kernel/linux.git/include/net/sock.h, branch v4.14.18

net: remove hlist_nulls_add_tail_rcu()

2017-12-17T14:07:57+00:00

[ Upstream commit d7efc6c11b277d9d80b99b1334a78bfe7d7edf10 ] Alexander Potapenko reported use of uninitialized memory [1] This happens when inserting a request socket into TCP ehash, in __sk_nulls_add_node_rcu(), since sk_reuseport is not initialized. Bug was added by commit d894ba18d4e4 ("soreuseport: fix ordering for mixed v4/v6 sockets") Note that d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix") missed the opportunity to get rid of hlist_nulls_add_tail_rcu() : Both UDP sockets and TCP/DCCP listeners no longer use __sk_nulls_add_node_rcu() for their hash insertion. Since all other sockets have unique 4-tuple, the reuseport status has no special meaning, so we can always use hlist_nulls_add_head_rcu() for them and save few cycles/instructions. [1] ================================================================== BUG: KMSAN: use of uninitialized memory in inet_ehash_insert+0xd40/0x1050 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0+ #3288 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x185/0x1d0 lib/dump_stack.c:52 kmsan_report+0x13f/0x1c0 mm/kmsan/kmsan.c:1016 __msan_warning_32+0x69/0xb0 mm/kmsan/kmsan_instr.c:766 __sk_nulls_add_node_rcu ./include/net/sock.h:684 inet_ehash_insert+0xd40/0x1050 net/ipv4/inet_hashtables.c:413 reqsk_queue_hash_req net/ipv4/inet_connection_sock.c:754 inet_csk_reqsk_queue_hash_add+0x1cc/0x300 net/ipv4/inet_connection_sock.c:765 tcp_conn_request+0x31e7/0x36f0 net/ipv4/tcp_input.c:6414 tcp_v4_conn_request+0x16d/0x220 net/ipv4/tcp_ipv4.c:1314 tcp_rcv_state_process+0x42a/0x7210 net/ipv4/tcp_input.c:5917 tcp_v4_do_rcv+0xa6a/0xcd0 net/ipv4/tcp_ipv4.c:1483 tcp_v4_rcv+0x3de0/0x4ab0 net/ipv4/tcp_ipv4.c:1763 ip_local_deliver_finish+0x6bb/0xcb0 net/ipv4/ip_input.c:216 NF_HOOK ./include/linux/netfilter.h:248 ip_local_deliver+0x3fa/0x480 net/ipv4/ip_input.c:257 dst_input ./include/net/dst.h:477 ip_rcv_finish+0x6fb/0x1540 net/ipv4/ip_input.c:397 NF_HOOK ./include/linux/netfilter.h:248 ip_rcv+0x10f6/0x15c0 net/ipv4/ip_input.c:488 __netif_receive_skb_core+0x36f6/0x3f60 net/core/dev.c:4298 __netif_receive_skb net/core/dev.c:4336 netif_receive_skb_internal+0x63c/0x19c0 net/core/dev.c:4497 napi_skb_finish net/core/dev.c:4858 napi_gro_receive+0x629/0xa50 net/core/dev.c:4889 e1000_receive_skb drivers/net/ethernet/intel/e1000/e1000_main.c:4018 e1000_clean_rx_irq+0x1492/0x1d30 drivers/net/ethernet/intel/e1000/e1000_main.c:4474 e1000_clean+0x43aa/0x5970 drivers/net/ethernet/intel/e1000/e1000_main.c:3819 napi_poll net/core/dev.c:5500 net_rx_action+0x73c/0x1820 net/core/dev.c:5566 __do_softirq+0x4b4/0x8dd kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 irq_exit+0x203/0x240 kernel/softirq.c:405 exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:638 do_IRQ+0x15e/0x1a0 arch/x86/kernel/irq.c:263 common_interrupt+0x86/0x86 Fixes: d894ba18d4e4 ("soreuseport: fix ordering for mixed v4/v6 sockets") Fixes: d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix") Signed-off-by: Eric Dumazet Reported-by: Alexander Potapenko Acked-by: Craig Gallek Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: prevent dst uses after free

2017-09-22T03:42:15+00:00

In linux-4.13, Wei worked hard to convert dst to a traditional refcounted model, removing GC. We now want to make sure a dst refcount can not transition from 0 back to 1. The problem here is that input path attached a not refcounted dst to an skb. Then later, because packet is forwarded and hits skb_dst_force() before exiting RCU section, we might try to take a refcount on one dst that is about to be freed, if another cpu saw 1 -> 0 transition in dst_release() and queued the dst for freeing after one RCU grace period. Lets unify skb_dst_force() and skb_dst_force_safe(), since we should always perform the complete check against dst refcount, and not assume it is not zero. Bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=197005 [ 989.919496] skb_dst_force+0x32/0x34 [ 989.919498] __dev_queue_xmit+0x1ad/0x482 [ 989.919501] ? eth_header+0x28/0xc6 [ 989.919502] dev_queue_xmit+0xb/0xd [ 989.919504] neigh_connected_output+0x9b/0xb4 [ 989.919507] ip_finish_output2+0x234/0x294 [ 989.919509] ? ipt_do_table+0x369/0x388 [ 989.919510] ip_finish_output+0x12c/0x13f [ 989.919512] ip_output+0x53/0x87 [ 989.919513] ip_forward_finish+0x53/0x5a [ 989.919515] ip_forward+0x2cb/0x3e6 [ 989.919516] ? pskb_trim_rcsum.part.9+0x4b/0x4b [ 989.919518] ip_rcv_finish+0x2e2/0x321 [ 989.919519] ip_rcv+0x26f/0x2eb [ 989.919522] ? vlan_do_receive+0x4f/0x289 [ 989.919523] __netif_receive_skb_core+0x467/0x50b [ 989.919526] ? tcp_gro_receive+0x239/0x239 [ 989.919529] ? inet_gro_receive+0x226/0x238 [ 989.919530] __netif_receive_skb+0x4d/0x5f [ 989.919532] netif_receive_skb_internal+0x5c/0xaf [ 989.919533] napi_gro_receive+0x45/0x81 [ 989.919536] ixgbe_poll+0xc8a/0xf09 [ 989.919539] ? kmem_cache_free_bulk+0x1b6/0x1f7 [ 989.919540] net_rx_action+0xf4/0x266 [ 989.919543] __do_softirq+0xa8/0x19d [ 989.919545] irq_exit+0x5d/0x6b [ 989.919546] do_IRQ+0x9c/0xb5 [ 989.919548] common_interrupt+0x93/0x93 [ 989.919548] Similarly dst_clone() can use dst_hold() helper to have additional debugging, as a follow up to commit 44ebe79149ff ("net: add debug atomic_inc_not_zero() in dst_hold()") In net-next we will convert dst atomic_t to refcount_t for peace of mind. Fixes: a4c2fd7f7891 ("net: remove DST_NOCACHE flag") Signed-off-by: Eric Dumazet Cc: Wei Wang Reported-by: Paweł Staszewski Bisected-by: Paweł Staszewski Acked-by: Wei Wang Acked-by: Martin KaFai Lau Signed-off-by: David S. Miller

neigh: increase queue_len_bytes to match wmem_default

2017-08-29T23:10:50+00:00

Florian reported UDP xmit drops that could be root caused to the too small neigh limit. Current limit is 64 KB, meaning that even a single UDP socket would hit it, since its default sk_sndbuf comes from net.core.wmem_default (~212992 bytes on 64bit arches). Once ARP/ND resolution is in progress, we should allow a little more packets to be queued, at least for one producer. Once neigh arp_queue is filled, a rogue socket should hit its sk_sndbuf limit and either block in sendmsg() or return -EAGAIN. Signed-off-by: Eric Dumazet Reported-by: Florian Fainelli Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-08-22T00:06:42+00:00

datagram: When peeking datagrams with offset < 0 don't skip empty skbs

2017-08-18T22:12:54+00:00

Due to commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac ("udp: remove headers from UDP packets before queueing"), when udp packets are being peeked the requested extra offset is always 0 as there is no need to skip the udp header. However, when the offset is 0 and the next skb is of length 0, it is only returned once. The behaviour can be seen with the following python script: from socket import *; f=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0); g=socket(AF_INET6, SOCK_DGRAM | SOCK_NONBLOCK, 0); f.bind(('::', 0)); addr=('::1', f.getsockname()[1]); g.sendto(b'', addr) g.sendto(b'b', addr) print(f.recvfrom(10, MSG_PEEK)); print(f.recvfrom(10, MSG_PEEK)); Where the expected output should be the empty string twice. Instead, make sk_peek_offset return negative values, and pass those values to __skb_try_recv_datagram/__skb_try_recv_from_queue. If the passed offset to __skb_try_recv_from_queue is negative, the checked skb is never skipped. __skb_try_recv_from_queue will then ensure the offset is reset back to 0 if a peek is requested without an offset, unless no packets are found. Also simplify the if condition in __skb_try_recv_from_queue. If _off is greater then 0, and off is greater then or equal to skb->len, then (_off || skb->len) must always be true assuming skb->len >= 0 is always true. Also remove a redundant check around a call to sk_peek_offset in af_unix.c, as it double checked if MSG_PEEK was set in the flags. V2: - Moved the negative fixup into __skb_try_recv_from_queue, and remove now redundant checks - Fix peeking in udp{,v6}_recvmsg to report the right value when the offset is 0 V3: - Marked new branch in __skb_try_recv_from_queue as unlikely. Signed-off-by: Matthew Dawson Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

sock: add MSG_ZEROCOPY

2017-08-04T04:37:29+00:00

The kernel supports zerocopy sendmsg in virtio and tap. Expand the infrastructure to support other socket types. Introduce a completion notification channel over the socket error queue. Notifications are returned with ee_origin SO_EE_ORIGIN_ZEROCOPY. ee_errno is 0 to avoid blocking the send/recv path on receiving notifications. Add reference counting, to support the skb split, merge, resize and clone operations possible with SOCK_STREAM and other socket types. The patch does not yet modify any datapaths. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

sock: allocate skbs from optmem

2017-08-04T04:37:29+00:00

Add sock_omalloc and sock_ofree to be able to allocate control skbs, for instance for looping errors onto sk_error_queue. The transmit budget (sk_wmem_alloc) is involved in transmit skb shaping, most notably in TCP Small Queues. Using this budget for control packets would impact transmission. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

proto_ops: Add locked held versions of sendmsg and sendpage

2017-08-01T22:26:18+00:00

Add new proto_ops sendmsg_locked and sendpage_locked that can be called when the socket lock is already held. Correspondingly, add kernel_sendmsg_locked and kernel_sendpage_locked as front end functions. These functions will be used in zero proxy so that we can take the socket lock in a ULP sendmsg/sendpage and then directly call the backend transport proto_ops functions. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

Merge tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2017-07-19T15:55:18+00:00

Pull structure randomization updates from Kees Cook: "Now that IPC and other changes have landed, enable manual markings for randstruct plugin, including the task_struct. This is the rest of what was staged in -next for the gcc-plugins, and comes in three patches, largest first: - mark "easy" structs with __randomize_layout - mark task_struct with an optional anonymous struct to isolate the __randomize_layout section - mark structs to opt _out_ of automated marking (which will come later) And, FWIW, this continues to pass allmodconfig (normal and patched to enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and s390 for me" * tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: opt-out externally exposed function pointer structs task_struct: Allow randomized layout randstruct: Mark various structs for randomization

socket: add documentation for missing elements

2017-07-12T21:39:43+00:00

Fill in missing kernel-doc for missing elements in struct sock. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller