Revision 88956eabfdea7d01d550535af120d4ef265b1d02 authored by NeilBrown on 12 September 2023, 01:25:00 UTC, committed by Chuck Lever on 12 September 2023, 13:39:35 UTC
If /proc/fs/nfsd/pool_stats is open when the last nfsd thread exits, then
when the file is closed a NULL pointer is dereferenced.
This is because nfsd_pool_stats_release() assumes that the
pointer to the svc_serv cannot become NULL while a reference is held.

This used to be the case but a recent patch split nfsd_last_thread() out
from nfsd_put(), and clearing the pointer is done in nfsd_last_thread().

This is easily reproduced by running
   rpc.nfsd 8 ; ( rpc.nfsd 0;true) < /proc/fs/nfsd/pool_stats

Fortunately nfsd_pool_stats_release() has easy access to the svc_serv
pointer, and so can call svc_put() on it directly.

Fixes: 9f28a971ee9f ("nfsd: separate nfsd_last_thread() from nfsd_put()")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
1 parent fdd2630
Raw File
bitmap.h
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * bitmap.h - Defines for NTFS kernel bitmap handling.  Part of the Linux-NTFS
 *	      project.
 *
 * Copyright (c) 2004 Anton Altaparmakov
 */

#ifndef _LINUX_NTFS_BITMAP_H
#define _LINUX_NTFS_BITMAP_H

#ifdef NTFS_RW

#include <linux/fs.h>

#include "types.h"

extern int __ntfs_bitmap_set_bits_in_run(struct inode *vi, const s64 start_bit,
		const s64 count, const u8 value, const bool is_rollback);

/**
 * ntfs_bitmap_set_bits_in_run - set a run of bits in a bitmap to a value
 * @vi:			vfs inode describing the bitmap
 * @start_bit:		first bit to set
 * @count:		number of bits to set
 * @value:		value to set the bits to (i.e. 0 or 1)
 *
 * Set @count bits starting at bit @start_bit in the bitmap described by the
 * vfs inode @vi to @value, where @value is either 0 or 1.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_bitmap_set_bits_in_run(struct inode *vi,
		const s64 start_bit, const s64 count, const u8 value)
{
	return __ntfs_bitmap_set_bits_in_run(vi, start_bit, count, value,
			false);
}

/**
 * ntfs_bitmap_set_run - set a run of bits in a bitmap
 * @vi:		vfs inode describing the bitmap
 * @start_bit:	first bit to set
 * @count:	number of bits to set
 *
 * Set @count bits starting at bit @start_bit in the bitmap described by the
 * vfs inode @vi.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_bitmap_set_run(struct inode *vi, const s64 start_bit,
		const s64 count)
{
	return ntfs_bitmap_set_bits_in_run(vi, start_bit, count, 1);
}

/**
 * ntfs_bitmap_clear_run - clear a run of bits in a bitmap
 * @vi:		vfs inode describing the bitmap
 * @start_bit:	first bit to clear
 * @count:	number of bits to clear
 *
 * Clear @count bits starting at bit @start_bit in the bitmap described by the
 * vfs inode @vi.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_bitmap_clear_run(struct inode *vi, const s64 start_bit,
		const s64 count)
{
	return ntfs_bitmap_set_bits_in_run(vi, start_bit, count, 0);
}

/**
 * ntfs_bitmap_set_bit - set a bit in a bitmap
 * @vi:		vfs inode describing the bitmap
 * @bit:	bit to set
 *
 * Set bit @bit in the bitmap described by the vfs inode @vi.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_bitmap_set_bit(struct inode *vi, const s64 bit)
{
	return ntfs_bitmap_set_run(vi, bit, 1);
}

/**
 * ntfs_bitmap_clear_bit - clear a bit in a bitmap
 * @vi:		vfs inode describing the bitmap
 * @bit:	bit to clear
 *
 * Clear bit @bit in the bitmap described by the vfs inode @vi.
 *
 * Return 0 on success and -errno on error.
 */
static inline int ntfs_bitmap_clear_bit(struct inode *vi, const s64 bit)
{
	return ntfs_bitmap_clear_run(vi, bit, 1);
}

#endif /* NTFS_RW */

#endif /* defined _LINUX_NTFS_BITMAP_H */
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