kernel/linux.git/include/net/sctp/structs.h, branch v5.4.230

sctp: use call_rcu to free endpoint

2022-01-05T11:37:44+00:00

[ Upstream commit 5ec7d18d1813a5bead0b495045606c93873aecbb ] This patch is to delay the endpoint free by calling call_rcu() to fix another use-after-free issue in sctp_sock_dump(): BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20 Call Trace: __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] __lock_sock+0x203/0x350 net/core/sock.c:2253 lock_sock_nested+0xfe/0x120 net/core/sock.c:2774 lock_sock include/net/sock.h:1492 [inline] sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324 sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5091 sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527 __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049 inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065 netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:216 [inline] inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170 __sock_diag_cmd net/core/sock_diag.c:232 [inline] sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274 This issue occurs when asoc is peeled off and the old sk is freed after getting it by asoc->base.sk and before calling lock_sock(sk). To prevent the sk free, as a holder of the sk, ep should be alive when calling lock_sock(). This patch uses call_rcu() and moves sock_put and ep free into sctp_endpoint_destroy_rcu(), so that it's safe to try to hold the ep under rcu_read_lock in sctp_transport_traverse_process(). If sctp_endpoint_hold() returns true, it means this ep is still alive and we have held it and can continue to dump it; If it returns false, it means this ep is dead and can be freed after rcu_read_unlock, and we should skip it. In sctp_sock_dump(), after locking the sk, if this ep is different from tsp->asoc->ep, it means during this dumping, this asoc was peeled off before calling lock_sock(), and the sk should be skipped; If this ep is the same with tsp->asoc->ep, it means no peeloff happens on this asoc, and due to lock_sock, no peeloff will happen either until release_sock. Note that delaying endpoint free won't delay the port release, as the port release happens in sctp_endpoint_destroy() before calling call_rcu(). Also, freeing endpoint by call_rcu() makes it safe to access the sk by asoc->base.sk in sctp_assocs_seq_show() and sctp_rcv(). Thanks Jones to bring this issue up. v1->v2: - improve the changelog. - add kfree(ep) into sctp_endpoint_destroy_rcu(), as Jakub noticed. Reported-by: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com Reported-by: Lee Jones Fixes: d25adbeb0cdb ("sctp: fix an use-after-free issue in sctp_sock_dump") Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

sctp: validate from_addr_param return

2021-07-19T06:53:13+00:00

[ Upstream commit 0c5dc070ff3d6246d22ddd931f23a6266249e3db ] Ilja reported that, simply putting it, nothing was validating that from_addr_param functions were operating on initialized memory. That is, the parameter itself was being validated by sctp_walk_params, but it doesn't check for types and their specific sizes and it could be a 0-length one, causing from_addr_param to potentially work over the next parameter or even uninitialized memory. The fix here is to, in all calls to from_addr_param, check if enough space is there for the wanted IP address type. Reported-by: Ilja Van Sprundel Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: sctp: Fix IPv6 ancestor_size calc in sctp_copy_descendant

2020-09-26T16:03:13+00:00

[ Upstream commit fe81d9f6182d1160e625894eecb3d7ff0222cac5 ] When calculating ancestor_size with IPv6 enabled, simply using sizeof(struct ipv6_pinfo) doesn't account for extra bytes needed for alignment in the struct sctp6_sock. On x86, there aren't any extra bytes, but on ARM the ipv6_pinfo structure is aligned on an 8-byte boundary so there were 4 pad bytes that were omitted from the ancestor_size calculation. This would lead to corruption of the pd_lobby pointers, causing an oops when trying to free the sctp structure on socket close. Fixes: 636d25d557d1 ("sctp: not copy sctp_sock pd_lobby in sctp_copy_descendant") Signed-off-by: Henry Ptasinski Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: cache netns in sctp_ep_common

2019-12-04T21:30:57+00:00

[ Upstream commit 312434617cb16be5166316cf9d08ba760b1042a1 ] This patch is to fix a data-race reported by syzbot: BUG: KCSAN: data-race in sctp_assoc_migrate / sctp_hash_obj write to 0xffff8880b67c0020 of 8 bytes by task 18908 on cpu 1: sctp_assoc_migrate+0x1a6/0x290 net/sctp/associola.c:1091 sctp_sock_migrate+0x8aa/0x9b0 net/sctp/socket.c:9465 sctp_accept+0x3c8/0x470 net/sctp/socket.c:4916 inet_accept+0x7f/0x360 net/ipv4/af_inet.c:734 __sys_accept4+0x224/0x430 net/socket.c:1754 __do_sys_accept net/socket.c:1795 [inline] __se_sys_accept net/socket.c:1792 [inline] __x64_sys_accept+0x4e/0x60 net/socket.c:1792 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880b67c0020 of 8 bytes by task 12003 on cpu 0: sctp_hash_obj+0x4f/0x2d0 net/sctp/input.c:894 rht_key_get_hash include/linux/rhashtable.h:133 [inline] rht_key_hashfn include/linux/rhashtable.h:159 [inline] rht_head_hashfn include/linux/rhashtable.h:174 [inline] head_hashfn lib/rhashtable.c:41 [inline] rhashtable_rehash_one lib/rhashtable.c:245 [inline] rhashtable_rehash_chain lib/rhashtable.c:276 [inline] rhashtable_rehash_table lib/rhashtable.c:316 [inline] rht_deferred_worker+0x468/0xab0 lib/rhashtable.c:420 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 It was caused by rhashtable access asoc->base.sk when sctp_assoc_migrate is changing its value. However, what rhashtable wants is netns from asoc base.sk, and for an asoc, its netns won't change once set. So we can simply fix it by caching netns since created. Fixes: d6c0256a60e6 ("sctp: add the rhashtable apis for sctp global transport hashtable") Reported-by: syzbot+e3b35fe7918ff0ee474e@syzkaller.appspotmail.com Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

sctp: make ecn flag per netns and endpoint

2019-08-28T03:54:14+00:00

This patch is to add ecn flag for both netns_sctp and sctp_endpoint, net->sctp.ecn_enable is set 1 by default, and ep->ecn_enable will be initialized with net->sctp.ecn_enable. asoc->peer.ecn_capable will be set during negotiation only when ep->ecn_enable is set on both sides. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: add asconf_enable in struct sctp_endpoint

2019-08-20T01:27:28+00:00

This patch is to make addip/asconf flag per endpoint, and its value is initialized by the per netns flag, net->sctp.addip_enable. It also replaces the checks of net->sctp.addip_enable with ep->asconf_enable in some places. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: rename sp strm_interleave to ep intl_enable

2019-07-09T03:16:25+00:00

Like other endpoint features, strm_interleave should be moved to sctp_endpoint and renamed to intl_enable. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: rename asoc intl_enable to asoc peer.intl_capable

2019-07-09T03:16:25+00:00

To keep consistent with other asoc features, we move intl_enable to peer.intl_capable in asoc. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove prsctp_enable from asoc

2019-07-09T03:16:24+00:00

Like reconf_enable, prsctp_enable should also be removed from asoc, as asoc->peer.prsctp_capable has taken its job. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: remove reconf_enable from asoc

2019-07-09T03:16:24+00:00

asoc's reconf support is actually decided by the 4-shakehand negotiation, not something that users can set by sockopt. asoc->peer.reconf_capable is working for this. So remove it from asoc. Signed-off-by: Xin Long Signed-off-by: David S. Miller