kernel/linux.git/include/net/sock.h, branch v5.13.5

inet: annotate date races around sk->sk_txhash

2021-06-10T21:12:54+00:00

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

net: annotate data race in sock_error()

2021-06-10T21:12:54+00:00

sock_error() is known to be racy. The code avoids an atomic operation is sk_err is zero, and this field could be changed under us, this is fine. Sysbot reported: BUG: KCSAN: data-race in sock_alloc_send_pskb / unix_release_sock write to 0xffff888131855630 of 4 bytes by task 9365 on cpu 1: unix_release_sock+0x2e9/0x6e0 net/unix/af_unix.c:550 unix_release+0x2f/0x50 net/unix/af_unix.c:859 __sock_release net/socket.c:599 [inline] sock_close+0x6c/0x150 net/socket.c:1258 __fput+0x25b/0x4e0 fs/file_table.c:280 ____fput+0x11/0x20 fs/file_table.c:313 task_work_run+0xae/0x130 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888131855630 of 4 bytes by task 9385 on cpu 0: sock_error include/net/sock.h:2269 [inline] sock_alloc_send_pskb+0xe4/0x4e0 net/core/sock.c:2336 unix_dgram_sendmsg+0x478/0x1610 net/unix/af_unix.c:1671 unix_seqpacket_sendmsg+0xc2/0x100 net/unix/af_unix.c:2055 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_sock+0x25/0x30 net/socket.c:2416 io_sendmsg fs/io_uring.c:4367 [inline] io_issue_sqe+0x231a/0x6750 fs/io_uring.c:6135 __io_queue_sqe+0xe9/0x360 fs/io_uring.c:6414 __io_req_task_submit fs/io_uring.c:2039 [inline] io_async_task_func+0x312/0x590 fs/io_uring.c:5074 __tctx_task_work fs/io_uring.c:1910 [inline] tctx_task_work+0x1d4/0x3d0 fs/io_uring.c:1924 task_work_run+0xae/0x130 kernel/task_work.c:164 tracehook_notify_signal include/linux/tracehook.h:212 [inline] handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0xf8/0x190 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000000 -> 0x00000068 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 9385 Comm: syz-executor.3 Not tainted 5.13.0-rc4-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

net: really orphan skbs tied to closing sk

2021-05-12T20:48:58+00:00

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

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2021-04-26T01:02:32+00:00

Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-04-23 The following pull-request contains BPF updates for your *net-next* tree. We've added 69 non-merge commits during the last 22 day(s) which contain a total of 69 files changed, 3141 insertions(+), 866 deletions(-). The main changes are: 1) Add BPF static linker support for extern resolution of global, from Andrii. 2) Refine retval for bpf_get_task_stack helper, from Dave. 3) Add a bpf_snprintf helper, from Florent. 4) A bunch of miscellaneous improvements from many developers. ==================== Signed-off-by: David S. Miller

skmsg: Pass psock pointer to ->psock_update_sk_prot()

2021-04-12T15:34:27+00:00

Using sk_psock() to retrieve psock pointer from sock requires RCU read lock, but we already get psock pointer before calling ->psock_update_sk_prot() in both cases, so we can just pass it without bothering sk_psock(). Fixes: 8a59f9d1e3d4 ("sock: Introduce sk->sk_prot->psock_update_sk_prot()") Reported-by: syzbot+320a3bc8d80f478c37e4@syzkaller.appspotmail.com Signed-off-by: Cong Wang Signed-off-by: Daniel Borkmann Tested-by: syzbot+320a3bc8d80f478c37e4@syzkaller.appspotmail.com Reviewed-by: Jakub Sitnicki Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210407032111.33398-1-xiyou.wangcong@gmail.com

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

2021-04-10T03:48:35+00:00

Conflicts: MAINTAINERS - keep Chandrasekar drivers/net/ethernet/mellanox/mlx5/core/en_main.c - simple fix + trust the code re-added to param.c in -next is fine include/linux/bpf.h - trivial include/linux/ethtool.h - trivial, fix kdoc while at it include/linux/skmsg.h - move to relevant place in tcp.c, comment re-wrapped net/core/skmsg.c - add the sk = sk // sk = NULL around calls net/tipc/crypto.c - trivial Signed-off-by: Jakub Kicinski

sock: Introduce sk->sk_prot->psock_update_sk_prot()

2021-04-01T17:56:14+00:00

Currently sockmap calls into each protocol to update the struct proto and replace it. This certainly won't work when the protocol is implemented as a module, for example, AF_UNIX. Introduce a new ops sk->sk_prot->psock_update_sk_prot(), so each protocol can implement its own way to replace the struct proto. This also helps get rid of symbol dependencies on CONFIG_INET. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210331023237.41094-11-xiyou.wangcong@gmail.com

Revert "net: correct sk_acceptq_is_full()"

2021-03-31T21:58:45+00:00

This reverts commit f211ac154577ec9ccf07c15f18a6abf0d9bdb4ab. We had similar attempt in the past, and we reverted it. History: 64a146513f8f12ba204b7bf5cb7e9505594ead42 [NET]: Revert incorrect accept queue backlog changes. 8488df894d05d6fa41c2bd298c335f944bb0e401 [NET]: Fix bugs in "Whether sock accept queue is full" checking I am adding a fat comment so that future attempts will be much harder. Fixes: f211ac154577 ("net: correct sk_acceptq_is_full()") Cc: iuyacan Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: let skb_orphan_partial wake-up waiters.

2021-03-30T20:57:28+00:00

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

net: correct sk_acceptq_is_full()

2021-03-12T20:27:14+00:00

The "backlog" argument in listen() specifies the maximom length of pending connections, so the accept queue should be considered full if there are exactly "backlog" elements. Signed-off-by: liuyacan Signed-off-by: David S. Miller