net/unix/*.c include many unnecessary header files (rtnetlink.h,
netdevice.h, etc).
Let's clean them up.
af_unix.c:
+uapi/linux/sockios.h : Only exist under include/uapi
+uapi/linux/termios.h : Only exist under include/uapi
-linux/freezer.h : No longer use freezable_schedule_timeout()
-linux/in.h : No ipv4_is_XXX() etc
-linux/module.h : No longer support CONFIG_UNIX=m
-linux/netdevice.h : No dev used
-linux/rtnetlink.h : Not part of rtnetlink API
-linux/signal.h : signal_pending() is defined in sched/signal.h
-linux/stat.h : No struct stat used
-net/checksum.h : CHECKSUM_UNNECESSARY is defined in skbuff.h
diag.c:
+linux/dcache.h : struct dentry in sk_diag_dump_vfs()
+linux/user_namespace.h : struct user_namespace in sk_diag_dump_uid()
+uapi/linux/unix_diag.h : Only exist under include/uapi/
garbage.c:
+linux/list.h : struct unix_{vertex,edge}, etc
+linux/workqueue.h : DECLARE_WORK(unix_gc_work, ...)
-linux/file.h : No fget() etc
-linux/kernel.h : No cond_resched() etc
-linux/netdevice.h : No dev used
-linux/proc_fs.h : No procfs provided
-linux/string.h : No memcpy(), kmemdup(), etc
sysctl_net_unix.c:
+linux/string.h : kmemdup()
+net/net_namespace.h : struct net, net_eq()
-linux/mm.h : slab.h is enough
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250318034934.86708-5-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
include/net/af_unix.h indirectly includes some definitions for structs.
Let's include such headers explicitly.
linux/atomic.h : scm_stat.nr_fds
linux/net.h : unix_sock.peer_wq
linux/path.h : unix_sock.path
linux/spinlock.h : unix_sock.lock
linux/wait.h : unix_sock.peer_wake
uapi/linux/un.h : unix_address.name[]
linux/socket.h is removed as the structs there are not used directly,
and linux/un.h is clarified with uapi as un.h only exists under
include/uapi.
While at it, duplicate headers are removed from .c files.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250318034934.86708-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/af_unix.h is included by core and some LSMs, but most definitions
need not be.
Let's move struct unix_{vertex,edge} to net/unix/garbage.c and other
definitions to net/unix/af_unix.h.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20250318034934.86708-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is a prep patch to make the following changes cleaner.
No functional change intended.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20250318034934.86708-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After running the 'sendmsg02' program of Linux Test Project (LTP),
kmemleak reports the following memory leak:
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff888243866800 (size 2048):
comm "sendmsg02", pid 67, jiffies 4294903166
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 5e 00 00 00 00 00 00 00 ........^.......
01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace (crc 7e96a3f2):
kmemleak_alloc+0x56/0x90
kmem_cache_alloc_noprof+0x209/0x450
sk_prot_alloc.constprop.0+0x60/0x160
sk_alloc+0x32/0xc0
unix_create1+0x67/0x2b0
unix_create+0x47/0xa0
__sock_create+0x12e/0x200
__sys_socket+0x6d/0x100
__x64_sys_socket+0x1b/0x30
x64_sys_call+0x7e1/0x2140
do_syscall_64+0x54/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Commit 689c398885cc ("af_unix: Defer sock_put() to clean up path in
unix_dgram_sendmsg().") defers sock_put() in the error handling path.
However, it fails to account for the condition 'msg->msg_namelen != 0',
resulting in a memory leak when the code jumps to the 'lookup' label.
Fix issue by calling sock_put() if 'msg->msg_namelen != 0' is met.
Fixes: 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().")
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Acked-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250225021457.1824-1-ahuang12@lenovo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix an issue with the sparse static analysis tool where an
"undefined 'other'" error occurs due to `__releases(&unix_sk(other)->lock)`
being placed before 'other' is in scope.
Remove the `__releases()` annotation from the `unix_wait_for_peer()`
function to eliminate the sparse error. The annotation references `other`
before it is declared, leading to a false positive error during static
analysis.
Since AF_UNIX does not use sparse annotations, this annotation is
unnecessary and does not impact functionality.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250218141045.38947-1-purvayeshi550@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is based on Donald Hunter's patch.
These functions could fail for various reasons, sometimes
triggering kfree_skb().
* unix_stream_connect() : connect()
* unix_stream_sendmsg() : sendmsg()
* queue_oob() : sendmsg(MSG_OOB)
* unix_dgram_sendmsg() : sendmsg()
Such kfree_skb() is tied to the errno of connect() and
sendmsg(), and we need not define skb drop reasons.
Let's use consume_skb() not to churn kfree_skb() events.
Link: https://lore.kernel.org/netdev/eb30b164-7f86-46bf-a5d3-0f8bda5e9398@redhat.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-10-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is a follow-up of commit d460b04bc452 ("af_unix: Clean up
error paths in unix_stream_sendmsg().").
If we initialise skb with NULL in unix_stream_sendmsg(), we can
reuse the existing out_pipe label for the SEND_SHUTDOWN check.
Let's rename it and adjust the existing label as out_pipe_lock.
While at it, size and data_len are moved to the while loop scope.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-9-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
unix_dgram_disconnected() is called from two places:
1. when a connect()ed socket dis-connect()s or re-connect()s to
another socket
2. when sendmsg() fails because the peer socket that the client
has connect()ed to has been close()d
Then, the client's recv queue is purged to remove all messages from
the old peer socket.
Let's define a new drop reason for that case.
# echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable
# python3
>>> from socket import *
>>>
>>> # s1 has a message from s2
>>> s1, s2 = socketpair(AF_UNIX, SOCK_DGRAM)
>>> s2.send(b'hello world')
>>>
>>> # re-connect() drops the message from s2
>>> s3 = socket(AF_UNIX, SOCK_DGRAM)
>>> s3.bind('')
>>> s1.connect(s3.getsockname())
# cat /sys/kernel/tracing/trace_pipe
python3-250 ... kfree_skb: ... location=skb_queue_purge_reason+0xdc/0x110 reason: UNIX_DISCONNECT
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
unix_stream_read_skb() is called when BPF SOCKMAP reads some data
from a socket in the map.
SOCKMAP does not support MSG_OOB, and reading OOB results in a drop.
Let's set drop reasons respectively.
* SOCKET_CLOSE : the socket in SOCKMAP was close()d
* UNIX_SKIP_OOB : OOB was read from the socket in SOCKMAP
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
AF_UNIX SOCK_STREAM socket supports MSG_OOB.
When OOB data is sent to a socket, recv() will break at that point.
If the next recv() does not have MSG_OOB, the normal data following
the OOB data is returned.
Then, the OOB skb is dropped.
Let's define a new drop reason for that case in manage_oob().
# echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable
# python3
>>> from socket import *
>>> s1, s2 = socketpair(AF_UNIX)
>>> s1.send(b'a', MSG_OOB)
>>> s1.send(b'b')
>>> s2.recv(2)
b'b'
# cat /sys/kernel/tracing/trace_pipe
...
python3-223 ... kfree_skb: ... location=unix_stream_read_generic+0x59e/0xc20 reason: UNIX_SKIP_OOB
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
unix_sock_destructor() is called as sk->sk_destruct() just before
the socket is actually freed.
Let's use SKB_DROP_REASON_SOCKET_CLOSE for skb_queue_purge().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
unix_release_sock() is called when the last refcnt of struct file
is released.
Let's define a new drop reason SKB_DROP_REASON_SOCKET_CLOSE and
set it for kfree_skb() in unix_release_sock().
# echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable
# python3
>>> from socket import *
>>> s1, s2 = socketpair(AF_UNIX)
>>> s1.send(b'hello world')
>>> s2.close()
# cat /sys/kernel/tracing/trace_pipe
...
python3-280 ... kfree_skb: ... protocol=0 location=unix_release_sock+0x260/0x420 reason: SOCKET_CLOSE
To be precise, unix_release_sock() is also called for a new child
socket in unix_stream_connect() when something fails, but the new
sk does not have skb in the recv queue then and no event is logged.
Note that only tcp_inbound_ao_hash() uses a similar drop reason,
SKB_DROP_REASON_TCP_CLOSE, and this can be generalised later.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250116053441.5758-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
unix_our_peer() is used only in unix_may_send().
Let's inline it in unix_may_send().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The error path is complicated in unix_dgram_sendmsg() because there
are two timings when other could be non-NULL: when it's fetched from
unix_peer_get() and when it's looked up by unix_find_other().
Let's move unix_peer_get() to the else branch for unix_find_other()
and clean up the error paths.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When other has SOCK_DEAD in unix_dgram_sendmsg(), we hold
unix_state_lock() for the sender socket first.
However, we do not need it for sk->sk_type.
Let's move the lock down a bit.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When other has SOCK_DEAD in unix_dgram_sendmsg(), we call sock_put() for
it first and then set NULL to other before jumping to the error path.
This is to skip sock_put() in the error path.
Let's not set NULL to other and defer the sock_put() to the error path
to clean up the labels later.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
There are two paths jumping to the restart label in unix_dgram_sendmsg().
One requires another lookup and sk_filter(), but the other doesn't.
Let's split the label to make each flow more straightforward.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In unix_dgram_sendmsg(), we use a local variable sunaddr pointing
NULL or msg->msg_name based on msg->msg_namelen.
Let's remove sunaddr and simplify the usage.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When other is NULL in unix_dgram_sendmsg(), we check if sunaddr
is NULL before looking up a receiver socket.
There are three paths going through the check, but it's always
false for 2 out of the 3 paths: the first socket lookup and the
second 'goto restart'.
The condition can be true for the first 'goto restart' only when
SOCK_DEAD is flagged for the socket found with msg->msg_name.
Let's move the check to the single appropriate path.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We will introduce skb drop reason for AF_UNIX, then we need to
set an errno and a drop reason for each path.
Let's set an error only when it's needed in unix_dgram_sendmsg().
Then, we need not (re)set 0 to err.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
If we move send_sig() to the SEND_SHUTDOWN check before
the while loop, then we can reuse the same kfree_skb()
after the pipe_err_free label.
Let's gather the scattered kfree_skb()s in error paths.
While at it, some style issues are fixed, and the pipe_err_free
label is renamed to out_pipe to match other label names.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We will introduce skb drop reason for AF_UNIX, then we need to
set an errno and a drop reason for each path.
Let's set an error only when it's needed in unix_stream_sendmsg().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The label order is weird in unix_stream_connect(), and all NULL checks
are unnecessary if reordered.
Let's clean up the error paths to make it easy to set a drop reason
for each path.
While at it, a comment with the old style is updated.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We will introduce skb drop reason for AF_UNIX, then we need to
set an errno and a drop reason for each path.
Let's set an error only when it's needed in unix_stream_connect().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When `skb_splice_from_iter` was introduced, it inadvertently added
checksumming for AF_UNIX sockets. This resulted in significant
slowdowns, for example when using sendfile over unix sockets.
Using the test code in [1] in my test setup (2G single core qemu),
the client receives a 1000M file in:
- without the patch: 1482ms (+/- 36ms)
- with the patch: 652.5ms (+/- 22.9ms)
This commit addresses the issue by marking checksumming as unnecessary in
`unix_stream_sendmsg`
Cc: stable@vger.kernel.org
Signed-off-by: Frederik Deweerdt <deweerdt.lkml@gmail.com>
Fixes: 2e910b95329c ("net: Add a function to splice pages into an skbuff for MSG_SPLICE_PAGES")
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/Z1fMaHkRf8cfubuE@xiberoa
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When OOB skb has been already consumed, manage_oob() returns the next
skb if exists. In such a case, we need to fall back to the else branch
below.
Then, we want to keep holding spin_lock(&sk->sk_receive_queue.lock).
Let's move it out of if-else branch and add lightweight check before
spin_lock() for major use cases without OOB skb.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240905193240.17565-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When OOB skb has been already consumed, manage_oob() returns the next
skb if exists. In such a case, we need to fall back to the else branch
below.
Then, we need to keep two skbs and free them later with consume_skb()
and kfree_skb().
Let's rename unlinked_skb accordingly.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240905193240.17565-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since introduced, OOB skb holds an additional reference count with no
special reason and caused many issues.
Also, kfree_skb() and consume_skb() are used to decrement the count,
which is confusing.
Let's drop the unnecessary skb_get() in queue_oob() and corresponding
kfree_skb(), consume_skb(), and skb_unref().
Now unix_sk(sk)->oob_skb is just a pointer to skb in the receive queue,
so special handing is no longer needed in GC.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240816233921.57800-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
AF_UNIX socket tracks the most recent OOB packet (in its receive queue)
with an `oob_skb` pointer. BPF redirecting does not account for that: when
an OOB packet is moved between sockets, `oob_skb` is left outdated. This
results in a single skb that may be accessed from two different sockets.
Take the easy way out: silently drop MSG_OOB data targeting any socket that
is in a sockmap or a sockhash. Note that such silent drop is akin to the
fate of redirected skb's scm_fp_list (SCM_RIGHTS, SCM_CREDENTIALS).
For symmetry, forbid MSG_OOB in unix_bpf_recvmsg().
Fixes: 314001f0bf92 ("af_unix: Add OOB support")
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20240713200218.2140950-2-mhal@rbox.co
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
e3f02f32a050 ("ionic: fix kernel panic due to multi-buffer handling")
d9c04209990b ("ionic: Mark error paths in the data path as unlikely")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Even if OOB data is recv()ed, ioctl(SIOCATMARK) must return 1 when the
OOB skb is at the head of the receive queue and no new OOB data is queued.
Without fix:
# RUN msg_oob.no_peek.oob ...
# msg_oob.c:305:oob:Expected answ[0] (0) == oob_head (1)
# oob: Test terminated by assertion
# FAIL msg_oob.no_peek.oob
not ok 2 msg_oob.no_peek.oob
With fix:
# RUN msg_oob.no_peek.oob ...
# OK msg_oob.no_peek.oob
ok 2 msg_oob.no_peek.oob
Fixes: 314001f0bf92 ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, recv() is stopped at a consumed OOB skb even if a new
OOB skb is queued and we can ignore the old OOB skb.
>>> from socket import *
>>> c1, c2 = socket(AF_UNIX, SOCK_STREAM)
>>> c1.send(b'hellowor', MSG_OOB)
8
>>> c2.recv(1, MSG_OOB) # consume OOB data stays at middle of recvq.
b'r'
>>> c1.send(b'ld', MSG_OOB)
2
>>> c2.recv(10) # recv() stops at the old consumed OOB
b'hellowo' # should be 'hellowol'
manage_oob() should not stop recv() at the old consumed OOB skb if
there is a new OOB data queued.
Note that TCP behaviour is apparently wrong in this test case because
we can recv() the same OOB data twice.
Without fix:
# RUN msg_oob.no_peek.ex_oob_ahead_break ...
# msg_oob.c:138:ex_oob_ahead_break:AF_UNIX :hellowo
# msg_oob.c:139:ex_oob_ahead_break:Expected:hellowol
# msg_oob.c:141:ex_oob_ahead_break:Expected ret[0] (7) == expected_len (8)
# ex_oob_ahead_break: Test terminated by assertion
# FAIL msg_oob.no_peek.ex_oob_ahead_break
not ok 11 msg_oob.no_peek.ex_oob_ahead_break
With fix:
# RUN msg_oob.no_peek.ex_oob_ahead_break ...
# msg_oob.c:146:ex_oob_ahead_break:AF_UNIX :hellowol
# msg_oob.c:147:ex_oob_ahead_break:TCP :helloworl
# OK msg_oob.no_peek.ex_oob_ahead_break
ok 11 msg_oob.no_peek.ex_oob_ahead_break
Fixes: 314001f0bf92 ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Let's say a socket send()s "hello" with MSG_OOB and "world" without flags,
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX)
>>> c1.send(b'hello', MSG_OOB)
5
>>> c1.send(b'world')
5
and its peer recv()s "hell" and "o".
>>> c2.recv(10)
b'hell'
>>> c2.recv(1, MSG_OOB)
b'o'
Now the consumed OOB skb stays at the head of recvq to return a correct
value for ioctl(SIOCATMARK), which is broken now and fixed by a later
patch.
Then, if peer issues recv() with MSG_DONTWAIT, manage_oob() returns NULL,
so recv() ends up with -EAGAIN.
>>> c2.setblocking(False) # This causes -EAGAIN even with available data
>>> c2.recv(5)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
BlockingIOError: [Errno 11] Resource temporarily unavailable
However, next recv() will return the following available data, "world".
>>> c2.recv(5)
b'world'
When the consumed OOB skb is at the head of the queue, we need to fetch
the next skb to fix the weird behaviour.
Note that the issue does not happen without MSG_DONTWAIT because we can
retry after manage_oob().
This patch also adds a test case that covers the issue.
Without fix:
# RUN msg_oob.no_peek.ex_oob_break ...
# msg_oob.c:134:ex_oob_break:AF_UNIX :Resource temporarily unavailable
# msg_oob.c:135:ex_oob_break:Expected:ld
# msg_oob.c:137:ex_oob_break:Expected ret[0] (-1) == expected_len (2)
# ex_oob_break: Test terminated by assertion
# FAIL msg_oob.no_peek.ex_oob_break
not ok 8 msg_oob.no_peek.ex_oob_break
With fix:
# RUN msg_oob.no_peek.ex_oob_break ...
# OK msg_oob.no_peek.ex_oob_break
ok 8 msg_oob.no_peek.ex_oob_break
Fixes: 314001f0bf92 ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
After consuming OOB data, recv() reading the preceding data must break at
the OOB skb regardless of MSG_PEEK.
Currently, MSG_PEEK does not stop recv() for AF_UNIX, and the behaviour is
not compliant with TCP.
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX)
>>> c1.send(b'hello', MSG_OOB)
5
>>> c1.send(b'world')
5
>>> c2.recv(1, MSG_OOB)
b'o'
>>> c2.recv(9, MSG_PEEK) # This should return b'hell'
b'hellworld' # even with enough buffer.
Let's fix it by returning NULL for consumed skb and unlinking it only if
MSG_PEEK is not specified.
This patch also adds test cases that add recv(MSG_PEEK) before each recv().
Without fix:
# RUN msg_oob.peek.oob_ahead_break ...
# msg_oob.c:134:oob_ahead_break:AF_UNIX :hellworld
# msg_oob.c:135:oob_ahead_break:Expected:hell
# msg_oob.c:137:oob_ahead_break:Expected ret[0] (9) == expected_len (4)
# oob_ahead_break: Test terminated by assertion
# FAIL msg_oob.peek.oob_ahead_break
not ok 13 msg_oob.peek.oob_ahead_break
With fix:
# RUN msg_oob.peek.oob_ahead_break ...
# OK msg_oob.peek.oob_ahead_break
ok 13 msg_oob.peek.oob_ahead_break
Fixes: 314001f0bf92 ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When (AF_UNIX, SOCK_STREAM) socket connect()s to a listening socket,
the listener's sk_peer_pid/sk_peer_cred are copied to the client in
copy_peercred().
Then, two sk_peer_locks are held there; one is client's and another
is listener's.
However, the latter is not needed because we hold the listner's
unix_state_lock() there and unix_listen() cannot update the cred
concurrently.
Let's drop the unnecessary spin_lock() and use the bare spin_lock()
for the client to protect concurrent read by getsockopt(SO_PEERCRED).
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When (AF_UNIX, SOCK_STREAM) socket connect()s to a listening socket,
the listener's sk_peer_pid/sk_peer_cred are copied to the client in
copy_peercred().
Then, the client's sk_peer_pid and sk_peer_cred are always NULL, so
we need not call put_pid() and put_cred() there.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
init_peercred() is called in 3 places:
1. socketpair() : both sockets
2. connect() : child socket
3. listen() : listening socket
The first two need not hold sk_peer_lock because no one can
touch the socket.
Let's set cred/pid without holding lock for the two cases and
rename the old init_peercred() to update_peercred() to properly
reflect the use case.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
While GC is cleaning up cyclic references by SCM_RIGHTS,
unix_collect_skb() collects skb in the socket's recvq.
If the socket is TCP_LISTEN, we need to collect skb in the
embryo's queue. Then, both the listener's recvq lock and
the embroy's one are held.
The locking is always done in the listener -> embryo order.
Let's define it as unix_recvq_lock_cmp_fn() instead of using
spin_lock_nested().
Note that the reverse order is defined for consistency.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
While a SOCK_(STREAM|SEQPACKET) socket connect()s to another, we hold
two locks of them by unix_state_lock() and unix_state_lock_nested() in
unix_stream_connect().
Before unix_state_lock_nested(), the following is guaranteed by checking
sk->sk_state:
1. The first socket is TCP_LISTEN
2. The second socket is not the first one
3. Simultaneous connect() must fail
So, the client state can be TCP_CLOSE or TCP_LISTEN or TCP_ESTABLISHED.
Let's define the expected states as unix_state_lock_cmp_fn() instead of
using unix_state_lock_nested().
Note that 2. is detected by debug_spin_lock_before() and 3. cannot be
expressed as lock_cmp_fn.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When a SOCK_(STREAM|SEQPACKET) socket connect()s to another one, we need
to lock the two sockets to check their states in unix_stream_connect().
We use unix_state_lock() for the server and unix_state_lock_nested() for
client with tricky sk->sk_state check to avoid deadlock.
The possible deadlock scenario are the following:
1) Self connect()
2) Simultaneous connect()
The former is simple, attempt to grab the same lock, and the latter is
AB-BA deadlock.
After the server's unix_state_lock(), we check the server socket's state,
and if it's not TCP_LISTEN, connect() fails with -EINVAL.
Then, we avoid the former deadlock by checking the client's state before
unix_state_lock_nested(). If its state is not TCP_LISTEN, we can make
sure that the client and the server are not identical based on the state.
Also, the latter deadlock can be avoided in the same way. Due to the
server sk->sk_state requirement, AB-BA deadlock could happen only with
TCP_LISTEN sockets. So, if the client's state is TCP_LISTEN, we can
give up the second lock to avoid the deadlock.
CPU 1 CPU 2 CPU 3
connect(A -> B) connect(B -> A) listen(A)
--- --- ---
unix_state_lock(B)
B->sk_state == TCP_LISTEN
READ_ONCE(A->sk_state) == TCP_CLOSE
^^^^^^^^^
ok, will lock A unix_state_lock(A)
.--------------' WRITE_ONCE(A->sk_state, TCP_LISTEN)
| unix_state_unlock(A)
|
| unix_state_lock(A)
| A->sk_sk_state == TCP_LISTEN
| READ_ONCE(B->sk_state) == TCP_LISTEN
v ^^^^^^^^^^
unix_state_lock_nested(A) Don't lock B !!
Currently, while checking the client's state, we also check if it's
TCP_ESTABLISHED, but this is unlikely and can be checked after we know
the state is not TCP_CLOSE.
Moreover, if it happens after the second lock, we now jump to the restart
label, but it's unlikely that the server is not found during the retry,
so the jump is mostly to revist the client state check.
Let's remove the retry logic and check the state against TCP_CLOSE first.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
unix_dgram_connect() and unix_dgram_{send,recv}msg() lock the socket
and peer in ascending order of the socket address.
Let's define the order as unix_state_lock_cmp_fn() instead of using
unix_state_lock_nested().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When created, AF_UNIX socket is put into net->unx.table.buckets[],
and the hash is stored in sk->sk_hash.
* unbound socket : 0 <= sk_hash <= UNIX_HASH_MOD
When bind() is called, the socket could be moved to another bucket.
* pathname socket : 0 <= sk_hash <= UNIX_HASH_MOD
* abstract socket : UNIX_HASH_MOD + 1 <= sk_hash <= UNIX_HASH_MOD * 2 + 1
Then, we call unix_table_double_lock() which locks a single bucket
or two.
Let's define the order as unix_table_lock_cmp_fn() instead of using
spin_lock_nested().
The locking is always done in ascending order of sk->sk_hash, which
is the index of buckets/locks array allocated by kvmalloc_array().
sk_hash_A < sk_hash_B
<=> &locks[sk_hash_A].dep_map < &locks[sk_hash_B].dep_map
So, the relation of two sk->sk_hash can be derived from the addresses
of dep_map in the array of locks.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/pensando/ionic/ionic_txrx.c
d9c04209990b ("ionic: Mark error paths in the data path as unlikely")
491aee894a08 ("ionic: fix kernel panic in XDP_TX action")
net/ipv6/ip6_fib.c
b4cb4a1391dc ("net: use unrcu_pointer() helper")
b01e1c030770 ("ipv6: fix possible race in __fib6_drop_pcpu_from()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If the socket type is SOCK_STREAM or SOCK_SEQPACKET, unix_release_sock()
checks the length of the peer socket's recvq under unix_state_lock().
However, unix_stream_read_generic() calls skb_unlink() after releasing
the lock. Also, for SOCK_SEQPACKET, __skb_try_recv_datagram() unlinks
skb without unix_state_lock().
Thues, unix_state_lock() does not protect qlen.
Let's use skb_queue_empty_lockless() in unix_release_sock().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
