Revision 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 authored by Fabio M. De Francesco on 23 February 2022, 10:02:52 UTC, committed by Jakub Kicinski on 24 February 2022, 17:09:33 UTC
smc_pnetid_by_table_ib() uses read_lock() and then it calls smc_pnet_apply_ib()
which, in turn, calls mutex_lock(&smc_ib_devices.mutex).

read_lock() disables preemption. Therefore, the code acquires a mutex while in
atomic context and it leads to a SAC bug.

Fix this bug by replacing the rwlock with a mutex.

Reported-and-tested-by: syzbot+4f322a6d84e991c38775@syzkaller.appspotmail.com
Fixes: 64e28b52c7a6 ("net/smc: add pnet table namespace support")
Confirmed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20220223100252.22562-1-fmdefrancesco@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Raw File
secid.rst
.. SPDX-License-Identifier: GPL-2.0

=================
LSM/SeLinux secid
=================

flowi structure:

The secid member in the flow structure is used in LSMs (e.g. SELinux) to indicate
the label of the flow. This label of the flow is currently used in selecting
matching labeled xfrm(s).

If this is an outbound flow, the label is derived from the socket, if any, or
the incoming packet this flow is being generated as a response to (e.g. tcp
resets, timewait ack, etc.). It is also conceivable that the label could be
derived from other sources such as process context, device, etc., in special
cases, as may be appropriate.

If this is an inbound flow, the label is derived from the IPSec security
associations, if any, used by the packet.
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