[ Upstream commit 83690b82d2 ]
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: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc04410af7 ]
unix_poll() and unix_dgram_poll() read sk->sk_err
without any lock held.
Add relevant READ_ONCE()/WRITE_ONCE() annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 83690b82d2 ("af_unix: Use skb_queue_empty_lockless() in unix_release_sock().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 45d872f0e6 ]
Once sk->sk_state is changed to TCP_LISTEN, it never changes.
unix_accept() takes advantage of this characteristics; it does not
hold the listener's unix_state_lock() and only acquires recvq lock
to pop one skb.
It means unix_state_lock() does not prevent the queue length from
changing in unix_stream_connect().
Thus, we need to use unix_recvq_full_lockless() to avoid data-race.
Now we remove unix_recvq_full() as no one uses it.
Note that we can remove READ_ONCE() for sk->sk_max_ack_backlog in
unix_recvq_full_lockless() because of the following reasons:
(1) For SOCK_DGRAM, it is a written-once field in unix_create1()
(2) For SOCK_STREAM and SOCK_SEQPACKET, it is changed under the
listener's unix_state_lock() in unix_listen(), and we hold
the lock in unix_stream_connect()
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bd9f2d0573 ]
net->unx.sysctl_max_dgram_qlen is exposed as a sysctl knob and can be
changed concurrently.
Let's use READ_ONCE() in unix_create1().
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit af4c733b6b ]
unix_stream_read_skb() is called from sk->sk_data_ready() context
where unix_state_lock() is not held.
Let's use READ_ONCE() there.
Fixes: 77462de14a ("af_unix: Add read_sock for stream socket types")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8a34d4e8d9 ]
The following functions read sk->sk_state locklessly and proceed only if
the state is TCP_ESTABLISHED.
* unix_stream_sendmsg
* unix_stream_read_generic
* unix_seqpacket_sendmsg
* unix_seqpacket_recvmsg
Let's use READ_ONCE() there.
Fixes: a05d2ad1c1 ("af_unix: Only allow recv on connected seqpacket sockets.")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a9bf9c7dc6 ]
As small optimisation, unix_stream_connect() prefetches the client's
sk->sk_state without unix_state_lock() and checks if it's TCP_CLOSE.
Later, sk->sk_state is checked again under unix_state_lock().
Let's use READ_ONCE() for the first check and TCP_CLOSE directly for
the second check.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b3cb764aa1 ]
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>
Stable-dep-of: a9bf9c7dc6 ("af_unix: Annotate data-race of sk->sk_state in unix_stream_connect().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eb0718fb3e ]
unix_poll() and unix_dgram_poll() read sk->sk_state locklessly and
calls unix_writable() which also reads sk->sk_state without holding
unix_state_lock().
Let's use READ_ONCE() in unix_poll() and unix_dgram_poll() and pass
it to unix_writable().
While at it, we remove TCP_SYN_SENT check in unix_dgram_poll() as
that state does not exist for AF_UNIX socket since the code was added.
Fixes: 1586a5877d ("af_unix: do not report POLLOUT on listeners")
Fixes: 3c73419c09 ("af_unix: fix 'poll for write'/ connected DGRAM sockets")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3a0f38eb28 ]
ioctl(SIOCINQ) calls unix_inq_len() that checks sk->sk_state first
and returns -EINVAL if it's TCP_LISTEN.
Then, for SOCK_STREAM sockets, unix_inq_len() returns the number of
bytes in recvq.
However, unix_inq_len() does not hold unix_state_lock(), and the
concurrent listen() might change the state after checking sk->sk_state.
If the race occurs, 0 is returned for the listener, instead of -EINVAL,
because the length of skb with embryo is 0.
We could hold unix_state_lock() in unix_inq_len(), but it's overkill
given the result is true for pre-listen() TCP_CLOSE state.
So, let's use READ_ONCE() for sk->sk_state in unix_inq_len().
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 942238f973 ]
sk->sk_state is changed under unix_state_lock(), but it's read locklessly
in many places.
This patch adds WRITE_ONCE() on the writer side.
We will add READ_ONCE() to the lockless readers in the following patches.
Fixes: 83301b5367 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 26bfb8b570 ]
When a SOCK_DGRAM socket connect()s to another socket, the both sockets'
sk->sk_state are changed to TCP_ESTABLISHED so that we can register them
to BPF SOCKMAP.
When the socket disconnects from the peer by connect(AF_UNSPEC), the state
is set back to TCP_CLOSE.
Then, the peer's state is also set to TCP_CLOSE, but the update is done
locklessly and unconditionally.
Let's say socket A connect()ed to B, B connect()ed to C, and A disconnects
from B.
After the first two connect()s, all three sockets' sk->sk_state are
TCP_ESTABLISHED:
$ ss -xa
Netid State Recv-Q Send-Q Local Address:Port Peer Address:PortProcess
u_dgr ESTAB 0 0 @A 641 * 642
u_dgr ESTAB 0 0 @B 642 * 643
u_dgr ESTAB 0 0 @C 643 * 0
And after the disconnect, B's state is TCP_CLOSE even though it's still
connected to C and C's state is TCP_ESTABLISHED.
$ ss -xa
Netid State Recv-Q Send-Q Local Address:Port Peer Address:PortProcess
u_dgr UNCONN 0 0 @A 641 * 0
u_dgr UNCONN 0 0 @B 642 * 643
u_dgr ESTAB 0 0 @C 643 * 0
In this case, we cannot register B to SOCKMAP.
So, when a socket disconnects from the peer, we should not set TCP_CLOSE to
the peer if the peer is connected to yet another socket, and this must be
done under unix_state_lock().
Note that we use WRITE_ONCE() for sk->sk_state as there are many lockless
readers. These data-races will be fixed in the following patches.
Fixes: 83301b5367 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 540bf24fba ]
A data-race condition has been identified in af_unix. In one data path,
the write function unix_release_sock() atomically writes to
sk->sk_shutdown using WRITE_ONCE. However, on the reader side,
unix_stream_sendmsg() does not read it atomically. Consequently, this
issue is causing the following KCSAN splat to occur:
BUG: KCSAN: data-race in unix_release_sock / unix_stream_sendmsg
write (marked) to 0xffff88867256ddbb of 1 bytes by task 7270 on cpu 28:
unix_release_sock (net/unix/af_unix.c:640)
unix_release (net/unix/af_unix.c:1050)
sock_close (net/socket.c:659 net/socket.c:1421)
__fput (fs/file_table.c:422)
__fput_sync (fs/file_table.c:508)
__se_sys_close (fs/open.c:1559 fs/open.c:1541)
__x64_sys_close (fs/open.c:1541)
x64_sys_call (arch/x86/entry/syscall_64.c:33)
do_syscall_64 (arch/x86/entry/common.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
read to 0xffff88867256ddbb of 1 bytes by task 989 on cpu 14:
unix_stream_sendmsg (net/unix/af_unix.c:2273)
__sock_sendmsg (net/socket.c:730 net/socket.c:745)
____sys_sendmsg (net/socket.c:2584)
__sys_sendmmsg (net/socket.c:2638 net/socket.c:2724)
__x64_sys_sendmmsg (net/socket.c:2753 net/socket.c:2750 net/socket.c:2750)
x64_sys_call (arch/x86/entry/syscall_64.c:33)
do_syscall_64 (arch/x86/entry/common.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
value changed: 0x01 -> 0x03
The line numbers are related to commit dd5a440a31 ("Linux 6.9-rc7").
Commit e1d09c2c2f ("af_unix: Fix data races around sk->sk_shutdown.")
addressed a comparable issue in the past regarding sk->sk_shutdown.
However, it overlooked resolving this particular data path.
This patch only offending unix_stream_sendmsg() function, since the
other reads seem to be protected by unix_state_lock() as discussed in
Link: https://lore.kernel.org/all/20240508173324.53565-1-kuniyu@amazon.com/
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240509081459.2807828-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 22dd70eb2c ]
Currently, we can read OOB data without MSG_OOB by using MSG_PEEK
when OOB data is sitting on the front row, which is apparently
wrong.
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
>>> c1.send(b'a', MSG_OOB)
1
>>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT)
b'a'
If manage_oob() is called when no data has been copied, we only
check if the socket enables SO_OOBINLINE or MSG_PEEK is not used.
Otherwise, the skb is returned as is.
However, here we should return NULL if MSG_PEEK is set and no data
has been copied.
Also, in such a case, we should not jump to the redo label because
we will be caught in the loop and hog the CPU until normal data
comes in.
Then, we need to handle skb == NULL case with the if-clause below
the manage_oob() block.
With this patch:
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
>>> c1.send(b'a', MSG_OOB)
1
>>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
BlockingIOError: [Errno 11] Resource temporarily unavailable
Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240410171016.7621-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 283454c8a1 ]
When we call recv() for AF_UNIX socket, we first peek one skb and
calls manage_oob() to check if the skb is sent with MSG_OOB.
However, when we fetch the next (and the following) skb, manage_oob()
is not called now, leading a wrong behaviour.
Let's say a socket send()s "hello" with MSG_OOB and the peer tries
to recv() 5 bytes with MSG_PEEK. Here, we should get only "hell"
without 'o', but actually not:
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
>>> c1.send(b'hello', MSG_OOB)
5
>>> c2.recv(5, MSG_PEEK)
b'hello'
The first skb fills 4 bytes, and the next skb is peeked but not
properly checked by manage_oob().
Let's move up the again label to call manage_oob() for evry skb.
With this patch:
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
>>> c1.send(b'hello', MSG_OOB)
5
>>> c2.recv(5, MSG_PEEK)
b'hell'
Fixes: 314001f0bf ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240410171016.7621-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 97af84a6bb ]
When touching unix_sk(sk)->inflight, we are always under
spin_lock(&unix_gc_lock).
Let's convert unix_sk(sk)->inflight to the normal unsigned long.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240123170856.41348-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 47d8ac011f ("af_unix: Fix garbage collector racing against connect()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b46f4eaa4f ]
syzkaller started to report deadlock of unix_gc_lock after commit
4090fa373f ("af_unix: Replace garbage collection algorithm."), but
it just uncovers the bug that has been there since commit 314001f0bf
("af_unix: Add OOB support").
The repro basically does the following.
from socket import *
from array import array
c1, c2 = socketpair(AF_UNIX, SOCK_STREAM)
c1.sendmsg([b'a'], [(SOL_SOCKET, SCM_RIGHTS, array("i", [c2.fileno()]))], MSG_OOB)
c2.recv(1) # blocked as no normal data in recv queue
c2.close() # done async and unblock recv()
c1.close() # done async and trigger GC
A socket sends its file descriptor to itself as OOB data and tries to
receive normal data, but finally recv() fails due to async close().
The problem here is wrong handling of OOB skb in manage_oob(). When
recvmsg() is called without MSG_OOB, manage_oob() is called to check
if the peeked skb is OOB skb. In such a case, manage_oob() pops it
out of the receive queue but does not clear unix_sock(sk)->oob_skb.
This is wrong in terms of uAPI.
Let's say we send "hello" with MSG_OOB, and "world" without MSG_OOB.
The 'o' is handled as OOB data. When recv() is called twice without
MSG_OOB, the OOB data should be lost.
>>> from socket import *
>>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM, 0)
>>> c1.send(b'hello', MSG_OOB) # 'o' is OOB data
5
>>> c1.send(b'world')
5
>>> c2.recv(5) # OOB data is not received
b'hell'
>>> c2.recv(5) # OOB date is skipped
b'world'
>>> c2.recv(5, MSG_OOB) # This should return an error
b'o'
In the same situation, TCP actually returns -EINVAL for the last
recv().
Also, if we do not clear unix_sk(sk)->oob_skb, unix_poll() always set
EPOLLPRI even though the data has passed through by previous recv().
To avoid these issues, we must clear unix_sk(sk)->oob_skb when dequeuing
it from recv queue.
The reason why the old GC did not trigger the deadlock is because the
old GC relied on the receive queue to detect the loop.
When it is triggered, the socket with OOB data is marked as GC candidate
because file refcount == inflight count (1). However, after traversing
all inflight sockets, the socket still has a positive inflight count (1),
thus the socket is excluded from candidates. Then, the old GC lose the
chance to garbage-collect the socket.
With the old GC, the repro continues to create true garbage that will
never be freed nor detected by kmemleak as it's linked to the global
inflight list. That's why we couldn't even notice the issue.
Fixes: 314001f0bf ("af_unix: Add OOB support")
Reported-by: syzbot+7f7f201cc2668a8fd169@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7f7f201cc2668a8fd169
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240405221057.2406-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 11695c6e96 ]
sk_getsockopt() runs locklessly, thus we need to annotate the read
of sk->sk_peek_off.
While we are at it, add corresponding annotations to sk_set_peek_off()
and unix_set_peek_off().
Fixes: b9bb53f383 ("sock: convert sk_peek_offset functions to WRITE_ONCE")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3ff8bff704 ]
There is a race resulting in alive SOCK_SEQPACKET socket
may change its state from TCP_ESTABLISHED to TCP_CLOSE:
unix_release_sock(peer) unix_dgram_sendmsg(sk)
sock_orphan(peer)
sock_set_flag(peer, SOCK_DEAD)
sock_alloc_send_pskb()
if !(sk->sk_shutdown & SEND_SHUTDOWN)
OK
if sock_flag(peer, SOCK_DEAD)
sk->sk_state = TCP_CLOSE
sk->sk_shutdown = SHUTDOWN_MASK
After that socket sk remains almost normal: it is able to connect, listen, accept
and recvmsg, while it can't sendmsg.
Since this is the only possibility for alive SOCK_SEQPACKET to change
the state in such way, we should better fix this strange and potentially
danger corner case.
Note, that we will return EPIPE here like this is normally done in sock_alloc_send_pskb().
Originally used ECONNREFUSED looks strange, since it's strange to return
a specific retval in dependence of race in kernel, when user can't affect on this.
Also, move TCP_CLOSE assignment for SOCK_DGRAM sockets under state lock
to fix race with unix_dgram_connect():
unix_dgram_connect(other) unix_dgram_sendmsg(sk)
unix_peer(sk) = NULL
unix_state_unlock(sk)
unix_state_double_lock(sk, other)
sk->sk_state = TCP_ESTABLISHED
unix_peer(sk) = other
unix_state_double_unlock(sk, other)
sk->sk_state = TCP_CLOSED
This patch fixes both of these races.
Fixes: 83301b5367 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
Link: https://lore.kernel.org/r/135fda25-22d5-837a-782b-ceee50e19844@ya.ru
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7a62ed6136 upstream.
syzbot reported a sequence of memory leaks, and one of them indicated we
failed to free a whole sk:
unreferenced object 0xffff8880126e0000 (size 1088):
comm "syz-executor419", pid 326, jiffies 4294773607 (age 12.609s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 7d 00 00 00 00 00 00 00 ........}.......
01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace:
[<000000006fefe750>] sk_prot_alloc+0x64/0x2a0 net/core/sock.c:1970
[<0000000074006db5>] sk_alloc+0x3b/0x800 net/core/sock.c:2029
[<00000000728cd434>] unix_create1+0xaf/0x920 net/unix/af_unix.c:928
[<00000000a279a139>] unix_create+0x113/0x1d0 net/unix/af_unix.c:997
[<0000000068259812>] __sock_create+0x2ab/0x550 net/socket.c:1516
[<00000000da1521e1>] sock_create net/socket.c:1566 [inline]
[<00000000da1521e1>] __sys_socketpair+0x1a8/0x550 net/socket.c:1698
[<000000007ab259e1>] __do_sys_socketpair net/socket.c:1751 [inline]
[<000000007ab259e1>] __se_sys_socketpair net/socket.c:1748 [inline]
[<000000007ab259e1>] __x64_sys_socketpair+0x97/0x100 net/socket.c:1748
[<000000007dedddc1>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<000000007dedddc1>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
[<000000009456679f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
We can reproduce this issue by creating two AF_UNIX SOCK_STREAM sockets,
send()ing an OOB skb to each other, and close()ing them without consuming
the OOB skbs.
int skpair[2];
socketpair(AF_UNIX, SOCK_STREAM, 0, skpair);
send(skpair[0], "x", 1, MSG_OOB);
send(skpair[1], "x", 1, MSG_OOB);
close(skpair[0]);
close(skpair[1]);
Currently, we free an OOB skb in unix_sock_destructor() which is called via
__sk_free(), but it's too late because the receiver's unix_sk(sk)->oob_skb
is accounted against the sender's sk->sk_wmem_alloc and __sk_free() is
called only when sk->sk_wmem_alloc is 0.
In the repro sequences, we do not consume the OOB skb, so both two sk's
sock_put() never reach __sk_free() due to the positive sk->sk_wmem_alloc.
Then, no one can consume the OOB skb nor call __sk_free(), and we finally
leak the two whole sk.
Thus, we must free the unconsumed OOB skb earlier when close()ing the
socket.
Fixes: 314001f0bf ("af_unix: Add OOB support")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Anil Altinay <aaltinay@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 662a80946c ]
unix_dgram_poll() calls unix_dgram_peer_wake_me() without `other`'s
lock held and check if its receive queue is full. Here we need to
use unix_recvq_full_lockless() instead of unix_recvq_full(), otherwise
KCSAN will report a data-race.
Fixes: 7d267278a9 ("unix: avoid use-after-free in ep_remove_wait_queue")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20220605232325.11804-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d9a232d435 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e82025c623 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f9390b249c ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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
Rao Shoaib