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  1. 06 Apr, 2022 6 commits
    • Alexander Aring's avatar
      dlm: rearrange async condition return · a800ba77
      Alexander Aring authored 
      This patch moves the return of FILE_LOCK_DEFERRED a little bit earlier
than checking afterwards again if the request was an asynchronous request.
Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      a800ba77
    • Alexander Aring's avatar
      dlm: cleanup plock_op vs plock_xop · bcbb4ba6
      Alexander Aring authored 
      Lately the different casting between plock_op and plock_xop and list
holders which was involved showed some issues which were hard to see.
This patch removes the "plock_xop" structure and introduces a
"struct plock_async_data". This structure will be set in "struct plock_op"
in case of asynchronous lock handling as the original "plock_xop" was
made for. There is no need anymore to cast pointers around for
additional fields in case of asynchronous lock handling.  As disadvantage
another allocation was introduces but only needed in the asynchronous
case which is currently only used in combination with nfs lockd.
Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      bcbb4ba6
    • Alexander Aring's avatar
      dlm: replace sanity checks with WARN_ON · a559790c
      Alexander Aring authored 
      There are several sanity checks and recover handling if they occur in
the dlm plock handling. From my understanding those operation can't run
in parallel with any list manipulation which involved setting the list
holder of plock_op, if so we have a bug which this sanity check will
warn about. Previously if such sanity check occurred the dlm plock
handling was trying to recover from it by deleting the plock_op from a
list which the holder was set to. However there is a bug in the dlm
plock handling if this case ever happens. To make such bugs are more
visible for further investigations we add a WARN_ON() on those sanity
checks and remove the recovering handling because other possible side
effects.
Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      a559790c
    • Alexander Aring's avatar
      dlm: fix plock invalid read · 42252d0d
      Alexander Aring authored 
      This patch fixes an invalid read showed by KASAN. A unlock will allocate a
"struct plock_op" and a followed send_op() will append it to a global
send_list data structure. In some cases a followed dev_read() moves it
to recv_list and dev_write() will cast it to "struct plock_xop" and access
fields which are only available in those structures. At this point an
invalid read happens by accessing those fields.

To fix this issue the "callback" field is moved to "struct plock_op" to
indicate that a cast to "plock_xop" is allowed and does the additional
"plock_xop" handling if set.

Example of the KASAN output which showed the invalid read:

[ 2064.296453] ==================================================================
[ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm]
[ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484
[ 2064.308168]
[ 2064.308575] CPU: 0 PID: 7484 Comm: dlm_controld Kdump: loaded Not tainted 5.14.0+ #9
[ 2064.310292] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 2064.311618] Call Trace:
[ 2064.312218]  dump_stack_lvl+0x56/0x7b
[ 2064.313150]  print_address_description.constprop.8+0x21/0x150
[ 2064.314578]  ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.315610]  ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.316595]  kasan_report.cold.14+0x7f/0x11b
[ 2064.317674]  ? dev_write+0x52b/0x5a0 [dlm]
[ 2064.318687]  dev_write+0x52b/0x5a0 [dlm]
[ 2064.319629]  ? dev_read+0x4a0/0x4a0 [dlm]
[ 2064.320713]  ? bpf_lsm_kernfs_init_security+0x10/0x10
[ 2064.321926]  vfs_write+0x17e/0x930
[ 2064.322769]  ? __fget_light+0x1aa/0x220
[ 2064.323753]  ksys_write+0xf1/0x1c0
[ 2064.324548]  ? __ia32_sys_read+0xb0/0xb0
[ 2064.325464]  do_syscall_64+0x3a/0x80
[ 2064.326387]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2064.327606] RIP: 0033:0x7f807e4ba96f
[ 2064.328470] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 87 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 87 f8 ff 48
[ 2064.332902] RSP: 002b:00007ffd50cfe6e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 2064.334658] RAX: ffffffffffffffda RBX: 000055cc3886eb30 RCX: 00007f807e4ba96f
[ 2064.336275] RDX: 0000000000000040 RSI: 00007ffd50cfe7e0 RDI: 0000000000000010
[ 2064.337980] RBP: 00007ffd50cfe7e0 R08: 0000000000000000 R09: 0000000000000001
[ 2064.339560] R10: 000055cc3886eb30 R11: 0000000000000293 R12: 000055cc3886eb80
[ 2064.341237] R13: 000055cc3886eb00 R14: 000055cc3886f590 R15: 0000000000000001
[ 2064.342857]
[ 2064.343226] Allocated by task 12438:
[ 2064.344057]  kasan_save_stack+0x1c/0x40
[ 2064.345079]  __kasan_kmalloc+0x84/0xa0
[ 2064.345933]  kmem_cache_alloc_trace+0x13b/0x220
[ 2064.346953]  dlm_posix_unlock+0xec/0x720 [dlm]
[ 2064.348811]  do_lock_file_wait.part.32+0xca/0x1d0
[ 2064.351070]  fcntl_setlk+0x281/0xbc0
[ 2064.352879]  do_fcntl+0x5e4/0xfe0
[ 2064.354657]  __x64_sys_fcntl+0x11f/0x170
[ 2064.356550]  do_syscall_64+0x3a/0x80
[ 2064.358259]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2064.360745]
[ 2064.361511] Last potentially related work creation:
[ 2064.363957]  kasan_save_stack+0x1c/0x40
[ 2064.365811]  __kasan_record_aux_stack+0xaf/0xc0
[ 2064.368100]  call_rcu+0x11b/0xf70
[ 2064.369785]  dlm_process_incoming_buffer+0x47d/0xfd0 [dlm]
[ 2064.372404]  receive_from_sock+0x290/0x770 [dlm]
[ 2064.374607]  process_recv_sockets+0x32/0x40 [dlm]
[ 2064.377290]  process_one_work+0x9a8/0x16e0
[ 2064.379357]  worker_thread+0x87/0xbf0
[ 2064.381188]  kthread+0x3ac/0x490
[ 2064.383460]  ret_from_fork+0x22/0x30
[ 2064.385588]
[ 2064.386518] Second to last potentially related work creation:
[ 2064.389219]  kasan_save_stack+0x1c/0x40
[ 2064.391043]  __kasan_record_aux_stack+0xaf/0xc0
[ 2064.393303]  call_rcu+0x11b/0xf70
[ 2064.394885]  dlm_process_incoming_buffer+0x47d/0xfd0 [dlm]
[ 2064.397694]  receive_from_sock+0x290/0x770 [dlm]
[ 2064.399932]  process_recv_sockets+0x32/0x40 [dlm]
[ 2064.402180]  process_one_work+0x9a8/0x16e0
[ 2064.404388]  worker_thread+0x87/0xbf0
[ 2064.406124]  kthread+0x3ac/0x490
[ 2064.408021]  ret_from_fork+0x22/0x30
[ 2064.409834]
[ 2064.410599] The buggy address belongs to the object at ffff88800ef22780
[ 2064.410599]  which belongs to the cache kmalloc-96 of size 96
[ 2064.416495] The buggy address is located 88 bytes inside of
[ 2064.416495]  96-byte region [ffff88800ef22780, ffff88800ef227e0)
[ 2064.422045] The buggy address belongs to the page:
[ 2064.424635] page:00000000b6bef8bc refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xef22
[ 2064.428970] flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff)
[ 2064.432515] raw: 000fffffc0000200 ffffea0000d68b80 0000001400000014 ffff888001041780
[ 2064.436110] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
[ 2064.439813] page dumped because: kasan: bad access detected
[ 2064.442548]
[ 2064.443310] Memory state around the buggy address:
[ 2064.445988]  ffff88800ef22680: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2064.449444]  ffff88800ef22700: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2064.452941] >ffff88800ef22780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
[ 2064.456383]                                                     ^
[ 2064.459386]  ffff88800ef22800: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
[ 2064.462788]  ffff88800ef22880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
[ 2064.466239] ==================================================================

reproducer in python:

import argparse
import struct
import fcntl
import os

parser = argparse.ArgumentParser()

parser.add_argument('-f', '--file',
		    help='file to use fcntl, must be on dlm lock filesystem e.g. gfs2')

args = parser.parse_args()

f = open(args.file, 'wb+')

lockdata = struct.pack('hhllhh', fcntl.F_WRLCK,0,0,0,0,0)
fcntl.fcntl(f, fcntl.F_SETLK, lockdata)
lockdata = struct.pack('hhllhh', fcntl.F_UNLCK,0,0,0,0,0)
fcntl.fcntl(f, fcntl.F_SETLK, lockdata)

Fixes: 586759f0 ("gfs2: nfs lock support for gfs2")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      42252d0d
    • Alexander Aring's avatar
      dlm: fix missing check in validate_lock_args · 67e4d8c5
      Alexander Aring authored 
      This patch adds a additional check if lkb->lkb_wait_count is non zero as
it is done in validate_unlock_args() to check if any operation is in
progress. While on it add a comment taken from validate_unlock_args() to
signal what the check is doing.

There might be no changes because if lkb->lkb_wait_type is non zero
implies that lkb->lkb_wait_count is non zero. However we should add the
check as it does validate_unlock_args().
Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      67e4d8c5
    • Dan Carpenter's avatar
      dlm: uninitialized variable on error in dlm_listen_for_all() · 1f4f1084
      Dan Carpenter authored 
      The "sock" variable is not initialized on this error path.

Cc: stable@vger.kernel.org
Fixes: 2dc6b115 ("fs: dlm: introduce generic listen")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      1f4f1084
  3. 03 Apr, 2022 8 commits
  5. 02 Apr, 2022 26 commits
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