syzbot reported a deadlock in mark_as_free_ex. [1]
Reset the order of mft and used locks to avoid this issue.
[1]
WARNING: possible circular locking dependency detected
6.13.0-rc2-syzkaller-00036-g231825b2e1ff #0 Not tainted
------------------------------------------------------
syz-executor149/6544 is trying to acquire lock:
ffff88807e17a270 (&wnd->rw_lock){++++}-{4:4}, at: mark_as_free_ex+0x3e/0x390 fs/ntfs3/fsntfs.c:2484
but task is already holding lock:
ffff8880705e43c8 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_truncate fs/ntfs3/file.c:505 [inline]
ffff8880705e43c8 (&ni->file.run_lock#2){++++}-{4:4}, at: ntfs_setattr+0x6d3/0xb80 fs/ntfs3/file.c:824
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&ni->file.run_lock#2){++++}-{4:4}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
run_unpack_ex+0x55e/0x9e0 fs/ntfs3/run.c:1119
ntfs_read_mft fs/ntfs3/inode.c:401 [inline]
ntfs_iget5+0x1f9a/0x37b0 fs/ntfs3/inode.c:537
ntfs_dir_emit fs/ntfs3/dir.c:335 [inline]
ntfs_read_hdr+0x700/0xb80 fs/ntfs3/dir.c:383
ntfs_readdir+0x91f/0xf00 fs/ntfs3/dir.c:494
iterate_dir+0x571/0x800 fs/readdir.c:108
__do_sys_getdents64 fs/readdir.c:403 [inline]
__se_sys_getdents64+0x1e2/0x4b0 fs/readdir.c:389
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&wnd->rw_lock){++++}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
mark_as_free_ex+0x3e/0x390 fs/ntfs3/fsntfs.c:2484
run_deallocate_ex+0x244/0x5f0 fs/ntfs3/attrib.c:122
attr_set_size+0x168d/0x4300 fs/ntfs3/attrib.c:753
ntfs_truncate fs/ntfs3/file.c:506 [inline]
ntfs_setattr+0x7a4/0xb80 fs/ntfs3/file.c:824
notify_change+0xbca/0xe90 fs/attr.c:552
do_truncate+0x220/0x310 fs/open.c:65
handle_truncate fs/namei.c:3449 [inline]
do_open fs/namei.c:3832 [inline]
path_openat+0x2e1e/0x3590 fs/namei.c:3987
do_filp_open+0x27f/0x4e0 fs/namei.c:4014
do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_open fs/open.c:1425 [inline]
__se_sys_open fs/open.c:1421 [inline]
__x64_sys_open+0x225/0x270 fs/open.c:1421
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ni->file.run_lock#2);
lock(&wnd->rw_lock);
lock(&ni->file.run_lock#2);
lock(&wnd->rw_lock);
*** DEADLOCK ***
Fixes: 5fc982fe7eca ("fs/ntfs3: Fix case when unmarked clusters intersect with zone")
Reported-by: syzbot+8df514c431bd240c5644@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=8df514c431bd240c5644
Tested-by: syzbot+8df514c431bd240c5644@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Lizhi Xu <lizhi.xu@xxxxxxxxxxxxx>
---
fs/ntfs3/run.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/fs/ntfs3/run.c b/fs/ntfs3/run.c
index 6e86d66197ef..fdac1f941379 100644
--- a/fs/ntfs3/run.c
+++ b/fs/ntfs3/run.c
@@ -1096,9 +1096,17 @@ int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
/* Looks like volume is corrupted. */
ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
-
- if (!down_write_trylock(&wnd->rw_lock))
+ struct rw_semaphore *lock =
+ is_mounted(sbi) ? &sbi->mft.ni->file.run_lock :
+ NULL;
+ if (zone && lock)
+ down_read(lock);
+
+ if (!down_write_trylock(&wnd->rw_lock)) {
+ if (zone && lock)
+ up_read(lock);
continue;
+ }
if (zone) {
/*
@@ -1112,16 +1120,12 @@ int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
err = wnd_set_used_safe(wnd, lcn, len, &done);
if (zone) {
/* Restore zone. Lock mft run. */
- struct rw_semaphore *lock =
- is_mounted(sbi) ? &sbi->mft.ni->file.run_lock :
- NULL;
- if (lock)
- down_read(lock);
ntfs_refresh_zone(sbi);
- if (lock)
- up_read(lock);
}
up_write(&wnd->rw_lock);
+ if (zone && lock)
+ up_read(lock);
+
if (err)
return err;
}
--
2.43.0
