c25546cac3
commit 4c0288299fd09ee7c6fbe2f57421f314d8c981db upstream.
The MPTCP protocol does not expect that any other entity could change
the first subflow status when such socket is listening.
Unfortunately the TCP diag interface allows aborting any TCP socket,
including MPTCP listeners subflows. As reported by syzbot, that trigger
a WARN() and could lead to later bigger trouble.
The MPTCP protocol needs to do some MPTCP-level cleanup actions to
properly shutdown the listener. To keep the fix simple, prevent
entirely the diag interface from stopping such listeners.
We could refine the diag callback in a later, larger patch targeting
net-next.
Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: stable@vger.kernel.org
Reported-by: <syzbot+5a01c3a666e726bc8752@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/netdev/0000000000004f4579060c68431b@google.com/
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20231226-upstream-net-20231226-mptcp-prevent-warn-v1-2-1404dcc431ea@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.