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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 
NFSD: fix possible oops when nfsd/pool_stats is closed.
 
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
initramfs_data.S 
/* SPDX-License-Identifier: GPL-2.0 */
/*
  initramfs_data includes the compressed binary that is the
  filesystem used for early user space.
  Note: Older versions of "as" (prior to binutils 2.11.90.0.23
  released on 2001-07-14) dit not support .incbin.
  If you are forced to use older binutils than that then the
  following trick can be applied to create the resulting binary:


  ld -m elf_i386  --format binary --oformat elf32-i386 -r \
  -T initramfs_data.scr initramfs_data.cpio.gz -o initramfs_data.o
   ld -m elf_i386  -r -o built-in.a initramfs_data.o

  For including the .init.ramfs sections, see include/asm-generic/vmlinux.lds.

  The above example is for i386 - the parameters vary from architectures.
  Eventually look up LDFLAGS_BLOB in an older version of the
  arch/$(ARCH)/Makefile to see the flags used before .incbin was introduced.

  Using .incbin has the advantage over ld that the correct flags are set
  in the ELF header, as required by certain architectures.
*/

.section .init.ramfs,"a"
__irf_start:
.incbin "usr/initramfs_inc_data"
__irf_end:
.section .init.ramfs.info,"a"
.globl __initramfs_size
__initramfs_size:
#ifdef CONFIG_64BIT
	.quad __irf_end - __irf_start
#else
	.long __irf_end - __irf_start
#endif
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