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>
1 parent e13ad14
warm-plug-howto.rst
===================
IDE warm-plug HOWTO
===================
To warm-plug devices on a port 'idex'::
# echo -n "1" > /sys/class/ide_port/idex/delete_devices
unplug old device(s) and plug new device(s)::
# echo -n "1" > /sys/class/ide_port/idex/scan
done
NOTE: please make sure that partitions are unmounted and that there are
no other active references to devices before doing "delete_devices" step,
also do not attempt "scan" step on devices currently in use -- otherwise
results may be unpredictable and lead to data loss if you're unlucky
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