The commit 314001f0bf ("af_unix: Add OOB support") introduced OOB for
AF_UNIX, but it lacks some changes for POLLPRI. Let's add the missing
piece.
In the selftest, normal datagrams are sent followed by OOB data, so this
commit replaces `POLLIN | POLLPRI` with just `POLLPRI` in the first test
case.
Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Out-of-band data automatically places a "mark" showing wherein the
sequence the out-of-band data would have been. If the out-of-band data
implies cancelling everything sent so far, the "mark" is helpful to flush
them. When the socket's read pointer reaches the "mark", the ioctl() below
sets a non zero value to the arg `atmark`:
The out-of-band data is queued in sk->sk_receive_queue as well as ordinary
data and also saved in unix_sk(sk)->oob_skb. It can be used to test if the
head of the receive queue is the out-of-band data meaning the socket is at
the "mark".
While testing that, unix_ioctl() reads unix_sk(sk)->oob_skb locklessly.
Thus, all accesses to oob_skb need some basic protection to avoid
load/store tearing which KCSAN detects when these are called concurrently:
- ioctl(fd_a, SIOCATMARK, &atmark, sizeof(atmark))
- send(fd_b_connected_to_a, buf, sizeof(buf), MSG_OOB)
BUG: KCSAN: data-race in unix_ioctl / unix_stream_sendmsg
write to 0xffff888003d9cff0 of 8 bytes by task 175 on cpu 1:
unix_stream_sendmsg (net/unix/af_unix.c:2087 net/unix/af_unix.c:2191)
sock_sendmsg (net/socket.c:705 net/socket.c:725)
__sys_sendto (net/socket.c:2040)
__x64_sys_sendto (net/socket.c:2048)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)
read to 0xffff888003d9cff0 of 8 bytes by task 176 on cpu 0:
unix_ioctl (net/unix/af_unix.c:3101 (discriminator 1))
sock_do_ioctl (net/socket.c:1128)
sock_ioctl (net/socket.c:1242)
__x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:874 fs/ioctl.c:860 fs/ioctl.c:860)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)
value changed: 0xffff888003da0c00 -> 0xffff888003da0d00
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 176 Comm: unix_race_oob_i Not tainted 5.17.0-rc5-59529-g83dc4c2af682 #12
Hardware name: Red Hat KVM, BIOS 1.11.0-2.amzn2 04/01/2014
Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-01-24
We've added 80 non-merge commits during the last 14 day(s) which contain
a total of 128 files changed, 4990 insertions(+), 895 deletions(-).
The main changes are:
1) Add XDP multi-buffer support and implement it for the mvneta driver,
from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen.
2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc
infra, from Kumar Kartikeya Dwivedi.
3) Extend BPF cgroup programs to export custom ret value to userspace via
two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu.
4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima.
5) Complete missing UAPI BPF helper description and change bpf_doc.py script
to enforce consistent & complete helper documentation, from Usama Arif.
6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to
follow tc-based APIs, from Andrii Nakryiko.
7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu.
8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters
and setters, from Christy Lee.
9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to
reduce overhead, from Kui-Feng Lee.
10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new()
utility function, from Mauricio Vásquez.
11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau.
12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits)
selftests, bpf: Do not yet switch to new libbpf XDP APIs
selftests, xsk: Fix rx_full stats test
bpf: Fix flexible_array.cocci warnings
xdp: disable XDP_REDIRECT for xdp frags
bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
net: xdp: introduce bpf_xdp_pointer utility routine
bpf: generalise tail call map compatibility check
libbpf: Add SEC name for xdp frags programs
bpf: selftests: update xdp_adjust_tail selftest to include xdp frags
bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
bpf: introduce frags support to bpf_prog_test_run_xdp()
bpf: move user_size out of bpf_test_init
bpf: add frags support to xdp copy helpers
bpf: add frags support to the bpf_xdp_adjust_tail() API
bpf: introduce bpf_xdp_get_buff_len helper
net: mvneta: enable jumbo frames if the loaded XDP program support frags
bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program
net: mvneta: add frags support to XDP_TX
xdp: add frags support to xdp_return_{buff/frame}
...
====================
Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The commit 04c7820b77 ("bpf: tcp: Bpf iter batching and lock_sock")
introduces the batching algorithm to iterate TCP sockets with more
consistency.
This patch uses the same algorithm to iterate AF_UNIX sockets.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/r/20220113002849.4384-3-kuniyu@amazon.co.jp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, unix_next_socket() is overloaded depending on the 2nd argument.
If it is NULL, unix_next_socket() returns the first socket in the hash. If
not NULL, it returns the next socket in the same hash list or the first
socket in the next non-empty hash list.
This patch refactors unix_next_socket() into two functions unix_get_first()
and unix_get_next(). unix_get_first() newly acquires a lock and returns
the first socket in the list. unix_get_next() returns the next socket in a
list or releases a lock and falls back to unix_get_first().
In the following patch, bpf iter holds entire sockets in a list and always
releases the lock before .show(). It always calls unix_get_first() to
acquire a lock in each iteration. So, this patch makes the change easier
to follow.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Link: https://lore.kernel.org/r/20220113002849.4384-2-kuniyu@amazon.co.jp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2021-12-30
The following pull-request contains BPF updates for your *net-next* tree.
We've added 72 non-merge commits during the last 20 day(s) which contain
a total of 223 files changed, 3510 insertions(+), 1591 deletions(-).
The main changes are:
1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii.
2) Beautify and de-verbose verifier logs, from Christy.
3) Composable verifier types, from Hao.
4) bpf_strncmp helper, from Hou.
5) bpf.h header dependency cleanup, from Jakub.
6) get_func_[arg|ret|arg_cnt] helpers, from Jiri.
7) Sleepable local storage, from KP.
8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.
There's a lot of missing includes this was masking. Primarily
in networking tho, this time.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
This patch enables the "/proc/sys/net/unix/max_dgram_qlen" sysctl to be
exposed to non-init user namespaces. max_dgram_qlen is used as the default
"sk_max_ack_backlog" value for when a unix socket is created.
Currently, when a networking namespace is initialized, its unix sysctls
are exposed only if the user namespace that "owns" it is the init user
namespace. If there is an non-init user namespace that "owns" a networking
namespace (for example, in the case after we call clone() with both
CLONE_NEWUSER and CLONE_NEWNET set), the sysctls are hidden from view
and not configurable.
Exposing the unix sysctl is safe because any changes made to it will be
limited in scope to the networking namespace the non-init user namespace
"owns" and has privileges over (changes won't affect any other net
namespace). There is also no possibility of a non-privileged user namespace
messing up the net namespace sysctls it shares with its parent user namespace.
When a new user namespace is created without unsharing the network namespace
(eg calling clone() with CLONE_NEWUSER), the new user namespace shares its
parent's network namespace. Write access is protected by the mode set
in the sysctl's ctl_table (and enforced by procfs). Here in the case of
"max_dgram_qlen", 0644 is set; only the user owner has write access.
v1 -> v2:
* Add more detail to commit message, specify the
"/proc/sys/net/unix/max_dgram_qlen" sysctl in commit message.
Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we bind an AF_UNIX socket without a name specified, the kernel selects
an available one from 0x00000 to 0xFFFFF. unix_autobind() starts searching
from a number in the 'static' variable and increments it after acquiring
two locks.
If multiple processes try autobind, they obtain the same lock and check if
a socket in the hash list has the same name. If not, one process uses it,
and all except one end up retrying the _next_ number (actually not, it may
be incremented by the other processes). The more we autobind sockets in
parallel, the longer the latency gets. We can avoid such a race by
searching for a name from a random number.
These show latency in unix_autobind() while 64 CPUs are simultaneously
autobind-ing 1024 sockets for each.
Without this patch:
usec : count distribution
0 : 1176 |*** |
2 : 3655 |*********** |
4 : 4094 |************* |
6 : 3831 |************ |
8 : 3829 |************ |
10 : 3844 |************ |
12 : 3638 |*********** |
14 : 2992 |********* |
16 : 2485 |******* |
18 : 2230 |******* |
20 : 2095 |****** |
22 : 1853 |***** |
24 : 1827 |***** |
26 : 1677 |***** |
28 : 1473 |**** |
30 : 1573 |***** |
32 : 1417 |**** |
34 : 1385 |**** |
36 : 1345 |**** |
38 : 1344 |**** |
40 : 1200 |*** |
With this patch:
usec : count distribution
0 : 1855 |****** |
2 : 6464 |********************* |
4 : 9936 |******************************** |
6 : 12107 |****************************************|
8 : 10441 |********************************** |
10 : 7264 |*********************** |
12 : 4254 |************** |
14 : 2538 |******** |
16 : 1596 |***** |
18 : 1088 |*** |
20 : 800 |** |
22 : 670 |** |
24 : 601 |* |
26 : 562 |* |
28 : 525 |* |
30 : 446 |* |
32 : 378 |* |
34 : 337 |* |
36 : 317 |* |
38 : 314 |* |
40 : 298 | |
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
To replace unix_table_lock with per-hash locks in the next patch, we need
to save a hash in each socket because /proc/net/unix or BPF prog iterate
sockets while holding a hash table lock and release it later in a different
function.
Currently, we store a real/pseudo hash in struct unix_address. However, we
do not allocate it to unbound sockets, nor should we do just for that. For
this purpose, we can use sk_hash. Then, we no longer use the hash field in
struct unix_address and can remove it.
Also, this patch does
- rename unix_insert_socket() to unix_insert_unbound_socket()
- remove the redundant list argument from __unix_insert_socket() and
unix_insert_unbound_socket()
- use 'unsigned int' instead of 'unsigned' in __unix_set_addr_hash()
- remove 'inline' from unix_remove_socket() and
unix_insert_unbound_socket().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds three helper functions that calculate hashes for unbound
sockets and bound sockets with BSD/abstract addresses.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In BSD and abstract address cases, we store sockets in the hash table with
keys between 0 and UNIX_HASH_SIZE - 1. However, the hash saved in a socket
varies depending on its address type; sockets with BSD addresses always
have UNIX_HASH_SIZE in their unix_sk(sk)->addr->hash.
This is just for the UNIX_ABSTRACT() macro used to check the address type.
The difference of the saved hashes comes from the first byte of the address
in the first place. So, we can test it directly.
Then we can keep a real hash in each socket and replace unix_table_lock
with per-hash locks in the later patch.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
To terminate address with '\0' in unix_bind_bsd(), we add
unix_create_addr() and call it in unix_bind_bsd() and unix_bind_abstract().
Also, unix_bind_abstract() does not return -EEXIST. Only
kern_path_create() and vfs_mknod() in unix_bind_bsd() can return it,
so we move the last error check in unix_bind() to unix_bind_bsd().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch removes unix_mkname() and postpones calculating a hash to
unix_bind_abstract(). Some BSD stuffs still remain in unix_bind()
though, the next patch packs them into unix_bind_bsd().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We should not call unix_mkname() before unix_find_other() and instead do
the same thing where necessary based on the address type:
- terminating the address with '\0' in unix_find_bsd()
- calculating the hash in unix_find_abstract().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
unix_mkname() tests socket address length and family and does some
processing based on the address type. It is called in the early stage,
and therefore some instructions are redundant and can end up in vain.
The address length/family tests are done twice in unix_bind(). Also, the
address type is rechecked later in unix_bind() and unix_find_other(), where
we can do the same processing. Moreover, in the BSD address case, the hash
is set to 0 but never used and confusing.
This patch moves the address tests out of unix_mkname(), and the following
patches move the other part into appropriate places and remove
unix_mkname() finally.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We can return an error as a pointer and need not pass an additional
argument to unix_find_other().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As done in the commit fa42d910a3 ("unix_bind(): take BSD and abstract
address cases into new helpers"), this patch moves BSD and abstract address
cases from unix_find_other() into unix_find_bsd() and unix_find_abstract().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We do not use struct socket in unix_autobind() and pass struct sock to
unix_bind_bsd() and unix_bind_abstract(). Let's pass it to unix_autobind()
as well.
Also, this patch fixes these errors by checkpatch.pl.
ERROR: do not use assignment in if condition
#1795: FILE: net/unix/af_unix.c:1795:
+ if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
CHECK: Logical continuations should be on the previous line
#1796: FILE: net/unix/af_unix.c:1796:
+ if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
+ && (err = unix_autobind(sock)) != 0)
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The length of the AF_UNIX socket address contains an offset to the member
sun_path of struct sockaddr_un.
Currently, the preceding member is just sun_family, and its type is
sa_family_t and resolved to short. Therefore, the offset is represented by
sizeof(short). However, it is not clear and fragile to changes in struct
sockaddr_storage or sockaddr_un.
This commit makes it clear and robust by rewriting sizeof() with
offsetof().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On kernels before v5.15, calling read() on a unix socket after
shutdown(SHUT_RD) or shutdown(SHUT_RDWR) would return the data
previously written or EOF. But now, while read() after
shutdown(SHUT_RD) still behaves the same way, read() after
shutdown(SHUT_RDWR) always fails with -EINVAL.
This behaviour change was apparently inadvertently introduced as part of
a bug fix for a different regression caused by the commit adding sockmap
support to af_unix, commit 94531cfcbe ("af_unix: Add
unix_stream_proto for sockmap"). Those commits, for unclear reasons,
started setting the socket state to TCP_CLOSE on shutdown(SHUT_RDWR),
while this state change had previously only been done in
unix_release_sock().
Restore the original behaviour. The sockmap tests in
tests/selftests/bpf continue to pass after this patch.
Fixes: d0c6416bd7 ("unix: Fix an issue in unix_shutdown causing the other end read/write failures")
Link: https://lore.kernel.org/lkml/20211111140000.GA10779@axis.com/
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is distracting really, let's make this simpler,
because many callers had to take care of this
by themselves, even if on x86 this adds more
code than really needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Yucong noticed we can't poll() sockets in sockmap even
when they are the destination sockets of redirections.
This is because we never poll any psock queues in ->poll(),
except for TCP. With ->sock_is_readable() now we can
overwrite >sock_is_readable(), invoke and implement it for
both UDP and AF_UNIX sockets.
Reported-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211008203306.37525-4-xiyou.wangcong@gmail.com
Then name of this protocol changed in commit 94531cfcbe ("af_unix: Add
unix_stream_proto for sockmap") because that commit added stream support
to the af_unix protocol. Renaming the existing protocol makes a ChromeOS
protocol test[1] fail now that the name has changed in
/proc/net/protocols from "UNIX" to "UNIX-DGRAM".
Let's put the name back to how it was while keeping the stream protocol
as "UNIX-STREAM" so that the procfs interface doesn't change. This fixes
the test and maintains backwards compatibility in proc.
Cc: Jiang Wang <jiang.wang@bytedance.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Cong Wang <cong.wang@bytedance.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Dmitry Osipenko <digetx@gmail.com>
Link: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/tast-tests/src/chromiumos/tast/local/bundles/cros/network/supported_protocols.go;l=50;drc=e8b1c3f94cb40a054f4aa1ef1aff61e75dc38f18 [1]
Fixes: 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf 2021-10-07
We've added 7 non-merge commits during the last 8 day(s) which contain
a total of 8 files changed, 38 insertions(+), 21 deletions(-).
The main changes are:
1) Fix ARM BPF JIT to preserve caller-saved regs for DIV/MOD JIT-internal
helper call, from Johan Almbladh.
2) Fix integer overflow in BPF stack map element size calculation when
used with preallocation, from Tatsuhiko Yasumatsu.
3) Fix an AF_UNIX regression due to added BPF sockmap support related
to shutdown handling, from Jiang Wang.
4) Fix a segfault in libbpf when generating light skeletons from objects
without BTF, from Kumar Kartikeya Dwivedi.
5) Fix a libbpf memory leak in strset to free the actual struct strset
itself, from Andrii Nakryiko.
6) Dual-license bpf_insn.h similarly as we did for libbpf and bpftool,
with ACKs from all contributors, from Luca Boccassi.
====================
Link: https://lore.kernel.org/r/20211007135010.21143-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap") sets
unix domain socket peer state to TCP_CLOSE in unix_shutdown. This could
happen when the local end is shutdown but the other end is not. Then,
the other end will get read or write failures which is not expected.
Fix the issue by setting the local state to shutdown.
Fixes: 94531cfcbe ("af_unix: Add unix_stream_proto for sockmap")
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211004232530.2377085-1-jiang.wang@bytedance.com
Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations
are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred.
In order to fix this issue, this patch adds a new spinlock that needs
to be used whenever these fields are read or written.
Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently
reading sk->sk_peer_pid which makes no sense, as this field
is only possibly set by AF_UNIX sockets.
We will have to clean this in a separate patch.
This could be done by reverting b48596d1dc "Bluetooth: L2CAP: Add get_peer_pid callback"
or implementing what was truly expected.
Fixes: 109f6e39fa ("af_unix: Allow SO_PEERCRED to work across namespaces.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
unix_create1() returns NULL on error, and the callers assume that it never
fails for reasons other than out of memory. So, the callers always return
-ENOMEM when unix_create1() fails.
However, it also returns NULL when the number of af_unix sockets exceeds
twice the limit controlled by sysctl: fs.file-max. In this case, the
callers should return -ENFILE like alloc_empty_file().
This patch changes unix_create1() to return the correct error value instead
of NULL on error.
Out of curiosity, the assumption has been wrong since 1999 due to this
change introduced in 2.2.4 [0].
diff -u --recursive --new-file v2.2.3/linux/net/unix/af_unix.c linux/net/unix/af_unix.c
--- v2.2.3/linux/net/unix/af_unix.c Tue Jan 19 11:32:53 1999
+++ linux/net/unix/af_unix.c Sun Mar 21 07:22:00 1999
@@ -388,6 +413,9 @@
{
struct sock *sk;
+ if (atomic_read(&unix_nr_socks) >= 2*max_files)
+ return NULL;
+
MOD_INC_USE_COUNT;
sk = sk_alloc(PF_UNIX, GFP_KERNEL, 1);
if (!sk) {
[0]: https://cdn.kernel.org/pub/linux/kernel/v2.2/patch-2.2.4.gz
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot reported another data-race in af_unix [1]
Lets change __skb_insert() to use WRITE_ONCE() when changing
skb head qlen.
Also, change unix_dgram_poll() to use lockless version
of unix_recvq_full()
It is verry possible we can switch all/most unix_recvq_full()
to the lockless version, this will be done in a future kernel version.
[1] HEAD commit: 8596e589b7
BUG: KCSAN: data-race in skb_queue_tail / unix_dgram_poll
write to 0xffff88814eeb24e0 of 4 bytes by task 25815 on cpu 0:
__skb_insert include/linux/skbuff.h:1938 [inline]
__skb_queue_before include/linux/skbuff.h:2043 [inline]
__skb_queue_tail include/linux/skbuff.h:2076 [inline]
skb_queue_tail+0x80/0xa0 net/core/skbuff.c:3264
unix_dgram_sendmsg+0xff2/0x1600 net/unix/af_unix.c:1850
sock_sendmsg_nosec net/socket.c:703 [inline]
sock_sendmsg net/socket.c:723 [inline]
____sys_sendmsg+0x360/0x4d0 net/socket.c:2392
___sys_sendmsg net/socket.c:2446 [inline]
__sys_sendmmsg+0x315/0x4b0 net/socket.c:2532
__do_sys_sendmmsg net/socket.c:2561 [inline]
__se_sys_sendmmsg net/socket.c:2558 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff88814eeb24e0 of 4 bytes by task 25834 on cpu 1:
skb_queue_len include/linux/skbuff.h:1869 [inline]
unix_recvq_full net/unix/af_unix.c:194 [inline]
unix_dgram_poll+0x2bc/0x3e0 net/unix/af_unix.c:2777
sock_poll+0x23e/0x260 net/socket.c:1288
vfs_poll include/linux/poll.h:90 [inline]
ep_item_poll fs/eventpoll.c:846 [inline]
ep_send_events fs/eventpoll.c:1683 [inline]
ep_poll fs/eventpoll.c:1798 [inline]
do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226
__do_sys_epoll_wait fs/eventpoll.c:2238 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2233 [inline]
__x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x0000001b -> 0x00000001
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25834 Comm: syz-executor.1 Tainted: G W 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 86b18aaa2b ("skbuff: fix a data race in skb_queue_len()")
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
bpf-next 2021-08-31
We've added 116 non-merge commits during the last 17 day(s) which contain
a total of 126 files changed, 6813 insertions(+), 4027 deletions(-).
The main changes are:
1) Add opaque bpf_cookie to perf link which the program can read out again,
to be used in libbpf-based USDT library, from Andrii Nakryiko.
2) Add bpf_task_pt_regs() helper to access userspace pt_regs, from Daniel Xu.
3) Add support for UNIX stream type sockets for BPF sockmap, from Jiang Wang.
4) Allow BPF TCP congestion control progs to call bpf_setsockopt() e.g. to switch
to another congestion control algorithm during init, from Martin KaFai Lau.
5) Extend BPF iterator support for UNIX domain sockets, from Kuniyuki Iwashima.
6) Allow bpf_{set,get}sockopt() calls from setsockopt progs, from Prankur Gupta.
7) Add bpf_get_netns_cookie() helper for BPF_PROG_TYPE_{SOCK_OPS,CGROUP_SOCKOPT}
progs, from Xu Liu and Stanislav Fomichev.
8) Support for __weak typed ksyms in libbpf, from Hao Luo.
9) Shrink struct cgroup_bpf by 504 bytes through refactoring, from Dave Marchevsky.
10) Fix a smatch complaint in verifier's narrow load handling, from Andrey Ignatov.
11) Fix BPF interpreter's tail call count limit, from Daniel Borkmann.
12) Big batch of improvements to BPF selftests, from Magnus Karlsson, Li Zhijian,
Yucong Sun, Yonghong Song, Ilya Leoshkevich, Jussi Maki, Ilya Leoshkevich, others.
13) Another big batch to revamp XDP samples in order to give them consistent look
and feel, from Kumar Kartikeya Dwivedi.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (116 commits)
MAINTAINERS: Remove self from powerpc BPF JIT
selftests/bpf: Fix potential unreleased lock
samples: bpf: Fix uninitialized variable in xdp_redirect_cpu
selftests/bpf: Reduce more flakyness in sockmap_listen
bpf: Fix bpf-next builds without CONFIG_BPF_EVENTS
bpf: selftests: Add dctcp fallback test
bpf: selftests: Add connect_to_fd_opts to network_helpers
bpf: selftests: Add sk_state to bpf_tcp_helpers.h
bpf: tcp: Allow bpf-tcp-cc to call bpf_(get|set)sockopt
selftests: xsk: Preface options with opt
selftests: xsk: Make enums lower case
selftests: xsk: Generate packets from specification
selftests: xsk: Generate packet directly in umem
selftests: xsk: Simplify cleanup of ifobjects
selftests: xsk: Decrease sending speed
selftests: xsk: Validate tx stats on tx thread
selftests: xsk: Simplify packet validation in xsk tests
selftests: xsk: Rename worker_* functions that are not thread entry points
selftests: xsk: Disassociate umem size with packets sent
selftests: xsk: Remove end-of-test packet
...
====================
Link: https://lore.kernel.org/r/20210830225618.11634-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Previously, sockmap for AF_UNIX protocol only supports
dgram type. This patch add unix stream type support, which
is similar to unix_dgram_proto. To support sockmap, dgram
and stream cannot share the same unix_proto anymore, because
they have different implementations, such as unhash for stream
type (which will remove closed or disconnected sockets from the map),
so rename unix_proto to unix_dgram_proto and add a new
unix_stream_proto.
Also implement stream related sockmap functions.
And add dgram key words to those dgram specific functions.
Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-3-jiang.wang@bytedance.com
To support sockmap for af_unix stream type, implement
read_sock, which is similar to the read_sock for unix
dgram sockets.
Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-2-jiang.wang@bytedance.com
edumazet@google.com pointed out that queue_oob
does not check socket state after acquiring
the lock. He also pointed to an incorrect usage
of kfree_skb and an unnecessary setting of skb
length. This patch addresses those issue.
Signed-off-by: Rao Shoaib <Rao.Shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements the BPF iterator for the UNIX domain socket.
Currently, the batch optimisation introduced for the TCP iterator in the
commit 04c7820b77 ("bpf: tcp: Bpf iter batching and lock_sock") is not
used for the UNIX domain socket. It will require replacing the big lock
for the hash table with small locks for each hash list not to block other
processes.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210814015718.42704-2-kuniyu@amazon.co.jp
Daniel Borkmann says:
====================
bpf-next 2021-08-10
We've added 31 non-merge commits during the last 8 day(s) which contain
a total of 28 files changed, 3644 insertions(+), 519 deletions(-).
1) Native XDP support for bonding driver & related BPF selftests, from Jussi Maki.
2) Large batch of new BPF JIT tests for test_bpf.ko that came out as a result from
32-bit MIPS JIT development, from Johan Almbladh.
3) Rewrite of netcnt BPF selftest and merge into test_progs, from Stanislav Fomichev.
4) Fix XDP bpf_prog_test_run infra after net to net-next merge, from Andrii Nakryiko.
5) Follow-up fix in unix_bpf_update_proto() to enforce socket type, from Cong Wang.
6) Fix bpf-iter-tcp4 selftest to print the correct dest IP, from Jose Blanquicet.
7) Various misc BPF XDP sample improvements, from Niklas Söderlund, Matthew Cover,
and Muhammad Falak R Wani.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
bpf, tests: Add tail call test suite
bpf, tests: Add tests for BPF_CMPXCHG
bpf, tests: Add tests for atomic operations
bpf, tests: Add test for 32-bit context pointer argument passing
bpf, tests: Add branch conversion JIT test
bpf, tests: Add word-order tests for load/store of double words
bpf, tests: Add tests for ALU operations implemented with function calls
bpf, tests: Add more ALU64 BPF_MUL tests
bpf, tests: Add more BPF_LSH/RSH/ARSH tests for ALU64
bpf, tests: Add more ALU32 tests for BPF_LSH/RSH/ARSH
bpf, tests: Add more tests of ALU32 and ALU64 bitwise operations
bpf, tests: Fix typos in test case descriptions
bpf, tests: Add BPF_MOV tests for zero and sign extension
bpf, tests: Add BPF_JMP32 test cases
samples, bpf: Add an explict comment to handle nested vlan tagging.
selftests/bpf: Add tests for XDP bonding
selftests/bpf: Fix xdp_tx.c prog section name
net, core: Allow netdev_lower_get_next_private_rcu in bh context
bpf, devmap: Exclude XDP broadcast to master device
net, bonding: Add XDP support to the bonding driver
...
====================
Link: https://lore.kernel.org/r/20210810130038.16927-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds OOB support for AF_UNIX sockets.
The semantics is same as TCP.
The last byte of a message with the OOB flag is
treated as the OOB byte. The byte is separated into
a skb and a pointer to the skb is stored in unix_sock.
The pointer is used to enforce OOB semantics.
Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As of now, only AF_UNIX datagram socket supports sockmap. But
unix_proto is shared for all kinds of AF_UNIX sockets, so we
have to check the socket type in unix_bpf_update_proto() to
explicitly reject other types, otherwise they could be added
into sockmap, too.
Fixes: c63829182c ("af_unix: Implement ->psock_update_sk_prot()")
Reported-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210731195038.8084-1-xiyou.wangcong@gmail.com
Andrii Nakryiko says:
====================
bpf-next 2021-07-30
We've added 64 non-merge commits during the last 15 day(s) which contain
a total of 83 files changed, 5027 insertions(+), 1808 deletions(-).
The main changes are:
1) BTF-guided binary data dumping libbpf API, from Alan.
2) Internal factoring out of libbpf CO-RE relocation logic, from Alexei.
3) Ambient BPF run context and cgroup storage cleanup, from Andrii.
4) Few small API additions for libbpf 1.0 effort, from Evgeniy and Hengqi.
5) bpf_program__attach_kprobe_opts() fixes in libbpf, from Jiri.
6) bpf_{get,set}sockopt() support in BPF iterators, from Martin.
7) BPF map pinning improvements in libbpf, from Martynas.
8) Improved module BTF support in libbpf and bpftool, from Quentin.
9) Bpftool cleanups and documentation improvements, from Quentin.
10) Libbpf improvements for supporting CO-RE on old kernels, from Shuyi.
11) Increased maximum cgroup storage size, from Stanislav.
12) Small fixes and improvements to BPF tests and samples, from various folks.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (64 commits)
tools: bpftool: Complete metrics list in "bpftool prog profile" doc
tools: bpftool: Document and add bash completion for -L, -B options
selftests/bpf: Update bpftool's consistency script for checking options
tools: bpftool: Update and synchronise option list in doc and help msg
tools: bpftool: Complete and synchronise attach or map types
selftests/bpf: Check consistency between bpftool source, doc, completion
tools: bpftool: Slightly ease bash completion updates
unix_bpf: Fix a potential deadlock in unix_dgram_bpf_recvmsg()
libbpf: Add btf__load_vmlinux_btf/btf__load_module_btf
tools: bpftool: Support dumping split BTF by id
libbpf: Add split BTF support for btf__load_from_kernel_by_id()
tools: Replace btf__get_from_id() with btf__load_from_kernel_by_id()
tools: Free BTF objects at various locations
libbpf: Rename btf__get_from_id() as btf__load_from_kernel_by_id()
libbpf: Rename btf__load() as btf__load_into_kernel()
libbpf: Return non-null error on failures in libbpf_find_prog_btf_id()
bpf: Emit better log message if bpf_iter ctx arg btf_id == 0
tools/resolve_btfids: Emit warnings and patch zero id for missing symbols
bpf: Increase supported cgroup storage value size
libbpf: Fix race when pinning maps in parallel
...
====================
Link: https://lore.kernel.org/r/20210730225606.1897330-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As Eric noticed, __unix_dgram_recvmsg() may acquire u->iolock
too, so we have to release it before calling this function.
Fixes: 9825d866ce ("af_unix: Implement unix_dgram_bpf_recvmsg()")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
unix_gc() assumes that candidate sockets can never gain an external
reference (i.e. be installed into an fd) while the unix_gc_lock is
held. Except for MSG_PEEK this is guaranteed by modifying inflight
count under the unix_gc_lock.
MSG_PEEK does not touch any variable protected by unix_gc_lock (file
count is not), yet it needs to be serialized with garbage collection.
Do this by locking/unlocking unix_gc_lock:
1) increment file count
2) lock/unlock barrier to make sure incremented file count is visible
to garbage collection
3) install file into fd
This is a lock barrier (unlike smp_mb()) that ensures that garbage
collection is run completely before or completely after the barrier.
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
