[ Upstream commit 6bf24dc0cc0cc43b29ba344b66d78590e687e046 ]
In the if(skb_peek(arrvq) == skb) branch, it calls __skb_dequeue(arrvq) to get
the skb by skb = skb_peek(arrvq). Then __skb_dequeue() unlinks the skb from arrvq
and returns the skb which equals to skb_peek(arrvq). After __skb_dequeue(arrvq)
finished, the skb is freed by kfree_skb(__skb_dequeue(arrvq)) in the first time.
Unfortunately, the same skb is freed in the second time by kfree_skb(skb) after
the branch completed.
My patch removes kfree_skb() in the if(skb_peek(arrvq) == skb) branch, because
this skb will be freed by kfree_skb(skb) finally.
Fixes: cb1b728096f54 ("tipc: eliminate race condition at multicast reception")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 49afb806cb650dd1f06f191994f3aa657d264009 ]
When a socket is suddenly shutdown or released, it will reject all the
unreceived messages in its receive queue. This applies to a connected
socket too, whereas there is only one 'FIN' message required to be sent
back to its peer in this case.
In case there are many messages in the queue and/or some connections
with such messages are shutdown at the same time, the link layer will
easily get overflowed at the 'TIPC_SYSTEM_IMPORTANCE' backlog level
because of the message rejections. As a result, the link will be taken
down. Moreover, immediately when the link is re-established, the socket
layer can continue to reject the messages and the same issue happens...
The commit refactors the '__tipc_shutdown()' function to only send one
'FIN' in the situation mentioned above. For the connectionless case, it
is unavoidable but usually there is no rejections for such socket
messages because they are 'dest-droppable' by default.
In addition, the new code makes the other socket states clear
(e.g.'TIPC_LISTEN') and treats as a separate case to avoid misbehaving.
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a4b5cc9e10803ecba64a7d54c0f47e4564b4a980 ]
I confirmed that the problem fixed by commit 2a63866c8b51a3f7 ("tipc: fix
shutdown() of connectionless socket") also applies to stream socket.
----------
#include <sys/socket.h>
#include <unistd.h>
#include <sys/wait.h>
int main(int argc, char *argv[])
{
int fds[2] = { -1, -1 };
socketpair(PF_TIPC, SOCK_STREAM /* or SOCK_DGRAM */, 0, fds);
if (fork() == 0)
_exit(read(fds[0], NULL, 1));
shutdown(fds[0], SHUT_RDWR); /* This must make read() return. */
wait(NULL); /* To be woken up by _exit(). */
return 0;
}
----------
Since shutdown(SHUT_RDWR) should affect all processes sharing that socket,
unconditionally setting sk->sk_shutdown to SHUTDOWN_MASK will be the right
behavior.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2a63866c8b51a3f72cea388dfac259d0e14c4ba6 ]
syzbot is reporting hung task at nbd_ioctl() [1], for there are two
problems regarding TIPC's connectionless socket's shutdown() operation.
----------
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/nbd.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
const int fd = open("/dev/nbd0", 3);
alarm(5);
ioctl(fd, NBD_SET_SOCK, socket(PF_TIPC, SOCK_DGRAM, 0));
ioctl(fd, NBD_DO_IT, 0); /* To be interrupted by SIGALRM. */
return 0;
}
----------
One problem is that wait_for_completion() from flush_workqueue() from
nbd_start_device_ioctl() from nbd_ioctl() cannot be completed when
nbd_start_device_ioctl() received a signal at wait_event_interruptible(),
for tipc_shutdown() from kernel_sock_shutdown(SHUT_RDWR) from
nbd_mark_nsock_dead() from sock_shutdown() from nbd_start_device_ioctl()
is failing to wake up a WQ thread sleeping at wait_woken() from
tipc_wait_for_rcvmsg() from sock_recvmsg() from sock_xmit() from
nbd_read_stat() from recv_work() scheduled by nbd_start_device() from
nbd_start_device_ioctl(). Fix this problem by always invoking
sk->sk_state_change() (like inet_shutdown() does) when tipc_shutdown() is
called.
The other problem is that tipc_wait_for_rcvmsg() cannot return when
tipc_shutdown() is called, for tipc_shutdown() sets sk->sk_shutdown to
SEND_SHUTDOWN (despite "how" is SHUT_RDWR) while tipc_wait_for_rcvmsg()
needs sk->sk_shutdown set to RCV_SHUTDOWN or SHUTDOWN_MASK. Fix this
problem by setting sk->sk_shutdown to SHUTDOWN_MASK (like inet_shutdown()
does) when the socket is connectionless.
[1] https://syzkaller.appspot.com/bug?id=3fe51d307c1f0a845485cf1798aa059d12bf18b2
Reported-by: syzbot <syzbot+e36f41d207137b5d12f7@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lv Yunlong