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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 
net_sched: check error pointer in tcf_dump_walker()
 
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
test_debug_virtual.c 
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/sizes.h>
#include <linux/io.h>

#include <asm/page.h>
#ifdef CONFIG_MIPS
#include <asm/bootinfo.h>
#endif

struct foo {
	unsigned int bar;
};

static struct foo *foo;

static int __init test_debug_virtual_init(void)
{
	phys_addr_t pa;
	void *va;

	va = (void *)VMALLOC_START;
	pa = virt_to_phys(va);

	pr_info("PA: %pa for VA: 0x%lx\n", &pa, (unsigned long)va);

	foo = kzalloc(sizeof(*foo), GFP_KERNEL);
	if (!foo)
		return -ENOMEM;

	pa = virt_to_phys(foo);
	va = foo;
	pr_info("PA: %pa for VA: 0x%lx\n", &pa, (unsigned long)va);

	return 0;
}
module_init(test_debug_virtual_init);

static void __exit test_debug_virtual_exit(void)
{
	kfree(foo);
}
module_exit(test_debug_virtual_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Test module for CONFIG_DEBUG_VIRTUAL");
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