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After introducing CLOSE_RANGE_CLOEXEC syzbot reported a crash when
CLOSE_RANGE_CLOEXEC is specified in conjunction with CLOSE_RANGE_UNSHARE.
When CLOSE_RANGE_UNSHARE is specified the caller will receive a private
file descriptor table in case their file descriptor table is currently
shared.
For the case where the caller has requested all file descriptors to be
actually closed via e.g. close_range(3, ~0U, 0) the kernel knows that
the caller does not need any of the file descriptors anymore and will
optimize the close operation by only copying all files in the range from
0 to 3 and no others.
However, if the caller requested CLOSE_RANGE_CLOEXEC together with
CLOSE_RANGE_UNSHARE the caller wants to still make use of the file
descriptors so the kernel needs to copy all of them and can't optimize.
The original patch didn't account for this and thus could cause oopses
as evidenced by the syzbot report because it assumed that all fds had
been copied. Fix this by handling the CLOSE_RANGE_CLOEXEC case.
syzbot reported
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: null-ptr-deref in atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
BUG: KASAN: null-ptr-deref in atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
BUG: KASAN: null-ptr-deref in filp_close+0x22/0x170 fs/open.c:1274
Read of size 8 at addr 0000000000000077 by task syz-executor511/8522
CPU: 1 PID: 8522 Comm: syz-executor511 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x107/0x163 lib/dump_stack.c:120
__kasan_report mm/kasan/report.c:549 [inline]
kasan_report.cold+0x5/0x37 mm/kasan/report.c:562
check_memory_region_inline mm/kasan/generic.c:186 [inline]
check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
instrument_atomic_read include/linux/instrumented.h:71 [inline]
atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
filp_close+0x22/0x170 fs/open.c:1274
close_files fs/file.c:402 [inline]
put_files_struct fs/file.c:417 [inline]
put_files_struct+0x1cc/0x350 fs/file.c:414
exit_files+0x12a/0x170 fs/file.c:435
do_exit+0xb4f/0x2a00 kernel/exit.c:818
do_group_exit+0x125/0x310 kernel/exit.c:920
get_signal+0x428/0x2100 kernel/signal.c:2792
arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
handle_signal_work kernel/entry/common.c:147 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x447039
Code: Unable to access opcode bytes at RIP 0x44700f.
RSP: 002b:00007f1b1225cdb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00000000006dbc28 RCX: 0000000000447039
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000006dbc2c
RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 00007fff223b6bef R14: 00007f1b1225d9c0 R15: 00000000006dbc2c
==================================================================
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: syzbot+96cfd2b22b3213646a93@syzkaller.appspotmail.com
Tested on:
commit: 10f7cddd selftests/core: add regression test for CLOSE_RAN..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git vfs
kernel config: https://syzkaller.appspot.com/x/.config?x=5d42216b510180e3
dashboard link: https://syzkaller.appspot.com/bug?extid=96cfd2b22b3213646a93
compiler: gcc (GCC) 10.1.0-syz 20200507
Reported-by: syzbot+96cfd2b22b3213646a93@syzkaller.appspotmail.com
Fixes: 582f1fb6b721 ("fs, close_range: add flag CLOSE_RANGE_CLOEXEC")
Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20201217213303.722643-1-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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Doing vectored buf-select read with 0 iovec passed is meaningless and
utterly broken, forbid it.
Cc: <stable@vger.kernel.org> # 5.7+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Fix passing of the additional security info via version
operations. Force new open when getting SACL and avoid
reuse of files that were previously open without
sufficient privileges to access SACLs.
Signed-off-by: Boris Protopopov <pboris@amazon.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Pull xfs updates from Darrick Wong:
"In this release we add the ability to set a 'needsrepair' flag
indicating that we /know/ the filesystem requires xfs_repair, but
other than that, it's the usual strengthening of metadata validation
and miscellaneous cleanups.
Summary:
- Introduce a "needsrepair" "feature" to flag a filesystem as needing
a pass through xfs_repair. This is key to enabling filesystem
upgrades (in xfs_db) that require xfs_repair to make minor
adjustments to metadata.
- Refactor parameter checking of recovered log intent items so that
we actually use the same validation code as them that generate the
intent items.
- Various fixes to online scrub not reacting correctly to directory
entries pointing to inodes that cannot be igetted.
- Refactor validation helpers for data and rt volume extents.
- Refactor XFS_TRANS_DQ_DIRTY out of existence.
- Fix a longstanding bug where mounting with "uqnoenforce" would
start user quotas in non-enforcing mode but /proc/mounts would
display "usrquota", implying that they are being enforced.
- Don't flag dax+reflink inodes as corruption since that is a valid
(but not fully functional) combination right now.
- Clean up raid stripe validation functions.
- Refactor the inode allocation code to be more straightforward.
- Small prep cleanup for idmapping support.
- Get rid of the xfs_buf_t typedef"
* tag 'xfs-5.11-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (40 commits)
xfs: remove xfs_buf_t typedef
fs/xfs: convert comma to semicolon
xfs: open code updating i_mode in xfs_set_acl
xfs: remove xfs_vn_setattr_nonsize
xfs: kill ialloced in xfs_dialloc()
xfs: spilt xfs_dialloc() into 2 functions
xfs: move xfs_dialloc_roll() into xfs_dialloc()
xfs: move on-disk inode allocation out of xfs_ialloc()
xfs: introduce xfs_dialloc_roll()
xfs: convert noroom, okalloc in xfs_dialloc() to bool
xfs: don't catch dax+reflink inodes as corruption in verifier
xfs: fix the forward progress assertion in xfs_iwalk_run_callbacks
xfs: remove unneeded return value check for *init_cursor()
xfs: introduce xfs_validate_stripe_geometry()
xfs: show the proper user quota options
xfs: remove the unused XFS_B_FSB_OFFSET macro
xfs: remove unnecessary null check in xfs_generic_create
xfs: directly return if the delta equal to zero
xfs: check tp->t_dqinfo value instead of the XFS_TRANS_DQ_DIRTY flag
xfs: delete duplicated tp->t_dqinfo null check and allocation
...
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Add SYSTEM_SECURITY access flag and use with smb2 when opening
files for getting/setting SACLs. Add "system.cifs_ntsd_full"
extended attribute to allow user-space access to the functionality.
Avoid multiple server calls when setting owner, DACL, and SACL.
Signed-off-by: Boris Protopopov <pboris@amazon.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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The purpose of io_uring_cancel_files() is to wait for all requests
matching ->files to go/be cancelled. We should first drop files of a
request in io_req_drop_files() and only then make it undiscoverable for
io_uring_cancel_files.
First drop, then delete from list. It's ok to leave req->id->files
dangling, because it's not dereferenced by cancellation code, only
compared against. It would potentially go to sleep and be awaken by
following in io_req_drop_files() wake_up().
Fixes: 0f2122045b946 ("io_uring: don't rely on weak ->files references")
Cc: <stable@vger.kernel.org> # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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For the first time a req punted to io-wq, we'll initialize io_wq_work's
list to be NULL, then insert req to io_wqe->work_list. If this req is not
inserted into tail of io_wqe->work_list, this req's io_wq_work list will
point to another req's io_wq_work. For splitted bio case, this req maybe
inserted to io_wqe->work_list repeatedly, once we insert it to tail of
io_wqe->work_list for the second time, now io_wq_work->list->next will be
invalid pointer, which then result in many strang error, panic, kernel
soft-lockup, rcu stall, etc.
In my vm, kernel doest not have commit cc29e1bf0d63f7 ("block: disable
iopoll for split bio"), below fio job can reproduce this bug steadily:
[global]
name=iouring-sqpoll-iopoll-1
ioengine=io_uring
iodepth=128
numjobs=1
thread
rw=randread
direct=1
registerfiles=1
hipri=1
bs=4m
size=100M
runtime=120
time_based
group_reporting
randrepeat=0
[device]
directory=/home/feiman.wxg/mntpoint/ # an ext4 mount point
If we have commit cc29e1bf0d63f7 ("block: disable iopoll for split bio"),
there will no splitted bio case for polled io, but I think we still to need
to fix this list corruption, it also should maybe go to stable branchs.
To fix this corruption, if a req is inserted into tail of io_wqe->work_list,
initialize req->io_wq_work->list->next to bu NULL.
Cc: stable@vger.kernel.org
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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When remounting RO, after setting the superblock with the RO flag, the
cleaner task will start sleeping and do nothing, since the call to
btrfs_need_cleaner_sleep() keeps returning 'true'. However, when the
cleaner task goes to sleep, the list of delayed iputs may not be empty.
As long as we are in RO mode, the cleaner task will keep sleeping and
never run the delayed iputs. This means that if a filesystem unmount
is started, we get into close_ctree() with a non-empty list of delayed
iputs, and because the filesystem is in RO mode and is not in an error
state (or a transaction aborted), btrfs_error_commit_super() and
btrfs_commit_super(), which run the delayed iputs, are never called,
and later we fail the assertion that checks if the delayed iputs list
is empty:
assertion failed: list_empty(&fs_info->delayed_iputs), in fs/btrfs/disk-io.c:4049
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3153!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 1 PID: 3780621 Comm: umount Tainted: G L 5.6.0-rc2-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
RIP: 0010:assertfail.constprop.0+0x18/0x26 [btrfs]
Code: 8b 7b 58 48 85 ff 74 (...)
RSP: 0018:ffffb748c89bbdf8 EFLAGS: 00010246
RAX: 0000000000000051 RBX: ffff9608f2584000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff91998988 RDI: 00000000ffffffff
RBP: ffff9608f25870d8 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffc0cbc500
R13: ffffffff92411750 R14: 0000000000000000 R15: ffff9608f2aab250
FS: 00007fcbfaa66c80(0000) GS:ffff960936c80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc2c2dd38 CR3: 0000000235e54002 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
close_ctree+0x1a2/0x2e6 [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x93/0xc0
exit_to_usermode_loop+0xf9/0x100
do_syscall_64+0x20d/0x260
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fcbfaca6307
Code: eb 0b 00 f7 d8 64 89 (...)
RSP: 002b:00007fffc2c2ed68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000558203b559b0 RCX: 00007fcbfaca6307
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000558203b55bc0
RBP: 0000000000000000 R08: 0000000000000001 R09: 00007fffc2c2dad0
R10: 0000558203b55bf0 R11: 0000000000000246 R12: 0000558203b55bc0
R13: 00007fcbfadcc204 R14: 0000558203b55aa8 R15: 0000000000000000
Modules linked in: btrfs dm_flakey dm_log_writes (...)
---[ end trace d44d303790049ef6 ]---
So fix this by making the remount RO path run any remaining delayed iputs
after waiting for the cleaner to become inactive.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Add an assertion to close_ctree(), after destroying all the work queues,
to verify we do not have any transaction still open or committing at that
at that point. If we have any, it means something is seriously wrong and
that can cause memory leaks and use-after-free problems. This is motivated
by the previous patches that fixed bugs where we ended up leaking an open
transaction after unmounting the filesystem.
Tested-by: Fabian Vogt <fvogt@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When we are remounting a filesystem in RO mode we can race with the cleaner
task and result in leaking a transaction if the filesystem is unmounted
shortly after, before the transaction kthread had a chance to commit that
transaction. That also results in a crash during unmount, due to a
use-after-free, if hardware acceleration is not available for crc32c.
The following sequence of steps explains how the race happens.
1) The filesystem is mounted in RW mode and the cleaner task is running.
This means that currently BTRFS_FS_CLEANER_RUNNING is set at
fs_info->flags;
2) The cleaner task is currently running delayed iputs for example;
3) A filesystem RO remount operation starts;
4) The RO remount task calls btrfs_commit_super(), which commits any
currently open transaction, and it finishes;
5) At this point the cleaner task is still running and it creates a new
transaction by doing one of the following things:
* When running the delayed iput() for an inode with a 0 link count,
in which case at btrfs_evict_inode() we start a transaction through
the call to evict_refill_and_join(), use it and then release its
handle through btrfs_end_transaction();
* When deleting a dead root through btrfs_clean_one_deleted_snapshot(),
a transaction is started at btrfs_drop_snapshot() and then its handle
is released through a call to btrfs_end_transaction_throttle();
* When the remount task was still running, and before the remount task
called btrfs_delete_unused_bgs(), the cleaner task also called
btrfs_delete_unused_bgs() and it picked and removed one block group
from the list of unused block groups. Before the cleaner task started
a transaction, through btrfs_start_trans_remove_block_group() at
btrfs_delete_unused_bgs(), the remount task had already called
btrfs_commit_super();
6) So at this point the filesystem is in RO mode and we have an open
transaction that was started by the cleaner task;
7) Shortly after a filesystem unmount operation starts. At close_ctree()
we stop the transaction kthread before it had a chance to commit the
transaction, since less than 30 seconds (the default commit interval)
have elapsed since the last transaction was committed;
8) We end up calling iput() against the btree inode at close_ctree() while
there is an open transaction, and since that transaction was used to
update btrees by the cleaner, we have dirty pages in the btree inode
due to COW operations on metadata extents, and therefore writeback is
triggered for the btree inode.
So btree_write_cache_pages() is invoked to flush those dirty pages
during the final iput() on the btree inode. This results in creating a
bio and submitting it, which makes us end up at
btrfs_submit_metadata_bio();
9) At btrfs_submit_metadata_bio() we end up at the if-then-else branch
that calls btrfs_wq_submit_bio(), because check_async_write() returned
a value of 1. This value of 1 is because we did not have hardware
acceleration available for crc32c, so BTRFS_FS_CSUM_IMPL_FAST was not
set in fs_info->flags;
10) Then at btrfs_wq_submit_bio() we call btrfs_queue_work() against the
workqueue at fs_info->workers, which was already freed before by the
call to btrfs_stop_all_workers() at close_ctree(). This results in an
invalid memory access due to a use-after-free, leading to a crash.
When this happens, before the crash there are several warnings triggered,
since we have reserved metadata space in a block group, the delayed refs
reservation, etc:
------------[ cut here ]------------
WARNING: CPU: 4 PID: 1729896 at fs/btrfs/block-group.c:125 btrfs_put_block_group+0x63/0xa0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 4 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_put_block_group+0x63/0xa0 [btrfs]
Code: f0 01 00 00 48 39 c2 75 (...)
RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206
RAX: 0000000000000001 RBX: ffff947ed73e4000 RCX: ffff947ebc8b29c8
RDX: 0000000000000001 RSI: ffffffffc0b150a0 RDI: ffff947ebc8b2800
RBP: ffff947ebc8b2800 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110
R13: ffff947ed73e4160 R14: ffff947ebc8b2988 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481ad600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37e2893320 CR3: 0000000138f68001 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_free_block_groups+0x17f/0x2f0 [btrfs]
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 01 48 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c6 ]---
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-rsv.c:459 btrfs_release_global_block_rsv+0x70/0xc0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 2 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_release_global_block_rsv+0x70/0xc0 [btrfs]
Code: 48 83 bb b0 03 00 00 00 (...)
RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206
RAX: 000000000033c000 RBX: ffff947ed73e4000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffc0b0d8c1 RDI: 00000000ffffffff
RBP: ffff947ebc8b7000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110
R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481aca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561a79f76e20 CR3: 0000000138f68006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_free_block_groups+0x24c/0x2f0 [btrfs]
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 01 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c7 ]---
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-group.c:3377 btrfs_free_block_groups+0x25d/0x2f0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 5 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_free_block_groups+0x25d/0x2f0 [btrfs]
Code: ad de 49 be 22 01 00 (...)
RSP: 0018:ffffb270826bbde8 EFLAGS: 00010206
RAX: ffff947ebeae1d08 RBX: ffff947ed73e4000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff947e9d823ae8 RDI: 0000000000000246
RBP: ffff947ebeae1d08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ebeae1c00
R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481ad200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1475d98ea8 CR3: 0000000138f68005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c8 ]---
BTRFS info (device sdc): space_info 4 has 268238848 free, is not full
BTRFS info (device sdc): space_info total=268435456, used=114688, pinned=0, reserved=16384, may_use=0, readonly=65536
BTRFS info (device sdc): global_block_rsv: size 0 reserved 0
BTRFS info (device sdc): trans_block_rsv: size 0 reserved 0
BTRFS info (device sdc): chunk_block_rsv: size 0 reserved 0
BTRFS info (device sdc): delayed_block_rsv: size 0 reserved 0
BTRFS info (device sdc): delayed_refs_rsv: size 524288 reserved 0
And the crash, which only happens when we do not have crc32c hardware
acceleration, produces the following trace immediately after those
warnings:
stack segment: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 2 PID: 1749129 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_queue_work+0x36/0x190 [btrfs]
Code: 54 55 53 48 89 f3 (...)
RSP: 0018:ffffb27082443ae8 EFLAGS: 00010282
RAX: 0000000000000004 RBX: ffff94810ee9ad90 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff94810ee9ad90 RDI: ffff947ed8ee75a0
RBP: a56b6b6b6b6b6b6b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000001 R12: ffff947fa9b435a8
R13: ffff94810ee9ad90 R14: 0000000000000000 R15: ffff947e93dc0000
FS: 00007f3cfe974840(0000) GS:ffff9481ac600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1b42995a70 CR3: 0000000127638003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_wq_submit_bio+0xb3/0xd0 [btrfs]
btrfs_submit_metadata_bio+0x44/0xc0 [btrfs]
submit_one_bio+0x61/0x70 [btrfs]
btree_write_cache_pages+0x414/0x450 [btrfs]
? kobject_put+0x9a/0x1d0
? trace_hardirqs_on+0x1b/0xf0
? _raw_spin_unlock_irqrestore+0x3c/0x60
? free_debug_processing+0x1e1/0x2b0
do_writepages+0x43/0xe0
? lock_acquired+0x199/0x490
__writeback_single_inode+0x59/0x650
writeback_single_inode+0xaf/0x120
write_inode_now+0x94/0xd0
iput+0x187/0x2b0
close_ctree+0x2c6/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f3cfebabee7
Code: ff 0b 00 f7 d8 64 89 01 (...)
RSP: 002b:00007ffc9c9a05f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3cfecd1264 RCX: 00007f3cfebabee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 0000562b6b478000
RBP: 0000562b6b473a30 R08: 0000000000000000 R09: 00007f3cfec6cbe0
R10: 0000562b6b479fe0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000562b6b478000 R14: 0000562b6b473b40 R15: 0000562b6b473c60
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
---[ end trace dd74718fef1ed5cc ]---
Finally when we remove the btrfs module (rmmod btrfs), there are several
warnings about objects that were allocated from our slabs but were never
freed, consequence of the transaction that was never committed and got
leaked:
=============================================================================
BUG btrfs_delayed_ref_head (Tainted: G B W ): Objects remaining in btrfs_delayed_ref_head on __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO: Slab 0x0000000094c2ae56 objects=24 used=2 fp=0x000000002bfa2521 flags=0x17fffc000010200
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
slab_err+0xb7/0xdc
? lock_acquired+0x199/0x490
__kmem_cache_shutdown+0x1ac/0x3c0
? lock_release+0x20e/0x4c0
kmem_cache_destroy+0x55/0x120
btrfs_delayed_ref_exit+0x11/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
INFO: Object 0x0000000050cbdd61 @offset=12104
INFO: Allocated in btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] age=1894 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs]
btrfs_free_tree_block+0x128/0x360 [btrfs]
__btrfs_cow_block+0x489/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x13b/0x3e0 [btrfs]
INFO: Freed in __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] age=4292 cpu=2 pid=1729526
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x1117/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
commit_cowonly_roots+0xfb/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
sync_filesystem+0x74/0x90
generic_shutdown_super+0x22/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
INFO: Object 0x0000000086e9b0ff @offset=12776
INFO: Allocated in btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs] age=1900 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0xbb/0x480 [btrfs]
btrfs_alloc_tree_block+0x2bf/0x360 [btrfs]
alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs]
__btrfs_cow_block+0x12d/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
INFO: Freed in __btrfs_run_delayed_refs+0x1117/0x1290 [btrfs] age=3141 cpu=6 pid=1729803
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x1117/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
btrfs_write_dirty_block_groups+0x17d/0x3d0 [btrfs]
commit_cowonly_roots+0x248/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
close_ctree+0x113/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
kmem_cache_destroy btrfs_delayed_ref_head: Slab cache still has objects
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
kmem_cache_destroy+0x119/0x120
btrfs_delayed_ref_exit+0x11/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 0b (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
=============================================================================
BUG btrfs_delayed_tree_ref (Tainted: G B W ): Objects remaining in btrfs_delayed_tree_ref on __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO: Slab 0x0000000011f78dc0 objects=37 used=2 fp=0x0000000032d55d91 flags=0x17fffc000010200
CPU: 3 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
slab_err+0xb7/0xdc
? lock_acquired+0x199/0x490
__kmem_cache_shutdown+0x1ac/0x3c0
? lock_release+0x20e/0x4c0
kmem_cache_destroy+0x55/0x120
btrfs_delayed_ref_exit+0x1d/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
INFO: Object 0x000000001a340018 @offset=4408
INFO: Allocated in btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] age=1917 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs]
btrfs_free_tree_block+0x128/0x360 [btrfs]
__btrfs_cow_block+0x489/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x13b/0x3e0 [btrfs]
INFO: Freed in __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] age=4167 cpu=4 pid=1729795
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x63d/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
btrfs_commit_transaction+0x60/0xc40 [btrfs]
create_subvol+0x56a/0x990 [btrfs]
btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
__btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
btrfs_ioctl_snap_create+0x58/0x80 [btrfs]
btrfs_ioctl+0x1a92/0x36f0 [btrfs]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
INFO: Object 0x000000002b46292a @offset=13648
INFO: Allocated in btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs] age=1923 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_add_delayed_tree_ref+0x9e/0x480 [btrfs]
btrfs_alloc_tree_block+0x2bf/0x360 [btrfs]
alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs]
__btrfs_cow_block+0x12d/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
INFO: Freed in __btrfs_run_delayed_refs+0x63d/0x1290 [btrfs] age=3164 cpu=6 pid=1729803
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0x63d/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
commit_cowonly_roots+0xfb/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
close_ctree+0x113/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
kmem_cache_destroy btrfs_delayed_tree_ref: Slab cache still has objects
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
kmem_cache_destroy+0x119/0x120
btrfs_delayed_ref_exit+0x1d/0x35 [btrfs]
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
=============================================================================
BUG btrfs_delayed_extent_op (Tainted: G B W ): Objects remaining in btrfs_delayed_extent_op on __kmem_cache_shutdown()
-----------------------------------------------------------------------------
INFO: Slab 0x00000000f145ce2f objects=22 used=1 fp=0x00000000af0f92cf flags=0x17fffc000010200
CPU: 5 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
slab_err+0xb7/0xdc
? lock_acquired+0x199/0x490
__kmem_cache_shutdown+0x1ac/0x3c0
? __mutex_unlock_slowpath+0x45/0x2a0
kmem_cache_destroy+0x55/0x120
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 f5 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
INFO: Object 0x000000004cf95ea8 @offset=6264
INFO: Allocated in btrfs_alloc_tree_block+0x1e0/0x360 [btrfs] age=1931 cpu=6 pid=1729873
__slab_alloc.isra.0+0x109/0x1c0
kmem_cache_alloc+0x7bb/0x830
btrfs_alloc_tree_block+0x1e0/0x360 [btrfs]
alloc_tree_block_no_bg_flush+0x4f/0x60 [btrfs]
__btrfs_cow_block+0x12d/0x5f0 [btrfs]
btrfs_cow_block+0xf7/0x220 [btrfs]
btrfs_search_slot+0x62a/0xc40 [btrfs]
btrfs_del_orphan_item+0x65/0xd0 [btrfs]
btrfs_find_orphan_roots+0x1bf/0x200 [btrfs]
open_ctree+0x125a/0x18a0 [btrfs]
btrfs_mount_root.cold+0x13/0xed [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xe0
fc_mount+0xe/0x40
vfs_kern_mount.part.0+0x71/0x90
btrfs_mount+0x13b/0x3e0 [btrfs]
INFO: Freed in __btrfs_run_delayed_refs+0xabd/0x1290 [btrfs] age=3173 cpu=6 pid=1729803
kmem_cache_free+0x34c/0x3c0
__btrfs_run_delayed_refs+0xabd/0x1290 [btrfs]
btrfs_run_delayed_refs+0x81/0x210 [btrfs]
commit_cowonly_roots+0xfb/0x300 [btrfs]
btrfs_commit_transaction+0x367/0xc40 [btrfs]
close_ctree+0x113/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
kmem_cache_destroy btrfs_delayed_extent_op: Slab cache still has objects
CPU: 3 PID: 1729921 Comm: rmmod Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x8d/0xb5
kmem_cache_destroy+0x119/0x120
exit_btrfs_fs+0xa/0x59 [btrfs]
__x64_sys_delete_module+0x194/0x260
? fpregs_assert_state_consistent+0x1e/0x40
? exit_to_user_mode_prepare+0x55/0x1c0
? trace_hardirqs_on+0x1b/0xf0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f693e305897
Code: 73 01 c3 48 8b 0d f9 (...)
RSP: 002b:00007ffcf73eb508 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 0000559df504f760 RCX: 00007f693e305897
RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559df504f7c8
RBP: 00007ffcf73eb568 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f693e378ac0 R11: 0000000000000206 R12: 00007ffcf73eb740
R13: 00007ffcf73ec5a6 R14: 0000559df504f2a0 R15: 0000559df504f760
BTRFS: state leak: start 30408704 end 30425087 state 1 in tree 1 refs 1
So fix this by making the remount path to wait for the cleaner task before
calling btrfs_commit_super(). The remount path now waits for the bit
BTRFS_FS_CLEANER_RUNNING to be cleared from fs_info->flags before calling
btrfs_commit_super() and this ensures the cleaner can not start a
transaction after that, because it sleeps when the filesystem is in RO
mode and we have already flagged the filesystem as RO before waiting for
BTRFS_FS_CLEANER_RUNNING to be cleared.
This also introduces a new flag BTRFS_FS_STATE_RO to be used for
fs_info->fs_state when the filesystem is in RO mode. This is because we
were doing the RO check using the flags of the superblock and setting the
RO mode simply by ORing into the superblock's flags - those operations are
not atomic and could result in the cleaner not seeing the update from the
remount task after it clears BTRFS_FS_CLEANER_RUNNING.
Tested-by: Fabian Vogt <fvogt@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When we delete a root (subvolume or snapshot), at the very end of the
operation, we attempt to remove the root's orphan item from the root tree,
at btrfs_drop_snapshot(), by calling btrfs_del_orphan_item(). We ignore any
error from btrfs_del_orphan_item() since it is not a serious problem and
the next time the filesystem is mounted we remove such stray orphan items
at btrfs_find_orphan_roots().
However if the filesystem is mounted RO and we have stray orphan items for
any previously deleted root, we can end up leaking a transaction and other
data structures when unmounting the filesystem, as well as crashing if we
do not have hardware acceleration for crc32c available.
The steps that lead to the transaction leak are the following:
1) The filesystem is mounted in RW mode;
2) A subvolume is deleted;
3) When the cleaner kthread runs btrfs_drop_snapshot() to delete the root,
it gets a failure at btrfs_del_orphan_item(), which is ignored, due to
an ENOMEM when allocating a path for example. So the orphan item for
the root remains in the root tree;
4) The filesystem is unmounted;
5) The filesystem is mounted RO (-o ro). During the mount path we call
btrfs_find_orphan_roots(), which iterates the root tree searching for
orphan items. It finds the orphan item for our deleted root, and since
it can not find the root, it starts a transaction to delete the orphan
item (by calling btrfs_del_orphan_item());
6) The RO mount completes;
7) Before the transaction kthread commits the transaction created for
deleting the orphan item (i.e. less than 30 seconds elapsed since the
mount, the default commit interval), a filesystem unmount operation is
started;
8) At close_ctree(), we stop the transaction kthread, but we still have a
transaction open with at least one dirty extent buffer, a leaf for the
tree root which was COWed when deleting the orphan item;
9) We then proceed to destroy the work queues, free the roots and block
groups, etc. After that we drop the last reference on the btree inode by
calling iput() on it. Since there are dirty pages for the btree inode,
corresponding to the COWed extent buffer, btree_write_cache_pages() is
invoked to flush those dirty pages. This results in creating a bio and
submitting it, which makes us end up at btrfs_submit_metadata_bio();
10) At btrfs_submit_metadata_bio() we end up at the if-then-else branch
that calls btrfs_wq_submit_bio(), because check_async_write() returned
a value of 1. This value of 1 is because we did not have hardware
acceleration available for crc32c, so BTRFS_FS_CSUM_IMPL_FAST was not
set in fs_info->flags;
11) Then at btrfs_wq_submit_bio() we call btrfs_queue_work() against the
workqueue at fs_info->workers, which was already freed before by the
call to btrfs_stop_all_workers() at close_ctree(). This results in an
invalid memory access due to a use-after-free, leading to a crash.
When this happens, before the crash there are several warnings triggered,
since we have reserved metadata space in a block group, the delayed refs
reservation, etc:
------------[ cut here ]------------
WARNING: CPU: 4 PID: 1729896 at fs/btrfs/block-group.c:125 btrfs_put_block_group+0x63/0xa0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 4 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_put_block_group+0x63/0xa0 [btrfs]
Code: f0 01 00 00 48 39 c2 75 (...)
RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206
RAX: 0000000000000001 RBX: ffff947ed73e4000 RCX: ffff947ebc8b29c8
RDX: 0000000000000001 RSI: ffffffffc0b150a0 RDI: ffff947ebc8b2800
RBP: ffff947ebc8b2800 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110
R13: ffff947ed73e4160 R14: ffff947ebc8b2988 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481ad600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37e2893320 CR3: 0000000138f68001 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_free_block_groups+0x17f/0x2f0 [btrfs]
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 01 48 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c6 ]---
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-rsv.c:459 btrfs_release_global_block_rsv+0x70/0xc0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 2 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_release_global_block_rsv+0x70/0xc0 [btrfs]
Code: 48 83 bb b0 03 00 00 00 (...)
RSP: 0018:ffffb270826bbdd8 EFLAGS: 00010206
RAX: 000000000033c000 RBX: ffff947ed73e4000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffc0b0d8c1 RDI: 00000000ffffffff
RBP: ffff947ebc8b7000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ed73e4110
R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481aca00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561a79f76e20 CR3: 0000000138f68006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_free_block_groups+0x24c/0x2f0 [btrfs]
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 01 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c7 ]---
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1729896 at fs/btrfs/block-group.c:3377 btrfs_free_block_groups+0x25d/0x2f0 [btrfs]
Modules linked in: btrfs dm_snapshot dm_thin_pool (...)
CPU: 5 PID: 1729896 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_free_block_groups+0x25d/0x2f0 [btrfs]
Code: ad de 49 be 22 01 00 (...)
RSP: 0018:ffffb270826bbde8 EFLAGS: 00010206
RAX: ffff947ebeae1d08 RBX: ffff947ed73e4000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff947e9d823ae8 RDI: 0000000000000246
RBP: ffff947ebeae1d08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff947ebeae1c00
R13: ffff947ed73e5278 R14: dead000000000122 R15: dead000000000100
FS: 00007f15edfea840(0000) GS:ffff9481ad200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1475d98ea8 CR3: 0000000138f68005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
close_ctree+0x2ba/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f15ee221ee7
Code: ff 0b 00 f7 d8 64 89 (...)
RSP: 002b:00007ffe9470f0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f15ee347264 RCX: 00007f15ee221ee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 000056169701d000
RBP: 0000561697018a30 R08: 0000000000000000 R09: 00007f15ee2e2be0
R10: 000056169701efe0 R11: 0000000000000246 R12: 0000000000000000
R13: 000056169701d000 R14: 0000561697018b40 R15: 0000561697018c60
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last enabled at (0): [<ffffffff8bcae560>] copy_process+0x8a0/0x1d70
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace dd74718fef1ed5c8 ]---
BTRFS info (device sdc): space_info 4 has 268238848 free, is not full
BTRFS info (device sdc): space_info total=268435456, used=114688, pinned=0, reserved=16384, may_use=0, readonly=65536
BTRFS info (device sdc): global_block_rsv: size 0 reserved 0
BTRFS info (device sdc): trans_block_rsv: size 0 reserved 0
BTRFS info (device sdc): chunk_block_rsv: size 0 reserved 0
BTRFS info (device sdc): delayed_block_rsv: size 0 reserved 0
BTRFS info (device sdc): delayed_refs_rsv: size 524288 reserved 0
And the crash, which only happens when we do not have crc32c hardware
acceleration, produces the following trace immediately after those
warnings:
stack segment: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 2 PID: 1749129 Comm: umount Tainted: G B W 5.10.0-rc4-btrfs-next-73 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_queue_work+0x36/0x190 [btrfs]
Code: 54 55 53 48 89 f3 (...)
RSP: 0018:ffffb27082443ae8 EFLAGS: 00010282
RAX: 0000000000000004 RBX: ffff94810ee9ad90 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffff94810ee9ad90 RDI: ffff947ed8ee75a0
RBP: a56b6b6b6b6b6b6b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000001 R12: ffff947fa9b435a8
R13: ffff94810ee9ad90 R14: 0000000000000000 R15: ffff947e93dc0000
FS: 00007f3cfe974840(0000) GS:ffff9481ac600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1b42995a70 CR3: 0000000127638003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_wq_submit_bio+0xb3/0xd0 [btrfs]
btrfs_submit_metadata_bio+0x44/0xc0 [btrfs]
submit_one_bio+0x61/0x70 [btrfs]
btree_write_cache_pages+0x414/0x450 [btrfs]
? kobject_put+0x9a/0x1d0
? trace_hardirqs_on+0x1b/0xf0
? _raw_spin_unlock_irqrestore+0x3c/0x60
? free_debug_processing+0x1e1/0x2b0
do_writepages+0x43/0xe0
? lock_acquired+0x199/0x490
__writeback_single_inode+0x59/0x650
writeback_single_inode+0xaf/0x120
write_inode_now+0x94/0xd0
iput+0x187/0x2b0
close_ctree+0x2c6/0x2fa [btrfs]
generic_shutdown_super+0x6c/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x31/0x70
cleanup_mnt+0x100/0x160
task_work_run+0x68/0xb0
exit_to_user_mode_prepare+0x1bb/0x1c0
syscall_exit_to_user_mode+0x4b/0x260
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f3cfebabee7
Code: ff 0b 00 f7 d8 64 89 01 (...)
RSP: 002b:00007ffc9c9a05f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3cfecd1264 RCX: 00007f3cfebabee7
RDX: ffffffffffffff78 RSI: 0000000000000000 RDI: 0000562b6b478000
RBP: 0000562b6b473a30 R08: 0000000000000000 R09: 00007f3cfec6cbe0
R10: 0000562b6b479fe0 R11: 0000000000000246 R12: 0000000000000000 |
