Revision 580e4273d7a883ececfefa692c1f96bdbacb99b5 authored by Cong Wang on 02 October 2020, 19:13:34 UTC, committed by David S. Miller on 04 October 2020, 21:53:06 UTC
Although we take RTNL on dump path, it is possible to
skip RTNL on insertion path. So the following race condition
is possible:

rtnl_lock()		// no rtnl lock
			mutex_lock(&idrinfo->lock);
			// insert ERR_PTR(-EBUSY)
			mutex_unlock(&idrinfo->lock);
tc_dump_action()
rtnl_unlock()

So we have to skip those temporary -EBUSY entries on dump path
too.

Reported-and-tested-by: syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com
Fixes: 0fedc63fadf0 ("net_sched: commit action insertions together")
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 9a9e774
Raw File
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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