linux-toradex.git/include/linux/skmsg.h, branch v6.0-rc1

net: fix refcount bug in sk_psock_get (2)

2022-08-11T04:47:58+00:00

Syzkaller reports refcount bug as follows:
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 3605 at lib/refcount.c:19 refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19
Modules linked in:
CPU: 1 PID: 3605 Comm: syz-executor208 Not tainted 5.18.0-syzkaller-03023-g7e062cda7d90 #0
 
 __refcount_add_not_zero include/linux/refcount.h:163 [inline]
 __refcount_inc_not_zero include/linux/refcount.h:227 [inline]
 refcount_inc_not_zero include/linux/refcount.h:245 [inline]
 sk_psock_get+0x3bc/0x410 include/linux/skmsg.h:439
 tls_data_ready+0x6d/0x1b0 net/tls/tls_sw.c:2091
 tcp_data_ready+0x106/0x520 net/ipv4/tcp_input.c:4983
 tcp_data_queue+0x25f2/0x4c90 net/ipv4/tcp_input.c:5057
 tcp_rcv_state_process+0x1774/0x4e80 net/ipv4/tcp_input.c:6659
 tcp_v4_do_rcv+0x339/0x980 net/ipv4/tcp_ipv4.c:1682
 sk_backlog_rcv include/net/sock.h:1061 [inline]
 __release_sock+0x134/0x3b0 net/core/sock.c:2849
 release_sock+0x54/0x1b0 net/core/sock.c:3404
 inet_shutdown+0x1e0/0x430 net/ipv4/af_inet.c:909
 __sys_shutdown_sock net/socket.c:2331 [inline]
 __sys_shutdown_sock net/socket.c:2325 [inline]
 __sys_shutdown+0xf1/0x1b0 net/socket.c:2343
 __do_sys_shutdown net/socket.c:2351 [inline]
 __se_sys_shutdown net/socket.c:2349 [inline]
 __x64_sys_shutdown+0x50/0x70 net/socket.c:2349
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
 

During SMC fallback process in connect syscall, kernel will
replaces TCP with SMC. In order to forward wakeup
smc socket waitqueue after fallback, kernel will sets
clcsk->sk_user_data to origin smc socket in
smc_fback_replace_callbacks().

Later, in shutdown syscall, kernel will calls
sk_psock_get(), which treats the clcsk->sk_user_data
as psock type, triggering the refcnt warning.

So, the root cause is that smc and psock, both will use
sk_user_data field. So they will mismatch this field
easily.

This patch solves it by using another bit(defined as
SK_USER_DATA_PSOCK) in PTRMASK, to mark whether
sk_user_data points to a psock object or not.
This patch depends on a PTRMASK introduced in commit f1ff5ce2cd5e
("net, sk_msg: Clear sk_user_data pointer on clone if tagged").

For there will possibly be more flags in the sk_user_data field,
this patch also refactor sk_user_data flags code to be more generic
to improve its maintainability.

Reported-and-tested-by: syzbot+5f26f85569bd179c18ce@syzkaller.appspotmail.com
Suggested-by: Jakub Kicinski 
Acked-by: Wen Gu 
Signed-off-by: Hawkins Jiawei 
Reviewed-by: Jakub Sitnicki 
Signed-off-by: Jakub Kicinski

bpf, sockmap: Fix sk->sk_forward_alloc warn_on in sk_stream_kill_queues

2022-06-02T23:26:58+00:00

During TCP sockmap redirect pressure test, the following warning is triggered:

WARNING: CPU: 3 PID: 2145 at net/core/stream.c:205 sk_stream_kill_queues+0xbc/0xd0
CPU: 3 PID: 2145 Comm: iperf Kdump: loaded Tainted: G        W         5.10.0+ #9
Call Trace:
 inet_csk_destroy_sock+0x55/0x110
 inet_csk_listen_stop+0xbb/0x380
 tcp_close+0x41b/0x480
 inet_release+0x42/0x80
 __sock_release+0x3d/0xa0
 sock_close+0x11/0x20
 __fput+0x9d/0x240
 task_work_run+0x62/0x90
 exit_to_user_mode_prepare+0x110/0x120
 syscall_exit_to_user_mode+0x27/0x190
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The reason we observed is that:

When the listener is closing, a connection may have completed the three-way
handshake but not accepted, and the client has sent some packets. The child
sks in accept queue release by inet_child_forget()->inet_csk_destroy_sock(),
but psocks of child sks have not released.

To fix, add sock_map_destroy to release psocks.

Signed-off-by: Wang Yufen 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Andrii Nakryiko 
Acked-by: Jakub Sitnicki 
Acked-by: John Fastabend 
Link: https://lore.kernel.org/bpf/20220524075311.649153-1-wangyufen@huawei.com

bpf, sockmap: Fix memleak in sk_psock_queue_msg

2022-03-15T15:43:31+00:00

If tcp_bpf_sendmsg is running during a tear down operation we may enqueue
data on the ingress msg queue while tear down is trying to free it.

 sk1 (redirect sk2)                         sk2
 -------------------                      ---------------
tcp_bpf_sendmsg()
 tcp_bpf_send_verdict()
  tcp_bpf_sendmsg_redir()
   bpf_tcp_ingress()
                                          sock_map_close()
                                           lock_sock()
    lock_sock() ... blocking
                                           sk_psock_stop
                                            sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
                                           release_sock(sk);
    lock_sock()
    sk_mem_charge()
    get_page()
    sk_psock_queue_msg()
     sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED);
      drop_sk_msg()
    release_sock()

While drop_sk_msg(), the msg has charged memory form sk by sk_mem_charge
and has sg pages need to put. To fix we use sk_msg_free() and then kfee()
msg.

This issue can cause the following info:
WARNING: CPU: 0 PID: 9202 at net/core/stream.c:205 sk_stream_kill_queues+0xc8/0xe0
Call Trace:
 
 inet_csk_destroy_sock+0x55/0x110
 tcp_rcv_state_process+0xe5f/0xe90
 ? sk_filter_trim_cap+0x10d/0x230
 ? tcp_v4_do_rcv+0x161/0x250
 tcp_v4_do_rcv+0x161/0x250
 tcp_v4_rcv+0xc3a/0xce0
 ip_protocol_deliver_rcu+0x3d/0x230
 ip_local_deliver_finish+0x54/0x60
 ip_local_deliver+0xfd/0x110
 ? ip_protocol_deliver_rcu+0x230/0x230
 ip_rcv+0xd6/0x100
 ? ip_local_deliver+0x110/0x110
 __netif_receive_skb_one_core+0x85/0xa0
 process_backlog+0xa4/0x160
 __napi_poll+0x29/0x1b0
 net_rx_action+0x287/0x300
 __do_softirq+0xff/0x2fc
 do_softirq+0x79/0x90
 

WARNING: CPU: 0 PID: 531 at net/ipv4/af_inet.c:154 inet_sock_destruct+0x175/0x1b0
Call Trace:
 
 __sk_destruct+0x24/0x1f0
 sk_psock_destroy+0x19b/0x1c0
 process_one_work+0x1b3/0x3c0
 ? process_one_work+0x3c0/0x3c0
 worker_thread+0x30/0x350
 ? process_one_work+0x3c0/0x3c0
 kthread+0xe6/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x22/0x30
 

Fixes: 9635720b7c88 ("bpf, sockmap: Fix memleak on ingress msg enqueue")
Signed-off-by: Wang Yufen 
Signed-off-by: Daniel Borkmann 
Acked-by: John Fastabend 
Link: https://lore.kernel.org/bpf/20220304081145.2037182-2-wangyufen@huawei.com

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

2022-02-10T02:40:56+00:00

Daniel Borkmann says:

====================
pull-request: bpf-next 2022-02-09

We've added 126 non-merge commits during the last 16 day(s) which contain
a total of 201 files changed, 4049 insertions(+), 2215 deletions(-).

The main changes are:

1) Add custom BPF allocator for JITs that pack multiple programs into a huge
   page to reduce iTLB pressure, from Song Liu.

2) Add __user tagging support in vmlinux BTF and utilize it from BPF
   verifier when generating loads, from Yonghong Song.

3) Add per-socket fast path check guarding from cgroup/BPF overhead when
   used by only some sockets, from Pavel Begunkov.

4) Continued libbpf deprecation work of APIs/features and removal of their
   usage from samples, selftests, libbpf & bpftool, from Andrii Nakryiko
   and various others.

5) Improve BPF instruction set documentation by adding byte swap
   instructions and cleaning up load/store section, from Christoph Hellwig.

6) Switch BPF preload infra to light skeleton and remove libbpf dependency
   from it, from Alexei Starovoitov.

7) Fix architecture-agnostic macros in libbpf for accessing syscall
   arguments from BPF progs for non-x86 architectures,
   from Ilya Leoshkevich.

8) Rework port members in struct bpf_sk_lookup and struct bpf_sock to be
   of 16-bit field with anonymous zero padding, from Jakub Sitnicki.

9) Add new bpf_copy_from_user_task() helper to read memory from a different
   task than current. Add ability to create sleepable BPF iterator progs,
   from Kenny Yu.

10) Implement XSK batching for ice's zero-copy driver used by AF_XDP and
    utilize TX batching API from XSK buffer pool, from Maciej Fijalkowski.

11) Generate temporary netns names for BPF selftests to avoid naming
    collisions, from Hangbin Liu.

12) Implement bpf_core_types_are_compat() with limited recursion for
    in-kernel usage, from Matteo Croce.

13) Simplify pahole version detection and finally enable CONFIG_DEBUG_INFO_DWARF5
    to be selected with CONFIG_DEBUG_INFO_BTF, from Nathan Chancellor.

14) Misc minor fixes to libbpf and selftests from various folks.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (126 commits)
  selftests/bpf: Cover 4-byte load from remote_port in bpf_sk_lookup
  bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide
  libbpf: Fix compilation warning due to mismatched printf format
  selftests/bpf: Test BPF_KPROBE_SYSCALL macro
  libbpf: Add BPF_KPROBE_SYSCALL macro
  libbpf: Fix accessing the first syscall argument on s390
  libbpf: Fix accessing the first syscall argument on arm64
  libbpf: Allow overriding PT_REGS_PARM1{_CORE}_SYSCALL
  selftests/bpf: Skip test_bpf_syscall_macro's syscall_arg1 on arm64 and s390
  libbpf: Fix accessing syscall arguments on riscv
  libbpf: Fix riscv register names
  libbpf: Fix accessing syscall arguments on powerpc
  selftests/bpf: Use PT_REGS_SYSCALL_REGS in bpf_syscall_macro
  libbpf: Add PT_REGS_SYSCALL_REGS macro
  selftests/bpf: Fix an endianness issue in bpf_syscall_macro test
  bpf: Fix bpf_prog_pack build HPAGE_PMD_SIZE
  bpf: Fix leftover header->pages in sparc and powerpc code.
  libbpf: Fix signedness bug in btf_dump_array_data()
  selftests/bpf: Do not export subtest as standalone test
  bpf, x86_64: Fail gracefully on bpf_jit_binary_pack_finalize failures
  ...
====================

Link: https://lore.kernel.org/r/20220209210050.8425-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski

skmsg: convert struct sk_msg_sg::copy to a bitmap

2022-02-05T15:34:47+00:00

We have plans for increasing MAX_SKB_FRAGS, but sk_msg_sg::copy
is currently an unsigned long, limiting MAX_SKB_FRAGS to 30 on 32bit arches.

Convert it to a bitmap, as Jakub suggested.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

bpf: remove unused static inlines

2022-01-27T05:17:53+00:00

Remove two dead stubs, sk_msg_clear_meta() was never
used, use of xskq_cons_is_full() got replaced by
xsk_tx_writeable() in v5.10.

Signed-off-by: Jakub Kicinski 
Link: https://lore.kernel.org/r/20220126185412.2776254-1-kuba@kernel.org
Signed-off-by: Alexei Starovoitov

net: use sk_is_tcp() in more places

2021-11-16T13:10:34+00:00

Move sk_is_tcp() to include/net/sock.h and use it where we can.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

bpf, sockmap: Use stricter sk state checks in sk_lookup_assign

2021-11-08T23:56:35+00:00

In order to fix an issue with sockets in TCP sockmap redirect cases we plan
to allow CLOSE state sockets to exist in the sockmap. However, the check in
bpf_sk_lookup_assign() currently only invalidates sockets in the
TCP_ESTABLISHED case relying on the checks on sockmap insert to ensure we
never SOCK_CLOSE state sockets in the map.

To prepare for this change we flip the logic in bpf_sk_lookup_assign() to
explicitly test for the accepted cases. Namely, a tcp socket in TCP_LISTEN
or a udp socket in TCP_CLOSE state. This also makes the code more resilent
to future changes.

Suggested-by: Jakub Sitnicki 
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20211103204736.248403-2-john.fastabend@gmail.com

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

2021-11-02T02:59:46+00:00

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
  libbpf: Deprecate AF_XDP support
  kbuild: Unify options for BTF generation for vmlinux and modules
  selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
  bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
  bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
  selftests/bpf: Fix also no-alu32 strobemeta selftest
  bpf: Add missing map_delete_elem method to bloom filter map
  selftests/bpf: Add bloom map success test for userspace calls
  bpf: Add alignment padding for "map_extra" + consolidate holes
  bpf: Bloom filter map naming fixups
  selftests/bpf: Add test cases for struct_ops prog
  bpf: Add dummy BPF STRUCT_OPS for test purpose
  bpf: Factor out helpers for ctx access checking
  bpf: Factor out a helper to prepare trampoline for struct_ops prog
  selftests, bpf: Fix broken riscv build
  riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
  tools, build: Add RISC-V to HOSTARCH parsing
  riscv, bpf: Increase the maximum number of iterations
  selftests, bpf: Add one test for sockmap with strparser
  selftests, bpf: Fix test_txmsg_ingress_parser error
  ...
====================

Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski

skmsg: Lose offset info in sk_psock_skb_ingress

2021-11-01T16:08:21+00:00

If sockmap enable strparser, there are lose offset info in
sk_psock_skb_ingress(). If the length determined by parse_msg function is not
skb->len, the skb will be converted to sk_msg multiple times, and userspace
app will get the data multiple times.

Fix this by get the offset and length from strp_msg. And as Cong suggested,
add one bit in skb->_sk_redir to distinguish enable or disable strparser.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Liu Jian 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Cong Wang 
Acked-by: John Fastabend 
Link: https://lore.kernel.org/bpf/20211029141216.211899-1-liujian56@huawei.com