linux/fs/gfs2
Andreas Gruenbacher f66af88e33 gfs2: Stop using gfs2_make_fs_ro for withdraw
[   81.372851][ T5532] CPU: 1 PID: 5532 Comm: syz-executor.0 Not tainted 6.2.0-rc1-syzkaller-dirty #0
[   81.382080][ T5532] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
[   81.392343][ T5532] Call Trace:
[   81.395654][ T5532]  <TASK>
[   81.398603][ T5532]  dump_stack_lvl+0x1b1/0x290
[   81.418421][ T5532]  gfs2_assert_warn_i+0x19a/0x2e0
[   81.423480][ T5532]  gfs2_quota_cleanup+0x4c6/0x6b0
[   81.428611][ T5532]  gfs2_make_fs_ro+0x517/0x610
[   81.457802][ T5532]  gfs2_withdraw+0x609/0x1540
[   81.481452][ T5532]  gfs2_inode_refresh+0xb2d/0xf60
[   81.506658][ T5532]  gfs2_instantiate+0x15e/0x220
[   81.511504][ T5532]  gfs2_glock_wait+0x1d9/0x2a0
[   81.516352][ T5532]  do_sync+0x485/0xc80
[   81.554943][ T5532]  gfs2_quota_sync+0x3da/0x8b0
[   81.559738][ T5532]  gfs2_sync_fs+0x49/0xb0
[   81.564063][ T5532]  sync_filesystem+0xe8/0x220
[   81.568740][ T5532]  generic_shutdown_super+0x6b/0x310
[   81.574112][ T5532]  kill_block_super+0x79/0xd0
[   81.578779][ T5532]  deactivate_locked_super+0xa7/0xf0
[   81.584064][ T5532]  cleanup_mnt+0x494/0x520
[   81.593753][ T5532]  task_work_run+0x243/0x300
[   81.608837][ T5532]  exit_to_user_mode_loop+0x124/0x150
[   81.614232][ T5532]  exit_to_user_mode_prepare+0xb2/0x140
[   81.619820][ T5532]  syscall_exit_to_user_mode+0x26/0x60
[   81.625287][ T5532]  do_syscall_64+0x49/0xb0
[   81.629710][ T5532]  entry_SYSCALL_64_after_hwframe+0x63/0xcd

In this backtrace, gfs2_quota_sync() takes quota data references and
then calls do_sync().  Function do_sync() encounters filesystem
corruption and withdraws the filesystem, which (among other things) calls
gfs2_quota_cleanup().  Function gfs2_quota_cleanup() wrongly assumes
that nobody is holding any quota data references anymore, and destroys
all quota data objects.  When gfs2_quota_sync() then resumes and
dereferences the quota data objects it is holding, those objects are no
longer there.

Function gfs2_quota_cleanup() deals with resource deallocation and can
easily be delayed until gfs2_put_super() in the case of a filesystem
withdraw.  In fact, most of the other work gfs2_make_fs_ro() does is
unnecessary during a withdraw as well, so change signal_our_withdraw()
to skip gfs2_make_fs_ro() and perform the necessary steps directly
instead.

Thanks to Edward Adam Davis <eadavis@sina.com> for the initial patches.

Link: https://lore.kernel.org/all/0000000000002b5e2405f14e860f@google.com
Reported-by: syzbot+3f6a670108ce43356017@syzkaller.appspotmail.com
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2023-09-05 15:58:17 +02:00
..
acl.c fs: port acl to mnt_idmap 2023-01-19 09:24:28 +01:00
acl.h fs: port ->set_acl() to pass mnt_idmap 2023-01-19 09:24:27 +01:00
aops.c gfs2: low-memory forced flush fixes 2023-09-05 15:58:16 +02:00
aops.h gfs2: support ludicrously large folios in gfs2_trans_add_databufs() 2023-06-19 16:19:30 -07:00
bmap.c gfs: Don't use GFP_NOFS in gfs2_unstuff_dinode 2023-09-05 15:58:16 +02:00
bmap.h gfs2: Eliminate gfs2_trim_blocks 2023-04-18 14:40:12 +02:00
dentry.c Reinstate "GFS2: free disk inode which is deleted by remote node -V2" 2023-03-23 19:37:56 +01:00
dir.c gfs2 fixes 2022-08-06 14:44:49 -07:00
dir.h gfs2: Delete an unnecessary check before brelse() 2019-09-04 20:22:17 +02:00
export.c Change calling conventions for filldir_t 2022-08-17 17:25:04 -04:00
file.c gfs2: Don't use filemap_splice_read 2023-08-07 18:42:04 +02:00
gfs2.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
glock.c gfs2: Rename SDF_DEACTIVATING to SDF_KILL 2023-09-05 15:58:16 +02:00
glock.h gfs2: Remove LM_FLAG_PRIORITY flag 2023-09-05 15:58:16 +02:00
glops.c gfs2: Rename SDF_DEACTIVATING to SDF_KILL 2023-09-05 15:58:16 +02:00
glops.h gfs2: Split up gfs2_meta_sync into inode and rgrp versions 2020-10-29 22:16:46 +01:00
incore.h gfs2: Rename SDF_DEACTIVATING to SDF_KILL 2023-09-05 15:58:16 +02:00
inode.c gfs2: Use mapping->gfp_mask for metadata inodes 2023-09-05 15:58:15 +02:00
inode.h fs: port ->permission() to pass mnt_idmap 2023-01-19 09:24:28 +01:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
lock_dlm.c gfs2: Remove LM_FLAG_PRIORITY flag 2023-09-05 15:58:16 +02:00
log.c gfs2: journal flush threshold fixes and cleanup 2023-09-05 15:58:16 +02:00
log.h fs/gfs2: Use the enum req_op and blk_opf_t types 2022-07-14 12:14:32 -06:00
lops.c gfs2: Use mapping->gfp_mask for metadata inodes 2023-09-05 15:58:15 +02:00
lops.h fs/gfs2: Use the enum req_op and blk_opf_t types 2022-07-14 12:14:32 -06:00
main.c gfs2: Register fs after creating workqueues 2022-09-20 17:53:54 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
meta_io.c gfs2: replace obvious uses of b_page with b_folio 2023-01-18 17:12:40 -08:00
meta_io.h gfs2: Use container_of() for gfs2_glock(aspace) 2022-05-24 21:29:14 +02:00
ops_fstype.c gfs2: Rename SDF_DEACTIVATING to SDF_KILL 2023-09-05 15:58:16 +02:00
quota.c gfs2: Free quota data objects synchronously 2023-09-05 15:58:17 +02:00
quota.h gfs2: move privileged user check to gfs2_quota_lock_check 2020-05-08 18:47:58 +02:00
recovery.c gfs2: Replace sd_freeze_state with SDF_FROZEN flag 2023-07-03 22:30:23 +02:00
recovery.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
rgrp.c gfs2: Update rl_unlinked before releasing rgrp lock 2023-06-06 18:35:06 +02:00
rgrp.h Merge part of branch 'for-next.instantiate' into for-next 2022-08-05 18:37:03 +02:00
super.c gfs2: Stop using gfs2_make_fs_ro for withdraw 2023-09-05 15:58:17 +02:00
super.h gfs2: Rework freeze / thaw logic 2023-07-03 22:25:02 +02:00
sys.c gfs2: Rename SDF_DEACTIVATING to SDF_KILL 2023-09-05 15:58:16 +02:00
sys.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
trace_gfs2.h gfs2: Remove 'first' trace_gfs2_promote argument 2021-10-25 08:42:19 +02:00
trans.c gfs2: Fix freeze consistency check in gfs2_trans_add_meta 2023-08-07 18:40:51 +02:00
trans.h Merge branches 'rgrp-glock-sharing' and 'gfs2-revoke' from https://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git 2021-02-23 18:54:22 +01:00
util.c gfs2: Stop using gfs2_make_fs_ro for withdraw 2023-09-05 15:58:17 +02:00
util.h gfs2: gfs2_freeze_lock_shared cleanup 2023-07-03 22:30:26 +02:00
xattr.c fs: drop unused posix acl handlers 2023-03-06 09:57:12 +01:00
xattr.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00