====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.344/6315 is trying to acquire lock: ffff0000cbc50410 (sb_writers#3){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:977 [inline] ffff0000cbc50410 (sb_writers#3){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1189 [inline] ffff0000cbc50410 (sb_writers#3){.+.+}-{0:0}, at: ovl_copy_up_flags+0x980/0x28a4 fs/overlayfs/copy_up.c:1243 but task is already holding lock: ffff0000f25fdcd8 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:705 [inline] ffff0000f25fdcd8 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x58/0x264 fs/overlayfs/util.c:735 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ovl_i_lock_key[depth]){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x160/0xef8 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_copy_up_start+0x58/0x264 fs/overlayfs/util.c:735 ovl_copy_up_one fs/overlayfs/copy_up.c:1182 [inline] ovl_copy_up_flags+0x768/0x28a4 fs/overlayfs/copy_up.c:1243 ovl_copy_up+0x24/0x34 fs/overlayfs/copy_up.c:1282 ovl_link+0x8c/0x26c fs/overlayfs/dir.c:774 vfs_link+0x40c/0x580 fs/namei.c:5774 filename_linkat+0x224/0x478 fs/namei.c:5842 __do_sys_linkat fs/namei.c:5868 [inline] __se_sys_linkat fs/namei.c:5863 [inline] __arm64_sys_linkat+0xe8/0x118 fs/namei.c:5863 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 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+0x194/0x3580 fs/ext4/move_extent.c:589 __ext4_ioctl fs/ext4/ioctl.c:1657 [inline] ext4_ioctl+0x2a14/0x4234 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+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 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+0x1780/0x2f44 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x368 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 include/linux/fs/super.h:125 [inline] ovl_start_write+0xf0/0x324 fs/overlayfs/util.c:32 ovl_do_copy_up fs/overlayfs/copy_up.c:977 [inline] ovl_copy_up_one fs/overlayfs/copy_up.c:1189 [inline] ovl_copy_up_flags+0x980/0x28a4 fs/overlayfs/copy_up.c:1243 ovl_copy_up+0x24/0x34 fs/overlayfs/copy_up.c:1282 ovl_xattr_set+0x284/0x47c fs/overlayfs/xattrs.c:54 ovl_other_xattr_set+0x50/0x68 fs/overlayfs/xattrs.c:224 __vfs_setxattr+0x130/0x17c fs/xattr.c:218 __vfs_setxattr_noperm+0x120/0x5c4 fs/xattr.c:252 __vfs_setxattr_locked+0x114/0x248 fs/xattr.c:313 vfs_setxattr+0x150/0x2e0 fs/xattr.c:339 do_setxattr+0xf8/0x190 fs/xattr.c:654 filename_setxattr+0x134/0x1f8 fs/xattr.c:682 path_setxattrat+0x200/0x2a8 fs/xattr.c:726 __do_sys_setxattr fs/xattr.c:760 [inline] __se_sys_setxattr fs/xattr.c:756 [inline] __arm64_sys_setxattr+0xc0/0xdc fs/xattr.c:756 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 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] --> &ovl_i_lock_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_lock_key[depth]); lock(&ovl_i_mutex_key[depth]); lock(&ovl_i_lock_key[depth]); rlock(sb_writers#3); *** DEADLOCK *** 3 locks held by syz.5.344/6315: #0: ffff0000f5150410 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:493 #1: ffff0000f25fd960 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff0000f25fd960 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: vfs_setxattr+0x130/0x2e0 fs/xattr.c:338 #2: ffff0000f25fdcd8 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:705 [inline] #2: ffff0000f25fdcd8 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x58/0x264 fs/overlayfs/util.c:735 stack backtrace: CPU: 1 UID: 0 PID: 6315 Comm: syz.5.344 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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+0x1780/0x2f44 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x368 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 include/linux/fs/super.h:125 [inline] ovl_start_write+0xf0/0x324 fs/overlayfs/util.c:32 ovl_do_copy_up fs/overlayfs/copy_up.c:977 [inline] ovl_copy_up_one fs/overlayfs/copy_up.c:1189 [inline] ovl_copy_up_flags+0x980/0x28a4 fs/overlayfs/copy_up.c:1243 ovl_copy_up+0x24/0x34 fs/overlayfs/copy_up.c:1282 ovl_xattr_set+0x284/0x47c fs/overlayfs/xattrs.c:54 ovl_other_xattr_set+0x50/0x68 fs/overlayfs/xattrs.c:224 __vfs_setxattr+0x130/0x17c fs/xattr.c:218 __vfs_setxattr_noperm+0x120/0x5c4 fs/xattr.c:252 __vfs_setxattr_locked+0x114/0x248 fs/xattr.c:313 vfs_setxattr+0x150/0x2e0 fs/xattr.c:339 do_setxattr+0xf8/0x190 fs/xattr.c:654 filename_setxattr+0x134/0x1f8 fs/xattr.c:682 path_setxattrat+0x200/0x2a8 fs/xattr.c:726 __do_sys_setxattr fs/xattr.c:760 [inline] __se_sys_setxattr fs/xattr.c:756 [inline] __arm64_sys_setxattr+0xc0/0xdc fs/xattr.c:756 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 EXT4-fs error (device loop5): ext4_find_dest_de:2050: inode #12: block 7: comm syz.5.344: bad entry in directory: rec_len is too small for name_len - offset=16, inode=14, rec_len=40, size=56 fake=0 EXT4-fs (loop5): Remounting filesystem read-only