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2021-05-22sctp: delay auto_asconf init until binding the first addrXin Long1-14/+17
commit 34e5b01186858b36c4d7c87e1a025071e8e2401f upstream. As Or Cohen described: If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock held and sp->do_auto_asconf is true, then an element is removed from the auto_asconf_splist without any proper locking. This can happen in the following functions: 1. In sctp_accept, if sctp_sock_migrate fails. 2. In inet_create or inet6_create, if there is a bpf program attached to BPF_CGROUP_INET_SOCK_CREATE which denies creation of the sctp socket. This patch is to fix it by moving the auto_asconf init out of sctp_init_sock(), by which inet_create()/inet6_create() won't need to operate it in sctp_destroy_sock() when calling sk_common_release(). It also makes more sense to do auto_asconf init while binding the first addr, as auto_asconf actually requires an ANY addr bind, see it in sctp_addr_wq_timeout_handler(). This addresses CVE-2021-23133. Fixes: 610236587600 ("bpf: Add new cgroup attach type to enable sock modifications") Reported-by: Or Cohen <orcohen@paloaltonetworks.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22Revert "net/sctp: fix race condition in sctp_destroy_sock"Xin Long1-5/+8
commit 01bfe5e8e428b475982a98a46cca5755726f3f7f upstream. This reverts commit b166a20b07382b8bc1dcee2a448715c9c2c81b5b. This one has to be reverted as it introduced a dead lock, as syzbot reported: CPU0 CPU1 ---- ---- lock(&net->sctp.addr_wq_lock); lock(slock-AF_INET6); lock(&net->sctp.addr_wq_lock); lock(slock-AF_INET6); CPU0 is the thread of sctp_addr_wq_timeout_handler(), and CPU1 is that of sctp_close(). The original issue this commit fixed will be fixed in the next patch. Reported-by: syzbot+959223586843e69a2674@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-28net/sctp: fix race condition in sctp_destroy_sockOr Cohen1-8/+5
commit b166a20b07382b8bc1dcee2a448715c9c2c81b5b upstream. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock held and sp->do_auto_asconf is true, then an element is removed from the auto_asconf_splist without any proper locking. This can happen in the following functions: 1. In sctp_accept, if sctp_sock_migrate fails. 2. In inet_create or inet6_create, if there is a bpf program attached to BPF_CGROUP_INET_SOCK_CREATE which denies creation of the sctp socket. The bug is fixed by acquiring addr_wq_lock in sctp_destroy_sock instead of sctp_close. This addresses CVE-2021-23133. Reported-by: Or Cohen <orcohen@paloaltonetworks.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Fixes: 610236587600 ("bpf: Add new cgroup attach type to enable sock modifications") Signed-off-by: Or Cohen <orcohen@paloaltonetworks.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12sctp: not disable bh in the whole sctp_get_port_local()Xin Long1-10/+6
[ Upstream commit 3106ecb43a05dc3e009779764b9da245a5d082de ] With disabling bh in the whole sctp_get_port_local(), when snum == 0 and too many ports have been used, the do-while loop will take the cpu for a long time and cause cpu stuck: [ ] watchdog: BUG: soft lockup - CPU#11 stuck for 22s! [ ] RIP: 0010:native_queued_spin_lock_slowpath+0x4de/0x940 [ ] Call Trace: [ ] _raw_spin_lock+0xc1/0xd0 [ ] sctp_get_port_local+0x527/0x650 [sctp] [ ] sctp_do_bind+0x208/0x5e0 [sctp] [ ] sctp_autobind+0x165/0x1e0 [sctp] [ ] sctp_connect_new_asoc+0x355/0x480 [sctp] [ ] __sctp_connect+0x360/0xb10 [sctp] There's no need to disable bh in the whole function of sctp_get_port_local. So fix this cpu stuck by removing local_bh_disable() called at the beginning, and using spin_lock_bh() instead. The same thing was actually done for inet_csk_get_port() in Commit ea8add2b1903 ("tcp/dccp: better use of ephemeral ports in bind()"). Thanks to Marcelo for pointing the buggy code out. v1->v2: - use cond_resched() to yield cpu to other tasks if needed, as Eric noticed. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Ying Xu <yinxu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02sctp: use right member as the param of list_for_each_entryXin Long1-3/+3
commit a8dd397903a6e57157f6265911f7d35681364427 upstream. Commit d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues when migrating a sock") made a mistake that using 'list' as the param of list_for_each_entry to traverse the retransmit, sacked and abandoned queues, while chunks are using 'transmitted_list' to link into these queues. It could cause NULL dereference panic if there are chunks in any of these queues when peeling off one asoc. So use the chunk member 'transmitted_list' instead in this patch. Fixes: d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues when migrating a sock") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10inet: stop leaking jiffies on the wireEric Dumazet1-1/+1
[ Upstream commit a904a0693c189691eeee64f6c6b188bd7dc244e9 ] Historically linux tried to stick to RFC 791, 1122, 2003 for IPv4 ID field generation. RFC 6864 made clear that no matter how hard we try, we can not ensure unicity of IP ID within maximum lifetime for all datagrams with a given source address/destination address/protocol tuple. Linux uses a per socket inet generator (inet_id), initialized at connection startup with a XOR of 'jiffies' and other fields that appear clear on the wire. Thiemo Nagel pointed that this strategy is a privacy concern as this provides 16 bits of entropy to fingerprint devices. Let's switch to a random starting point, this is just as good as far as RFC 6864 is concerned and does not leak anything critical. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Thiemo Nagel <tnagel@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06sctp: not bind the socket in sctp_connectXin Long1-19/+2
commit 9b6c08878e23adb7cc84bdca94d8a944b03f099e upstream. Now when sctp_connect() is called with a wrong sa_family, it binds to a port but doesn't set bp->port, then sctp_get_af_specific will return NULL and sctp_connect() returns -EINVAL. Then if sctp_bind() is called to bind to another port, the last port it has bound will leak due to bp->port is NULL by then. sctp_connect() doesn't need to bind ports, as later __sctp_connect will do it if bp->port is NULL. So remove it from sctp_connect(). While at it, remove the unnecessary sockaddr.sa_family len check as it's already done in sctp_inet_connect. Fixes: 644fbdeacf1d ("sctp: fix the issue that flags are ignored when using kernel_connect") Reported-by: syzbot+079bf326b38072f849d9@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06sctp: fix the issue that flags are ignored when using kernel_connectXin Long1-18/+38
commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream. Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags param can't be passed into its proto .connect where this flags is really needed. sctp works around it by getting flags from socket file in __sctp_connect. It works for connecting from userspace, as inherently the user sock has socket file and it passes f_flags as the flags param into the proto_ops .connect. However, the sock created by sock_create_kern doesn't have a socket file, and it passes the flags (like O_NONBLOCK) by using the flags param in kernel_connect, which calls proto_ops .connect later. So to fix it, this patch defines a new proto_ops .connect for sctp, sctp_inet_connect, which calls __sctp_connect() directly with this flags param. After this, the sctp's proto .connect can be removed. Note that sctp_inet_connect doesn't need to do some checks that are not needed for sctp, which makes thing better than with inet_dgram_connect. Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-29sctp: change sctp_prot .no_autobind with trueXin Long1-2/+2
[ Upstream commit 63dfb7938b13fa2c2fbcb45f34d065769eb09414 ] syzbot reported a memory leak: BUG: memory leak, unreferenced object 0xffff888120b3d380 (size 64): backtrace: [...] slab_alloc mm/slab.c:3319 [inline] [...] kmem_cache_alloc+0x13f/0x2c0 mm/slab.c:3483 [...] sctp_bucket_create net/sctp/socket.c:8523 [inline] [...] sctp_get_port_local+0x189/0x5a0 net/sctp/socket.c:8270 [...] sctp_do_bind+0xcc/0x200 net/sctp/socket.c:402 [...] sctp_bindx_add+0x4b/0xd0 net/sctp/socket.c:497 [...] sctp_setsockopt_bindx+0x156/0x1b0 net/sctp/socket.c:1022 [...] sctp_setsockopt net/sctp/socket.c:4641 [inline] [...] sctp_setsockopt+0xaea/0x2dc0 net/sctp/socket.c:4611 [...] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3147 [...] __sys_setsockopt+0x10f/0x220 net/socket.c:2084 [...] __do_sys_setsockopt net/socket.c:2100 [inline] It was caused by when sending msgs without binding a port, in the path: inet_sendmsg() -> inet_send_prepare() -> inet_autobind() -> .get_port/sctp_get_port(), sp->bind_hash will be set while bp->port is not. Later when binding another port by sctp_setsockopt_bindx(), a new bucket will be created as bp->port is not set. sctp's autobind is supposed to call sctp_autobind() where it does all things including setting bp->port. Since sctp_autobind() is called in sctp_sendmsg() if the sk is not yet bound, it should have skipped the auto bind. THis patch is to avoid calling inet_autobind() in inet_send_prepare() by changing sctp_prot .no_autobind with true, also remove the unused .get_port. Reported-by: syzbot+d44f7bbebdea49dbc84a@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-10sctp: fix race on sctp_id2asocMarcelo Ricardo Leitner1-3/+2
[ Upstream commit b336decab22158937975293aea79396525f92bb3 ] syzbot reported an use-after-free involving sctp_id2asoc. Dmitry Vyukov helped to root cause it and it is because of reading the asoc after it was freed: CPU 1 CPU 2 (working on socket 1) (working on socket 2) sctp_association_destroy sctp_id2asoc spin lock grab the asoc from idr spin unlock spin lock remove asoc from idr spin unlock free(asoc) if asoc->base.sk != sk ... [*] This can only be hit if trying to fetch asocs from different sockets. As we have a single IDR for all asocs, in all SCTP sockets, their id is unique on the system. An application can try to send stuff on an id that matches on another socket, and the if in [*] will protect from such usage. But it didn't consider that as that asoc may belong to another socket, it may be freed in parallel (read: under another socket lock). We fix it by moving the checks in [*] into the protected region. This fixes it because the asoc cannot be freed while the lock is held. Reported-by: syzbot+c7dd55d7aec49d48e49a@syzkaller.appspotmail.com Acked-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13sctp: sctp_sockaddr_af must check minimal addr length for AF_INET6Eric Dumazet1-5/+8
[ Upstream commit 81e98370293afcb58340ce8bd71af7b97f925c26 ] Check must happen before call to ipv6_addr_v4mapped() syzbot report was : BUG: KMSAN: uninit-value in sctp_sockaddr_af net/sctp/socket.c:359 [inline] BUG: KMSAN: uninit-value in sctp_do_bind+0x60f/0xdc0 net/sctp/socket.c:384 CPU: 0 PID: 3576 Comm: syzkaller968804 Not tainted 4.16.0+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 sctp_sockaddr_af net/sctp/socket.c:359 [inline] sctp_do_bind+0x60f/0xdc0 net/sctp/socket.c:384 sctp_bind+0x149/0x190 net/sctp/socket.c:332 inet6_bind+0x1fd/0x1820 net/ipv6/af_inet6.c:293 SYSC_bind+0x3f2/0x4b0 net/socket.c:1474 SyS_bind+0x54/0x80 net/socket.c:1460 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x43fd49 RSP: 002b:00007ffe99df3d28 EFLAGS: 00000213 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd49 RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401670 R13: 0000000000401700 R14: 0000000000000000 R15: 0000000000000000 Local variable description: ----address@SYSC_bind Variable was created at: SYSC_bind+0x6f/0x4b0 net/socket.c:1461 SyS_bind+0x54/0x80 net/socket.c:1460 Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13sctp: fix recursive locking warning in sctp_do_peeloffXin Long1-2/+2
[ Upstream commit 6dfe4b97e08ec3d1a593fdaca099f0ef0a3a19e6 ] Dmitry got the following recursive locking report while running syzkaller fuzzer, the Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:52 print_deadlock_bug kernel/locking/lockdep.c:1729 [inline] check_deadlock kernel/locking/lockdep.c:1773 [inline] validate_chain kernel/locking/lockdep.c:2251 [inline] __lock_acquire+0xef2/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 lock_sock_nested+0xcb/0x120 net/core/sock.c:2536 lock_sock include/net/sock.h:1460 [inline] sctp_close+0xcd/0x9d0 net/sctp/socket.c:1497 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 sock_release+0x8d/0x1e0 net/socket.c:597 __sock_create+0x38b/0x870 net/socket.c:1226 sock_create+0x7f/0xa0 net/socket.c:1237 sctp_do_peeloff+0x1a2/0x440 net/sctp/socket.c:4879 sctp_getsockopt_peeloff net/sctp/socket.c:4914 [inline] sctp_getsockopt+0x111a/0x67e0 net/sctp/socket.c:6628 sock_common_getsockopt+0x95/0xd0 net/core/sock.c:2690 SYSC_getsockopt net/socket.c:1817 [inline] SyS_getsockopt+0x240/0x380 net/socket.c:1799 entry_SYSCALL_64_fastpath+0x1f/0xc2 This warning is caused by the lock held by sctp_getsockopt() is on one socket, while the other lock that sctp_close() is getting later is on the newly created (which failed) socket during peeloff operation. This patch is to avoid this warning by use lock_sock with subclass SINGLE_DEPTH_NESTING as Wang Cong and Marcelo's suggestion. Reported-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Suggested-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-03sctp: make use of pre-calculated lenMarcelo Ricardo Leitner1-6/+10
[ Upstream commit c76f97c99ae6d26d14c7f0e50e074382bfbc9f98 ] Some sockopt handling functions were calculating the length of the buffer to be written to userspace and then calculating it again when actually writing the buffer, which could lead to some write not using an up-to-date length. This patch updates such places to just make use of the len variable. Also, replace some sizeof(type) to sizeof(var). Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31sctp: return error if the asoc has been peeled off in sctp_wait_for_sndbufXin Long1-10/+6
[ Upstream commit a0ff660058b88d12625a783ce9e5c1371c87951f ] After commit cea0cc80a677 ("sctp: use the right sk after waking up from wait_buf sleep"), it may change to lock another sk if the asoc has been peeled off in sctp_wait_for_sndbuf. However, the asoc's new sk could be already closed elsewhere, as it's in the sendmsg context of the old sk that can't avoid the new sk's closing. If the sk's last one refcnt is held by this asoc, later on after putting this asoc, the new sk will be freed, while under it's own lock. This patch is to revert that commit, but fix the old issue by returning error under the old sk's lock. Fixes: cea0cc80a677 ("sctp: use the right sk after waking up from wait_buf sleep") Reported-by: syzbot+ac6ea7baa4432811eb50@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31sctp: do not allow the v4 socket to bind a v4mapped v6 addressXin Long1-8/+6
[ Upstream commit c5006b8aa74599ce19104b31d322d2ea9ff887cc ] The check in sctp_sockaddr_af is not robust enough to forbid binding a v4mapped v6 addr on a v4 socket. The worse thing is that v4 socket's bind_verify would not convert this v4mapped v6 addr to a v4 addr. syzbot even reported a crash as the v4 socket bound a v6 addr. This patch is to fix it by doing the common sa.sa_family check first, then AF_INET check for v4mapped v6 addrs. Fixes: 7dab83de50c7 ("sctp: Support ipv6only AF_INET6 sockets.") Reported-by: syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02sctp: Replace use of sockets_allocated with specified macro.Tonghao Zhang1-2/+2
[ Upstream commit 8cb38a602478e9f806571f6920b0a3298aabf042 ] The patch(180d8cd942ce) replaces all uses of struct sock fields' memory_pressure, memory_allocated, sockets_allocated, and sysctl_mem to accessor macros. But the sockets_allocated field of sctp sock is not replaced at all. Then replace it now for unifying the code. Fixes: 180d8cd942ce ("foundations of per-cgroup memory pressure controlling.") Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Tonghao Zhang <zhangtonghao@didichuxing.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-16sctp: use the right sk after waking up from wait_buf sleepXin Long1-10/+11
[ Upstream commit cea0cc80a6777beb6eb643d4ad53690e1ad1d4ff ] Commit dfcb9f4f99f1 ("sctp: deny peeloff operation on asocs with threads sleeping on it") fixed the race between peeloff and wait sndbuf by checking waitqueue_active(&asoc->wait) in sctp_do_peeloff(). But it actually doesn't work, as even if waitqueue_active returns false the waiting sndbuf thread may still not yet hold sk lock. After asoc is peeled off, sk is not asoc->base.sk any more, then to hold the old sk lock couldn't make assoc safe to access. This patch is to fix this by changing to hold the new sk lock if sk is not asoc->base.sk, meanwhile, also set the sk in sctp_sendmsg with the new sk. With this fix, there is no more race between peeloff and waitbuf, the check 'waitqueue_active' in sctp_do_peeloff can be removed. Thanks Marcelo and Neil for making this clear. v1->v2: fix it by changing to lock the new sock instead of adding a flag in asoc. Suggested-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-16sctp: do not free asoc when it is already dead in sctp_sendmsgXin Long1-3/+14
[ Upstream commit ca3af4dd28cff4e7216e213ba3b671fbf9f84758 ] Now in sctp_sendmsg sctp_wait_for_sndbuf could schedule out without holding sock sk. It means the current asoc can be freed elsewhere, like when receiving an abort packet. If the asoc is just created in sctp_sendmsg and sctp_wait_for_sndbuf returns err, the asoc will be freed again due to new_asoc is not nil. An use-after-free issue would be triggered by this. This patch is to fix it by setting new_asoc with nil if the asoc is already dead when cpu schedules back, so that it will not be freed again in sctp_sendmsg. v1->v2: set new_asoc as nil in sctp_sendmsg instead of sctp_wait_for_sndbuf. Suggested-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30Revert "sctp: do not peel off an assoc from one netns to another one"Greg Kroah-Hartman1-4/+0
This reverts commit 2a0e60907e54dad75e9b3568d02bec11d6e74f6b which is commit df80cd9b28b9ebaa284a41df611dbf3a2d05ca74 upstream as I messed up by applying it to the tree twice. Reported-by: Michal Kubecek <mkubecek@suse.cz> Cc: ChunYu Wang <chunwang@redhat.com> Cc: Xin Long <lucien.xin@gmail.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-24sctp: do not peel off an assoc from one netns to another oneXin Long1-0/+4
[ Upstream commit df80cd9b28b9ebaa284a41df611dbf3a2d05ca74 ] Now when peeling off an association to the sock in another netns, all transports in this assoc are not to be rehashed and keep use the old key in hashtable. As a transport uses sk->net as the hash key to insert into hashtable, it would miss removing these transports from hashtable due to the new netns when closing the sock and all transports are being freeed, then later an use-after-free issue could be caused when looking up an asoc and dereferencing those transports. This is a very old issue since very beginning, ChunYu found it with syzkaller fuzz testing with this series: socket$inet6_sctp() bind$inet6() sendto$inet6() unshare(0x40000000) getsockopt$inet_sctp6_SCTP_GET_ASSOC_ID_LIST() getsockopt$inet_sctp6_SCTP_SOCKOPT_PEELOFF() This patch is to block this call when peeling one assoc off from one netns to another one, so that the netns of all transport would not go out-sync with the key in hashtable. Note that this patch didn't fix it by rehashing transports, as it's difficult to handle the situation when the tuple is already in use in the new netns. Besides, no one would like to peel off one assoc to another netns, considering ipaddrs, ifaces, etc. are usually different. Reported-by: ChunYu Wang <chunwang@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-21sctp: do not peel off an assoc from one netns to another oneXin Long1-0/+4
commit df80cd9b28b9ebaa284a41df611dbf3a2d05ca74 upstream. Now when peeling off an association to the sock in another netns, all transports in this assoc are not to be rehashed and keep use the old key in hashtable. As a transport uses sk->net as the hash key to insert into hashtable, it would miss removing these transports from hashtable due to the new netns when closing the sock and all transports are being freeed, then later an use-after-free issue could be caused when looking up an asoc and dereferencing those transports. This is a very old issue since very beginning, ChunYu found it with syzkaller fuzz testing with this series: socket$inet6_sctp() bind$inet6() sendto$inet6() unshare(0x40000000) getsockopt$inet_sctp6_SCTP_GET_ASSOC_ID_LIST() getsockopt$inet_sctp6_SCTP_SOCKOPT_PEELOFF() This patch is to block this call when peeling one assoc off from one netns to another one, so that the netns of all transport would not go out-sync with the key in hashtable. Note that this patch didn't fix it by rehashing transports, as it's difficult to handle the situation when the tuple is already in use in the new netns. Besides, no one would like to peel off one assoc to another netns, considering ipaddrs, ifaces, etc. are usually different. Reported-by: ChunYu Wang <chunwang@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-18sctp: reset owner sk for data chunks on out queues when migrating a sockXin Long1-0/+32
[ Upstream commit d04adf1b355181e737b6b1e23d801b07f0b7c4c0 ] Now when migrating sock to another one in sctp_sock_migrate(), it only resets owner sk for the data in receive queues, not the chunks on out queues. It would cause that data chunks length on the sock is not consistent with sk sk_wmem_alloc. When closing the sock or freeing these chunks, the old sk would never be freed, and the new sock may crash due to the overflow sk_wmem_alloc. syzbot found this issue with this series: r0 = socket$inet_sctp() sendto$inet(r0) listen(r0) accept4(r0) close(r0) Although listen() should have returned error when one TCP-style socket is in connecting (I may fix this one in another patch), it could also be reproduced by peeling off an assoc. This issue is there since very beginning. This patch is to reset owner sk for the chunks on out queues so that sk sk_wmem_alloc has correct value after accept one sock or peeloff an assoc to one sock. Note that when resetting owner sk for chunks on outqueue, it has to sctp_clear_owner_w/skb_orphan chunks before changing assoc->base.sk first and then sctp_set_owner_w them after changing assoc->base.sk, due to that sctp_wfree and it's callees are using assoc->base.sk. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05sctp: check af before verify address in sctp_addr_id2transportXin Long1-1/+1
[ Upstream commit 912964eacb111551db73429719eb5fadcab0ff8a ] Commit 6f29a1306131 ("sctp: sctp_addr_id2transport should verify the addr before looking up assoc") invoked sctp_verify_addr to verify the addr. But it didn't check af variable beforehand, once users pass an address with family = 0 through sockopt, sctp_get_af_specific will return NULL and NULL pointer dereference will be caused by af->sockaddr_len. This patch is to fix it by returning NULL if af variable is NULL. Fixes: 6f29a1306131 ("sctp: sctp_addr_id2transport should verify the addr before looking up assoc") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17sctp: sctp_addr_id2transport should verify the addr before looking up assocXin Long1-1/+5
[ Upstream commit 6f29a130613191d3c6335169febe002cba00edf5 ] sctp_addr_id2transport is a function for sockopt to look up assoc by address. As the address is from userspace, it can be a v4-mapped v6 address. But in sctp protocol stack, it always handles a v4-mapped v6 address as a v4 address. So it's necessary to convert it to a v4 address before looking up assoc by address. This patch is to fix it by calling sctp_verify_addr in which it can do this conversion before calling sctp_endpoint_lookup_assoc, just like what sctp_sendmsg and __sctp_connect do for the address from users. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03sctp: listen on the sock only when it's state is listening or closedXin Long1-0/+3
[ Upstream commit 34b2789f1d9bf8dcca9b5cb553d076ca2cd898ee ] Now sctp doesn't check sock's state before listening on it. It could even cause changing a sock with any state to become a listening sock when doing sctp_listen. This patch is to fix it by checking sock's state in sctp_listen, so that it will listen on the sock with right state. Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21sctp: deny peeloff operation on asocs with threads sleeping on itMarcelo Ricardo Leitner1-2/+6
commit dfcb9f4f99f1e9a49e43398a7bfbf56927544af1 upstream. commit 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf") attempted to avoid a BUG_ON call when the association being used for a sendmsg() is blocked waiting for more sndbuf and another thread did a peeloff operation on such asoc, moving it to another socket. As Ben Hutchings noticed, then in such case it would return without locking back the socket and would cause two unlocks in a row. Further analysis also revealed that it could allow a double free if the application managed to peeloff the asoc that is created during the sendmsg call, because then sctp_sendmsg() would try to free the asoc that was created only for that call. This patch takes another approach. It will deny the peeloff operation if there is a thread sleeping on the asoc, so this situation doesn't exist anymore. This avoids the issues described above and also honors the syscalls that are already being handled (it can be multiple sendmsg calls). Joint work with Xin Long. Fixes: 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf") Cc: Alexander Popov <alex.popov@linux.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-18sctp: avoid BUG_ON on sctp_wait_for_sndbufMarcelo Ricardo Leitner1-1/+2
[ Upstream commit 2dcab598484185dea7ec22219c76dcdd59e3cb90 ] Alexander Popov reported that an application may trigger a BUG_ON in sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is waiting on it to queue more data and meanwhile another thread peels off the association being used by the first thread. This patch replaces the BUG_ON call with a proper error handling. It will return -EPIPE to the original sendmsg call, similarly to what would have been done if the association wasn't found in the first place. Acked-by: Alexander Popov <alex.popov@linux.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-21sctp: assign assoc_id earlier in __sctp_connectMarcelo Ricardo Leitner1-2/+5
[ Upstream commit 7233bc84a3aeda835d334499dc00448373caf5c0 ] sctp_wait_for_connect() currently already holds the asoc to keep it alive during the sleep, in case another thread release it. But Andrey Konovalov and Dmitry Vyukov reported an use-after-free in such situation. Problem is that __sctp_connect() doesn't get a ref on the asoc and will do a read on the asoc after calling sctp_wait_for_connect(), but by then another thread may have closed it and the _put on sctp_wait_for_connect will actually release it, causing the use-after-free. Fix is, instead of doing the read after waiting for the connect, do it before so, and avoid this issue as the socket is still locked by then. There should be no issue on returning the asoc id in case of failure as the application shouldn't trust on that number in such situations anyway. This issue doesn't exist in sctp_sendmsg() path. Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-15net: sctp, forbid negative lengthJiri Slaby1-1/+4
[ Upstream commit a4b8e71b05c27bae6bad3bdecddbc6b68a3ad8cf ] Most of getsockopt handlers in net/sctp/socket.c check len against sizeof some structure like: if (len < sizeof(int)) return -EINVAL; On the first look, the check seems to be correct. But since len is int and sizeof returns size_t, int gets promoted to unsigned size_t too. So the test returns false for negative lengths. Yes, (-1 < sizeof(long)) is false. Fix this in sctp by explicitly checking len < 0 before any getsockopt handler is called. Note that sctp_getsockopt_events already handled the negative case. Since we added the < 0 check elsewhere, this one can be removed. If not checked, this is the result: UBSAN: Undefined behaviour in ../mm/page_alloc.c:2722:19 shift exponent 52 is too large for 32-bit type 'int' CPU: 1 PID: 24535 Comm: syz-executor Not tainted 4.8.1-0-syzkaller #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 0000000000000000 ffff88006d99f2a8 ffffffffb2f7bdea 0000000041b58ab3 ffffffffb4363c14 ffffffffb2f7bcde ffff88006d99f2d0 ffff88006d99f270 0000000000000000 0000000000000000 0000000000000034 ffffffffb5096422 Call Trace: [<ffffffffb3051498>] ? __ubsan_handle_shift_out_of_bounds+0x29c/0x300 ... [<ffffffffb273f0e4>] ? kmalloc_order+0x24/0x90 [<ffffffffb27416a4>] ? kmalloc_order_trace+0x24/0x220 [<ffffffffb2819a30>] ? __kmalloc+0x330/0x540 [<ffffffffc18c25f4>] ? sctp_getsockopt_local_addrs+0x174/0xca0 [sctp] [<ffffffffc18d2bcd>] ? sctp_getsockopt+0x10d/0x1b0 [sctp] [<ffffffffb37c1219>] ? sock_common_getsockopt+0xb9/0x150 [<ffffffffb37be2f5>] ? SyS_getsockopt+0x1a5/0x270 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-sctp@vger.kernel.org Cc: netdev@vger.kernel.org Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-04sctp: translate network order to host order when users get a hmacidXin Long1-2/+7
[ Upstream commit 7a84bd46647ff181eb2659fdc99590e6f16e501d ] Commit ed5a377d87dc ("sctp: translate host order to network order when setting a hmacid") corrected the hmacid byte-order when setting a hmacid. but the same issue also exists on getting a hmacid. We fix it by changing hmacids to host order when users get them with getsockopt. Fixes: Commit ed5a377d87dc ("sctp: translate host order to network order when setting a hmacid") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-04sctp: allow setting SCTP_SACK_IMMEDIATELY by the applicationMarcelo Ricardo Leitner1-0/+2
[ Upstream commit 27f7ed2b11d42ab6d796e96533c2076ec220affc ] This patch extends commit b93d6471748d ("sctp: implement the sender side for SACK-IMMEDIATELY extension") as it didn't white list SCTP_SACK_IMMEDIATELY on sctp_msghdr_parse(), causing it to be understood as an invalid flag and returning -EINVAL to the application. Note that the actual handling of the flag is already there in sctp_datamsg_from_user(). https://tools.ietf.org/html/rfc7053#section-7 Fixes: b93d6471748d ("sctp: implement the sender side for SACK-IMMEDIATELY extension") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-31sctp: sctp should release assoc when sctp_make_abort_user return NULL in ↵Xin Long1-2/+1
sctp_close In sctp_close, sctp_make_abort_user may return NULL because of memory allocation failure. If this happens, it will bypass any state change and never free the assoc. The assoc has no chance to be freed and it will be kept in memory with the state it had even after the socket is closed by sctp_close(). So if sctp_make_abort_user fails to allocate memory, we should abort the asoc via sctp_primitive_ABORT as well. Just like the annotation in sctp_sf_cookie_wait_prm_abort and sctp_sf_do_9_1_prm_abort said, "Even if we can't send the ABORT due to low memory delete the TCB. This is a departure from our typical NOMEM handling". But then the chunk is NULL (low memory) and the SCTP_CMD_REPLY cmd would dereference the chunk pointer, and system crash. So we should add SCTP_CMD_REPLY cmd only when the chunk is not NULL, just like other places where it adds SCTP_CMD_REPLY cmd. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-28sctp: label accepted/peeled off socketsMarcelo Ricardo Leitner1-0/+2
Accepted or peeled off sockets were missing a security label (e.g. SELinux) which means that socket was in "unlabeled" state. This patch clones the sock's label from the parent sock and resolves the issue (similar to AF_BLUETOOTH protocol family). Cc: Paul Moore <pmoore@redhat.com> Cc: David Teigland <teigland@redhat.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-28sctp: use GFP_USER for user-controlled kmallocMarcelo Ricardo Leitner1-3/+6
Commit cacc06215271 ("sctp: use GFP_USER for user-controlled kmalloc") missed two other spots. For connectx, as it's more likely to be used by kernel users of the API, it detects if GFP_USER should be used or not. Fixes: cacc06215271 ("sctp: use GFP_USER for user-controlled kmalloc") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-06sctp: only drop the reference on the datamsg after sending a msglucien1-4/+2
If the chunks are enqueued successfully but sctp_cmd_interpreter() return err to sctp_sendmsg() (mainly because of no mem), the chunks will get re-queued, but we are dropping the reference and freeing them. The fix is to just drop the reference on the datamsg just as it had succeeded, as: - if the chunks weren't queued, this is enough to get them freed. - if they were queued, they will get freed when they finally get out or discarded. Signed-off-by: Xin Long <lucien.xin@gmail.com> Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-06sctp: hold the chunks only after the chunk is enqueued in outqlucien1-2/+0
When a msg is sent, sctp will hold the chunks of this msg and then try to enqueue them. But if the chunks are not enqueued in sctp_outq_tail() because of the invalid state, sctp_cmd_interpreter() may still return success to sctp_sendmsg() after calling sctp_outq_flush(), these chunks will become orphans and will leak. So we fix them by moving sctp_chunk_hold() to sctp_outq_tail(), where we are sure that the chunk is going to get queued. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-06sctp: also copy sk_tsflags when copying the socketMarcelo Ricardo Leitner1-0/+1
As we are keeping timestamps on when copying the socket, we also have to copy sk_tsflags. This is needed since b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags"). Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-06sctp: update the netstamp_needed counter when copying socketsMarcelo Ricardo Leitner1-0/+3
Dmitry Vyukov reported that SCTP was triggering a WARN on socket destroy related to disabling sock timestamp. When SCTP accepts an association or peel one off, it copies sock flags but forgot to call net_enable_timestamp() if a packet timestamping flag was copied, leading to extra calls to net_disable_timestamp() whenever such clones were closed. The fix is to call net_enable_timestamp() whenever we copy a sock with that flag on, like tcp does. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03ipv6: sctp: implement sctp_v6_destroy_sock()Eric Dumazet1-1/+8
Dmitry Vyukov reported a memory leak using IPV6 SCTP sockets. We need to call inet6_destroy_sock() to properly release inet6 specific fields. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03sctp: use GFP_USER for user-controlled kmallocMarcelo Ricardo Leitner1-2/+2
Dmitry Vyukov reported that the user could trigger a kernel warning by using a large len value for getsockopt SCTP_GET_LOCAL_ADDRS, as that value directly affects the value used as a kmalloc() parameter. This patch thus switches the allocation flags from all user-controllable kmalloc size to GFP_USER to put some more restrictions on it and also disables the warn, as they are not necessary. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: fix sock_wake_async() rcu protectionEric Dumazet1-10/+14
Dmitry provided a syzkaller (http://github.com/google/syzkaller) triggering a fault in sock_wake_async() when async IO is requested. Said program stressed af_unix sockets, but the issue is generic and should be addressed in core networking stack. The problem is that by the time sock_wake_async() is called, we should not access the @flags field of 'struct socket', as the inode containing this socket might be freed without further notice, and without RCU grace period. We already maintain an RCU protected structure, "struct socket_wq" so moving SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA into it is the safe route. It also reduces number of cache lines needing dirtying, so might provide a performance improvement anyway. In followup patches, we might move remaining flags (SOCK_NOSPACE, SOCK_PASSCRED, SOCK_PASSSEC) to save 8 bytes and let 'struct socket' being mostly read and let it being shared between cpus. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATAEric Dumazet1-1/+1
This patch is a cleanup to make following patch easier to review. Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA from (struct socket)->flags to a (struct socket_wq)->flags to benefit from RCU protection in sock_wake_async() To ease backports, we rename both constants. Two new helpers, sk_set_bit(int nr, struct sock *sk) and sk_clear_bit(int net, struct sock *sk) are added so that following patch can change their implementation. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29net: Drop unlikely before IS_ERR(_OR_NULL)Viresh Kumar1-1/+1
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there is no need to do that again from its callers. Drop it. Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-07-27net: sctp: stop spamming klog with rfc6458, 5.3.2. deprecation warningsDaniel Borkmann1-6/+0
Back then when we added support for SCTP_SNDINFO/SCTP_RCVINFO from RFC6458 5.3.4/5.3.5, we decided to add a deprecation warning for the (as per RFC deprecated) SCTP_SNDRCV via commit bbbea41d5e53 ("net: sctp: deprecate rfc6458, 5.3.2. SCTP_SNDRCV support"), see [1]. Imho, it was not a good idea, and we should just revert that message for a couple of reasons: 1) It's uapi and therefore set in stone forever. 2) To be able to run on older and newer kernels, an SCTP application would need to probe for both, SCTP_SNDRCV, but also SCTP_SNDINFO/ SCTP_RCVINFO support, so that on older kernels, it can make use of SCTP_SNDRCV, and on newer kernels SCTP_SNDINFO/SCTP_RCVINFO. In my (limited) experience, a lot of SCTP appliances are migrating to newer kernels only ve(ee)ry slowly. 3) Some people don't have the chance to change their applications, f.e. due to proprietary legacy stuff. So, they'll hit this warning in fast path and are stuck with older kernels. But i.e. due to point 1) I really fail to see the benefit of a warning. So just revert that for now, the issue was reported up Jamal. [1] http://thread.gmane.org/gmane.linux.network/321960/ Reported-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Michael Tuexen <tuexen@fh-muenster.de> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-29net: Kill sock->sk_protinfoDavid Miller1-6/+0
No more users, so it can now be removed. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-14sctp: fix ASCONF list handlingMarcelo Ricardo Leitner1-11/+32
->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 <jiji@redhat.com> Suggested-by: Neil Horman <nhorman@tuxdriver.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-25sctp: avoid to repeatedly declare external variablesYing Xue1-5/+0
Move the declaration for external variables to sctp.h file avoiding to repeatedly declare them with extern keyword. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02net: Remove iocb argument from sendmsg and recvmsgYing Xue1-5/+3
After TIPC doesn't depend on iocb argument in its internal implementations of sendmsg() and recvmsg() hooks defined in proto structure, no any user is using iocb argument in them at all now. Then we can drop the redundant iocb argument completely from kinds of implementations of both sendmsg() and recvmsg() in the entire networking stack. Cc: Christoph Hellwig <hch@lst.de> Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-18net: sctp: fix race for one-to-many sockets in sendmsg's auto associateDaniel Borkmann1-1/+7
I.e. one-to-many sockets in SCTP are not required to explicitly call into connect(2) or sctp_connectx(2) prior to data exchange. Instead, they can directly invoke sendmsg(2) and the SCTP stack will automatically trigger connection establishment through 4WHS via sctp_primitive_ASSOCIATE(). However, this in its current implementation is racy: INIT is being sent out immediately (as it cannot be bundled anyway) and the rest of the DATA chunks are queued up for later xmit when connection is established, meaning sendmsg(2) will return successfully. This behaviour can result in an undesired side-effect that the kernel made the application think the data has already been transmitted, although none of it has actually left the machine, worst case even after close(2)'ing the socket. Instead, when the association from client side has been shut down e.g. first gracefully through SCTP_EOF and then close(2), the client could afterwards still receive the server's INIT_ACK due to a connection with higher latency. This INIT_ACK is then considered out of the blue and hence responded with ABORT as there was no alive assoc found anymore. This can be easily reproduced f.e. with sctp_test application from lksctp. One way to fix this race is to wait for the handshake to actually complete. The fix defers waiting after sctp_primitive_ASSOCIATE() and sctp_primitive_SEND() succeeded, so that DATA chunks cooked up from sctp_sendmsg() have already been placed into the output queue through the side-effect interpreter, and therefore can then be bundeled together with COOKIE_ECHO control chunks. strace from example application (shortened): socket(PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP) = 3 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(0)=[], msg_controllen=48, {cmsg_len=48, cmsg_level=0x84 /* SOL_??? */, cmsg_type=, ...}, msg_flags=0}, 0) = 0 // graceful shutdown for SOCK_SEQPACKET via SCTP_EOF close(3) = 0 tcpdump before patch (fooling the application): 22:33:36.306142 IP 192.168.1.114.41462 > 192.168.1.115.8888: sctp (1) [INIT] [init tag: 3879023686] [rwnd: 106496] [OS: 10] [MIS: 65535] [init TSN: 3139201684] 22:33:36.316619 IP 192.168.1.115.8888 > 192.168.1.114.41462: sctp (1) [INIT ACK] [init tag: 3345394793] [rwnd: 106496] [OS: 10] [MIS: 10] [init TSN: 3380109591] 22:33:36.317600 IP 192.168.1.114.41462 > 192.168.1.115.8888: sctp (1) [ABORT] tcpdump after patch: 14:28:58.884116 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [INIT] [init tag: 438593213] [rwnd: 106496] [OS: 10] [MIS: 65535] [init TSN: 3092969729] 14:28:58.888414 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [INIT ACK] [init tag: 381429855] [rwnd: 106496] [OS: 10] [MIS: 10] [init TSN: 2141904492] 14:28:58.888638 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [COOKIE ECHO] , (2) [DATA] (B)(E) [TSN: 3092969729] [...] 14:28:58.893278 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [COOKIE ACK] , (2) [SACK] [cum ack 3092969729] [a_rwnd 106491] [#gap acks 0] [#dup tsns 0] 14:28:58.893591 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [DATA] (B)(E) [TSN: 3092969730] [...] 14:28:59.096963 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SACK] [cum ack 3092969730] [a_rwnd 106496] [#gap acks 0] [#dup tsns 0] 14:28:59.097086 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [DATA] (B)(E) [TSN: 3092969731] [...] , (2) [DATA] (B)(E) [TSN: 3092969732] [...] 14:28:59.103218 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SACK] [cum ack 3092969732] [a_rwnd 106486] [#gap acks 0] [#dup tsns 0] 14:28:59.103330 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [SHUTDOWN] 14:28:59.107793 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SHUTDOWN ACK] 14:28:59.107890 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [SHUTDOWN COMPLETE] Looks like this bug is from the pre-git history museum. ;) Fixes: 08707d5482df ("lksctp-2_5_31-0_5_1.patch") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-11net: introduce helper macro for_each_cmsghdrGu Zheng1-2/+1
Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating cmsghdr from msghdr, just cleanup. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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