Fabio M. De Francesco 062772d5cc net/smc: Use a mutex for locking "struct smc_pnettable"
commit 7ff57e98fb78ad94edafbdc7435f2d745e9e6bb5 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:47:59 +01:00
..
2021-06-30 15:51:09 -07:00
2021-06-29 11:28:21 -07:00
2021-05-26 07:03:39 +02:00
2021-08-05 13:27:50 +01:00
2021-06-03 15:13:56 -07:00
2021-07-29 15:06:49 +01:00
2021-07-29 15:06:49 +01:00