loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/4911 is trying to acquire lock:
ffff0000d8394410 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:493
but task is already holding lock:
ffff0000f059a028 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:705 [inline]
ffff0000f059a028 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_nlink_start+0xc8/0x350 fs/overlayfs/util.c:1173
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ovl_i_lock_key[depth]){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x164/0xed0 kernel/locking/mutex.c:820
mutex_lock_interruptible_nested+0x24/0x30 kernel/locking/mutex.c:898
ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:705 [inline]
ovl_nlink_start+0xc8/0x350 fs/overlayfs/util.c:1173
ovl_rename_start fs/overlayfs/dir.c:1189 [inline]
ovl_rename+0x3b0/0xf80 fs/overlayfs/dir.c:1363
vfs_rename+0xa78/0xd48 fs/namei.c:6064
filename_renameat2+0x660/0x72c fs/namei.c:6182
__do_sys_renameat2 fs/namei.c:6211 [inline]
__se_sys_renameat2 fs/namei.c:6206 [inline]
__arm64_sys_renameat2+0xec/0x11c fs/namei.c:6206
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
-> #2 (&ovl_i_mutex_key[depth]/4){+.+.}-{4:4}:
down_write_nested+0x58/0xcc kernel/locking/rwsem.c:1751
inode_lock_nested include/linux/fs.h:1074 [inline]
lock_two_nondirectories+0xe8/0x148 fs/inode.c:1256
vfs_rename+0x600/0xd48 fs/namei.c:6027
filename_renameat2+0x660/0x72c fs/namei.c:6182
__do_sys_renameat2 fs/namei.c:6211 [inline]
__se_sys_renameat2 fs/namei.c:6206 [inline]
__arm64_sys_renameat2+0xec/0x11c fs/namei.c:6206
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
-> #1 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}:
down_write+0x50/0xc0 kernel/locking/rwsem.c:1625
inode_lock include/linux/fs.h:1029 [inline]
lock_two_nondirectories+0xc4/0x148 fs/inode.c:1254
ext4_move_extents+0x194/0x3324 fs/ext4/move_extent.c:589
__ext4_ioctl fs/ext4/ioctl.c:1657 [inline]
ext4_ioctl+0x2a10/0x4280 fs/ext4/ioctl.c:1922
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:583
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
-> #0 (sb_writers#3){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x17c0/0x2ebc kernel/locking/lockdep.c:5237
lock_acquire+0x140/0x364 kernel/locking/lockdep.c:5868
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x5c/0x294 include/linux/fs/super.h:125
mnt_want_write+0x44/0x9c fs/namespace.c:493
ovl_want_write fs/overlayfs/util.c:38 [inline]
ovl_nlink_start+0x154/0x350 fs/overlayfs/util.c:1177
ovl_rename_start fs/overlayfs/dir.c:1189 [inline]
ovl_rename+0x3b0/0xf80 fs/overlayfs/dir.c:1363
vfs_rename+0xa78/0xd48 fs/namei.c:6064
filename_renameat2+0x660/0x72c fs/namei.c:6182
__do_sys_renameat2 fs/namei.c:6211 [inline]
__se_sys_renameat2 fs/namei.c:6206 [inline]
__arm64_sys_renameat2+0xec/0x11c fs/namei.c:6206
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
other info that might help us debug this:
Chain exists of:
sb_writers#3 --> &ovl_i_mutex_key[depth]/4 --> &ovl_i_lock_key[depth]
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ovl_i_lock_key[depth]);
lock(&ovl_i_mutex_key[depth]/4);
lock(&ovl_i_lock_key[depth]);
rlock(sb_writers#3);
*** DEADLOCK ***
5 locks held by syz.0.17/4911:
#0: ffff0000ce09c410 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:493
#1: ffff0000f059a7a8 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#1: ffff0000f059a7a8 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3787 [inline]
#1: ffff0000f059a7a8 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: __start_renaming+0x144/0x344 fs/namei.c:3880
#2: ffff0000f0599cb8 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
#2: ffff0000f0599cb8 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: lock_two_nondirectories+0xc4/0x148 fs/inode.c:1254
#3: ffff0000f059a230 (&ovl_i_mutex_key[depth]/4){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#3: ffff0000f059a230 (&ovl_i_mutex_key[depth]/4){+.+.}-{4:4}, at: lock_two_nondirectories+0xe8/0x148 fs/inode.c:1256
#4: ffff0000f059a028 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:705 [inline]
#4: ffff0000f059a028 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_nlink_start+0xc8/0x350 fs/overlayfs/util.c:1173
stack backtrace:
CPU: 0 UID: 0 PID: 4911 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
__dump_stack+0x30/0x40 lib/dump_stack.c:94
dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
dump_stack+0x1c/0x28 lib/dump_stack.c:129
print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2043
check_noncircular+0x158/0x174 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x17c0/0x2ebc kernel/locking/lockdep.c:5237
lock_acquire+0x140/0x364 kernel/locking/lockdep.c:5868
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x5c/0x294 include/linux/fs/super.h:125
mnt_want_write+0x44/0x9c fs/namespace.c:493
ovl_want_write fs/overlayfs/util.c:38 [inline]
ovl_nlink_start+0x154/0x350 fs/overlayfs/util.c:1177
ovl_rename_start fs/overlayfs/dir.c:1189 [inline]
ovl_rename+0x3b0/0xf80 fs/overlayfs/dir.c:1363
vfs_rename+0xa78/0xd48 fs/namei.c:6064
filename_renameat2+0x660/0x72c fs/namei.c:6182
__do_sys_renameat2 fs/namei.c:6211 [inline]
__se_sys_renameat2 fs/namei.c:6206 [inline]
__arm64_sys_renameat2+0xec/0x11c fs/namei.c:6206
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594