user/sven/linux.git/net/sctp, branch v4.20

sctp: initialize sin6_flowinfo for ipv6 addrs in sctp_inet6addr_event

2018-12-10T19:53:42Z

syzbot reported a kernel-infoleak, which is caused by an uninitialized field(sin6_flowinfo) of addr->a.v6 in sctp_inet6addr_event(). The call trace is as below: BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 lib/usercopy.c:33 CPU: 1 PID: 8164 Comm: syz-executor2 Not tainted 4.20.0-rc3+ #95 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x32d/0x480 lib/dump_stack.c:113 kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683 kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743 kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634 _copy_to_user+0x19a/0x230 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:183 [inline] sctp_getsockopt_local_addrs net/sctp/socket.c:5998 [inline] sctp_getsockopt+0x15248/0x186f0 net/sctp/socket.c:7477 sock_common_getsockopt+0x13f/0x180 net/core/sock.c:2937 __sys_getsockopt+0x489/0x550 net/socket.c:1939 __do_sys_getsockopt net/socket.c:1950 [inline] __se_sys_getsockopt+0xe1/0x100 net/socket.c:1947 __x64_sys_getsockopt+0x62/0x80 net/socket.c:1947 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 sin6_flowinfo is not really used by SCTP, so it will be fixed by simply setting it to 0. The issue exists since very beginning. Thanks Alexander for the reproducer provided. Reported-by: syzbot+ad5d327e6936a2e284be@syzkaller.appspotmail.com Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: frag_point sanity check

2018-12-06T04:37:52Z

If for some reason an association's fragmentation point is zero, sctp_datamsg_from_user will try to endlessly try to divide a message into zero-sized chunks. This eventually causes kernel panic due to running out of memory. Although this situation is quite unlikely, it has occurred before as reported. I propose to add this simple last-ditch sanity check due to the severity of the potential consequences. Signed-off-by: Jakub Audykowicz Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: kfree_rcu asoc

2018-12-03T23:54:41Z

In sctp_hash_transport/sctp_epaddr_lookup_transport, it dereferences a transport's asoc under rcu_read_lock while asoc is freed not after a grace period, which leads to a use-after-free panic. This patch fixes it by calling kfree_rcu to make asoc be freed after a grace period. Note that only the asoc's memory is delayed to free in the patch, it won't cause sk to linger longer. Thanks Neil and Marcelo to make this clear. Fixes: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable") Fixes: cd2b70875058 ("sctp: check duplicate node before inserting a new transport") Reported-by: syzbot+0b05d8aa7cb185107483@syzkaller.appspotmail.com Reported-by: syzbot+aad231d51b1923158444@syzkaller.appspotmail.com Suggested-by: Neil Horman Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: update frag_point when stream_interleave is set

2018-11-30T21:12:43Z

sctp_assoc_update_frag_point() should be called whenever asoc->pathmtu changes, but we missed one place in sctp_association_init(). It would cause frag_point is zero when sending data. As says in Jakub's reproducer, if sp->pathmtu is set by socketopt, the new asoc->pathmtu inherits it in sctp_association_init(). Later when transports are added and their pmtu >= asoc->pathmtu, it will never call sctp_assoc_update_frag_point() to set frag_point. This patch is to fix it by updating frag_point after asoc->pathmtu is set as sp->pathmtu in sctp_association_init(). Note that it moved them after sctp_stream_init(), as stream->si needs to be set first. Frag_point's calculation is also related with datachunk's type, so it needs to update frag_point when stream->si may be changed in sctp_process_init(). v1->v2: - call sctp_assoc_update_frag_point() separately in sctp_process_init and sctp_association_init, per Marcelo's suggestion. Fixes: 2f5e3c9df693 ("sctp: introduce sctp_assoc_update_frag_point") Reported-by: Jakub Audykowicz Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: increase sk_wmem_alloc when head->truesize is increased

2018-11-27T23:42:31Z

I changed to count sk_wmem_alloc by skb truesize instead of 1 to fix the sk_wmem_alloc leak caused by later truesize's change in xfrm in Commit 02968ccf0125 ("sctp: count sk_wmem_alloc by skb truesize in sctp_packet_transmit"). But I should have also increased sk_wmem_alloc when head->truesize is increased in sctp_packet_gso_append() as xfrm does. Otherwise, sctp gso packet will cause sk_wmem_alloc underflow. Fixes: 02968ccf0125 ("sctp: count sk_wmem_alloc by skb truesize in sctp_packet_transmit") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: not increase stream's incnt before sending addstrm_in request

2018-11-19T22:46:32Z

Different from processing the addstrm_out request, The receiver handles an addstrm_in request by sending back an addstrm_out request to the sender who will increase its stream's in and incnt later. Now stream->incnt has been increased since it sent out the addstrm_in request in sctp_send_add_streams(), with the wrong stream->incnt will even cause crash when copying stream info from the old stream's in to the new one's in sctp_process_strreset_addstrm_out(). This patch is to fix it by simply removing the stream->incnt change from sctp_send_add_streams(). Fixes: 242bd2d519d7 ("sctp: implement sender-side procedures for Add Incoming/Outgoing Streams Request Parameter") Reported-by: Jianwen Ji Signed-off-by: Xin Long Signed-off-by: David S. Miller

Revert "sctp: remove sctp_transport_pmtu_check"

2018-11-19T20:42:47Z

This reverts commit 22d7be267eaa8114dcc28d66c1c347f667d7878a. The dst's mtu in transport can be updated by a non sctp place like in xfrm where the MTU information didn't get synced between asoc, transport and dst, so it is still needed to do the pmtu check in sctp_packet_config. Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: not allow to set asoc prsctp_enable by sockopt

2018-11-19T20:41:18Z

As rfc7496#section4.5 says about SCTP_PR_SUPPORTED: This socket option allows the enabling or disabling of the negotiation of PR-SCTP support for future associations. For existing associations, it allows one to query whether or not PR-SCTP support was negotiated on a particular association. It means only sctp sock's prsctp_enable can be set. Note that for the limitation of SCTP_{CURRENT|ALL}_ASSOC, we will add it when introducing SCTP_{FUTURE|CURRENT|ALL}_ASSOC for linux sctp in another patchset. v1->v2: - drop the params.assoc_id check as Neil suggested. Fixes: 28aa4c26fce2 ("sctp: add SCTP_PR_SUPPORTED on sctp sockopt") Reported-by: Ying Xu Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: count sk_wmem_alloc by skb truesize in sctp_packet_transmit

2018-11-19T20:39:05Z

Now sctp increases sk_wmem_alloc by 1 when doing set_owner_w for the skb allocked in sctp_packet_transmit and decreases by 1 when freeing this skb. But when this skb goes through networking stack, some subcomponents might change skb->truesize and add the same amount on sk_wmem_alloc. However sctp doesn't know the amount to decrease by, it would cause a leak on sk->sk_wmem_alloc and the sock can never be freed. Xiumei found this issue when it hit esp_output_head() by using sctp over ipsec, where skb->truesize is added and so is sk->sk_wmem_alloc. Since sctp has used sk_wmem_queued to count for writable space since Commit cd305c74b0f8 ("sctp: use sk_wmem_queued to check for writable space"), it's ok to fix it by counting sk_wmem_alloc by skb truesize in sctp_packet_transmit. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Reported-by: Xiumei Mu Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: define SCTP_SS_DEFAULT for Stream schedulers

2018-11-04T02:40:29Z

According to rfc8260#section-4.3.2, SCTP_SS_DEFAULT is required to defined as SCTP_SS_FCFS or SCTP_SS_RR. SCTP_SS_FCFS is used for SCTP_SS_DEFAULT's value in this patch. Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: Jianwen Ji Signed-off-by: Xin Long Signed-off-by: David S. Miller