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
cmpdi2.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
*/
#include <linux/export.h>
#include <linux/libgcc.h>
word_type notrace __cmpdi2(long long a, long long b)
{
const DWunion au = {
.ll = a
};
const DWunion bu = {
.ll = b
};
if (au.s.high < bu.s.high)
return 0;
else if (au.s.high > bu.s.high)
return 2;
if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
return 0;
else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
return 2;
return 1;
}
EXPORT_SYMBOL(__cmpdi2);
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