member 'malloced' is set to 1, never evaluated and the structure is kfreed anyway. So just remove it. Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller

net: sctp: sctp_outq: remove 'malloced' from its struct

2013-04-17T18:13:02Z

sctp_outq is embedded into sctp_association, and thus never kmalloced in any way. Also, malloced is always 0, thus kfree() is never called. Therefore, remove that dead piece of code. Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller

net: sctp: sctp_inq: remove dead code

2013-04-17T18:13:02Z

sctp_inq is never kmalloced, since it's integrated into sctp_ep_common and only initialized from eps and assocs. Therefore, remove the dead code from there. Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller

net: sctp: sctp_ssnmap: remove 'malloced' element from struct

2013-04-17T18:13:02Z

sctp_ssnmap_init() can only be called from sctp_ssnmap_new() where malloced is always set to 1. Thus, when we call sctp_ssnmap_free() the test for map->malloced evaluates always to true. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

net: sctp: minor: make sctp_ep_common's member 'dead' a bool

2013-04-15T18:11:37Z

Since dead only holds two states (0,1), make it a bool instead of a 'char', which is more appropriate for its purpose. Signed-off-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

net: sctp: remove sctp_ep_common struct member 'malloced'

2013-04-15T18:11:37Z

There is actually no need to keep this member in the structure, because after init it's always 1 anyway, thus always kfree called. This seems to be an ancient leftover from the very initial implementation from 2.5 times. Only in case the initialization of an association fails, we leave base.malloced as 0, but we nevertheless kfree it in the error path in sctp_association_new(). Signed-off-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller