kernel/linux.git/include/net/sock.h, branch v5.4.146

inet: annotate date races around sk->sk_txhash

2021-06-30T12:47:47+00:00

[ Upstream commit b71eaed8c04f72a919a9c44e83e4ee254e69e7f3 ] UDP sendmsg() path can be lockless, it is possible for another thread to re-connect an change sk->sk_txhash under us. There is no serious impact, but we can use READ_ONCE()/WRITE_ONCE() pair to document the race. BUG: KCSAN: data-race in __ip4_datagram_connect / skb_set_owner_w write to 0xffff88813397920c of 4 bytes by task 30997 on cpu 1: sk_set_txhash include/net/sock.h:1937 [inline] __ip4_datagram_connect+0x69e/0x710 net/ipv4/datagram.c:75 __ip6_datagram_connect+0x551/0x840 net/ipv6/datagram.c:189 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272 inet_dgram_connect+0xfd/0x180 net/ipv4/af_inet.c:580 __sys_connect_file net/socket.c:1837 [inline] __sys_connect+0x245/0x280 net/socket.c:1854 __do_sys_connect net/socket.c:1864 [inline] __se_sys_connect net/socket.c:1861 [inline] __x64_sys_connect+0x3d/0x50 net/socket.c:1861 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88813397920c of 4 bytes by task 31039 on cpu 0: skb_set_hash_from_sk include/net/sock.h:2211 [inline] skb_set_owner_w+0x118/0x220 net/core/sock.c:2101 sock_alloc_send_pskb+0x452/0x4e0 net/core/sock.c:2359 sock_alloc_send_skb+0x2d/0x40 net/core/sock.c:2373 __ip6_append_data+0x1743/0x21a0 net/ipv6/ip6_output.c:1621 ip6_make_skb+0x258/0x420 net/ipv6/ip6_output.c:1983 udpv6_sendmsg+0x160a/0x16b0 net/ipv6/udp.c:1527 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490 __do_sys_sendmmsg net/socket.c:2519 [inline] __se_sys_sendmmsg net/socket.c:2516 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xbca3c43d -> 0xfdb309e0 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 31039 Comm: syz-executor.2 Not tainted 5.13.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: really orphan skbs tied to closing sk

2021-06-03T06:59:13+00:00

[ Upstream commit 098116e7e640ba677d9e345cbee83d253c13d556 ] If the owing socket is shutting down - e.g. the sock reference count already dropped to 0 and only sk_wmem_alloc is keeping the sock alive, skb_orphan_partial() becomes a no-op. When forwarding packets over veth with GRO enabled, the above causes refcount errors. This change addresses the issue with a plain skb_orphan() call in the critical scenario. Fixes: 9adc89af724f ("net: let skb_orphan_partial wake-up waiters.") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: let skb_orphan_partial wake-up waiters.

2021-04-14T06:24:12+00:00

commit 9adc89af724f12a03b47099cd943ed54e877cd59 upstream. Currently the mentioned helper can end-up freeing the socket wmem without waking-up any processes waiting for more write memory. If the partially orphaned skb is attached to an UDP (or raw) socket, the lack of wake-up can hang the user-space. Even for TCP sockets not calling the sk destructor could have bad effects on TSQ. Address the issue using skb_orphan to release the sk wmem before setting the new sock_efree destructor. Additionally bundle the whole ownership update in a new helper, so that later other potential users could avoid duplicate code. v1 -> v2: - use skb_orphan() instead of sort of open coding it (Eric) - provide an helper for the ownership change (Eric) Fixes: f6ba8d33cfbb ("netem: fix skb_orphan_partial()") Suggested-by: Eric Dumazet Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: silence data-races on sk_backlog.tail

2020-10-01T11:17:15+00:00

[ Upstream commit 9ed498c6280a2f2b51d02df96df53037272ede49 ] sk->sk_backlog.tail might be read without holding the socket spinlock, we need to add proper READ_ONCE()/WRITE_ONCE() to silence the warnings. KCSAN reported : BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg write to 0xffff8881265109f8 of 8 bytes by interrupt on cpu 1: __sk_add_backlog include/net/sock.h:907 [inline] sk_add_backlog include/net/sock.h:938 [inline] tcp_add_backlog+0x476/0xce0 net/ipv4/tcp_ipv4.c:1759 tcp_v4_rcv+0x1a70/0x1bd0 net/ipv4/tcp_ipv4.c:1947 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:4929 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5043 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5133 napi_skb_finish net/core/dev.c:5596 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5629 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6311 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6379 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] do_IRQ+0xa6/0x180 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x19 native_safe_halt+0xe/0x10 arch/x86/kernel/paravirt.c:71 arch_cpu_idle+0x1f/0x30 arch/x86/kernel/process.c:571 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1af/0x280 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 start_secondary+0x208/0x260 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 read to 0xffff8881265109f8 of 8 bytes by task 8057 on cpu 0: tcp_recvmsg+0x46e/0x1b40 net/ipv4/tcp.c:2050 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1889 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x4c/0x60 fs/read_write.c:595 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8057 Comm: syz-fuzzer Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net/compat: Add missing sock updates for SCM_RIGHTS

2020-08-21T11:05:25+00:00

commit d9539752d23283db4692384a634034f451261e29 upstream. Add missed sock updates to compat path via a new helper, which will be used more in coming patches. (The net/core/scm.c code is left as-is here to assist with -stable backports for the compat path.) Cc: Christoph Hellwig Cc: Sargun Dhillon Cc: Jakub Kicinski Cc: stable@vger.kernel.org Fixes: 48a87cc26c13 ("net: netprio: fd passed in SCM_RIGHTS datagram not set correctly") Fixes: d84295067fc7 ("net: net_cls: fd passed in SCM_RIGHTS datagram not set correctly") Acked-by: Christian Brauner Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman

net: Do not clear the sock TX queue in sk_set_socket()

2020-06-30T19:36:44+00:00

[ Upstream commit 41b14fb8724d5a4b382a63cb4a1a61880347ccb8 ] Clearing the sock TX queue in sk_set_socket() might cause unexpected out-of-order transmit when called from sock_orphan(), as outstanding packets can pick a different TX queue and bypass the ones already queued. This is undesired in general. More specifically, it breaks the in-order scheduling property guarantee for device-offloaded TLS sockets. Remove the call to sk_tx_queue_clear() in sk_set_socket(), and add it explicitly only where needed. Fixes: e022f0b4a03f ("net: Introduce sk_tx_queue_mapping") Signed-off-by: Tariq Toukan Reviewed-by: Boris Pismenny Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: annotate lockless accesses to sk->sk_pacing_shift

2020-01-09T09:20:07+00:00

[ Upstream commit 7c68fa2bddda6d942bd387c9ba5b4300737fd991 ] sk->sk_pacing_shift can be read and written without lock synchronization. This patch adds annotations to document this fact and avoid future syzbot complains. This might also avoid unexpected false sharing in sk_pacing_shift_update(), as the compiler could remove the conditional check and always write over sk->sk_pacing_shift : if (sk->sk_pacing_shift != val) sk->sk_pacing_shift = val; Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

tcp/dccp: fix possible race __inet_lookup_established()

2020-01-04T18:19:13+00:00

[ Upstream commit 8dbd76e79a16b45b2ccb01d2f2e08dbf64e71e40 ] Michal Kubecek and Firo Yang did a very nice analysis of crashes happening in __inet_lookup_established(). Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN (via a close()/socket()/listen() cycle) without a RCU grace period, I should not have changed listeners linkage in their hash table. They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt), so that a lookup can detect a socket in a hash list was moved in another one. Since we added code in commit d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix"), we have to add hlist_nulls_add_tail_rcu() helper. Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood") Signed-off-by: Eric Dumazet Reported-by: Michal Kubecek Reported-by: Firo Yang Reviewed-by: Michal Kubecek Link: https://lore.kernel.org/netdev/20191120083919.GH27852@unicorn.suse.cz/ Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: avoid potential false sharing in neighbor related code

2019-12-31T15:45:03+00:00

[ Upstream commit 25c7a6d1f90e208ec27ca854b1381ed39842ec57 ] There are common instances of the following construct : if (n->confirmed != now) n->confirmed = now; A C compiler could legally remove the conditional. Use READ_ONCE()/WRITE_ONCE() to avoid this problem. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: prevent load/store tearing on sk->sk_stamp

2019-11-06T02:22:30+00:00

Add a couple of READ_ONCE() and WRITE_ONCE() to prevent load-tearing and store-tearing in sock_read_timestamp() and sock_write_timestamp() This might prevent another KCSAN report. Fixes: 3a0ed3e96197 ("sock: Make sock->sk_stamp thread-safe") Signed-off-by: Eric Dumazet Cc: Deepa Dinamani Acked-by: Deepa Dinamani Signed-off-by: David S. Miller