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Revision 84811412464d66fcf73661a279aa1d7985166495 authored by Prashant Malani on 20 November 2019, 19:40:21 UTC, committed by David S. Miller on 20 November 2019, 20:48:13 UTC 
r8152: Re-order napi_disable in rtl8152_close
 
Both rtl_work_func_t() and rtl8152_close() call napi_disable().
Since the two calls aren't protected by a lock, if the close
function starts executing before the work function, we can get into a
situation where the napi_disable() function is called twice in
succession (first by rtl8152_close(), then by set_carrier()).

In such a situation, the second call would loop indefinitely, since
rtl8152_close() doesn't call napi_enable() to clear the NAPI_STATE_SCHED
bit.

The rtl8152_close() function in turn issues a
cancel_delayed_work_sync(), and so it would wait indefinitely for the
rtl_work_func_t() to complete. Since rtl8152_close() is called by a
process holding rtnl_lock() which is requested by other processes, this
eventually leads to a system deadlock and crash.

Re-order the napi_disable() call to occur after the work function
disabling and urb cancellation calls are issued.

Change-Id: I6ef0b703fc214998a037a68f722f784e1d07815e
Reported-by: http://crbug.com/1017928
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent b172845
Raw File
symlink.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
 */

#include "autofs_i.h"

static const char *autofs_get_link(struct dentry *dentry,
				   struct inode *inode,
				   struct delayed_call *done)
{
	struct autofs_sb_info *sbi;
	struct autofs_info *ino;

	if (!dentry)
		return ERR_PTR(-ECHILD);
	sbi = autofs_sbi(dentry->d_sb);
	ino = autofs_dentry_ino(dentry);
	if (ino && !autofs_oz_mode(sbi))
		ino->last_used = jiffies;
	return d_inode(dentry)->i_private;
}

const struct inode_operations autofs_symlink_inode_operations = {
	.get_link	= autofs_get_link
};
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