WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.4/6790 is trying to acquire lock: ffff80008fb56c80 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline] ffff80008fb56c80 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4904 [inline] ffff80008fb56c80 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:5239 [inline] ffff80008fb56c80 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_cache_noprof+0x58/0x698 mm/slub.c:5771 but task is already holding lock: ffff0000f77f5b18 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_ilock+0x1d8/0x3d0 fs/xfs/xfs_inode.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&xfs_nondir_ilock_class){++++}-{4:4}: down_write_nested+0x58/0xcc kernel/locking/rwsem.c:1706 xfs_ilock+0x1d8/0x3d0 fs/xfs/xfs_inode.c:165 xfs_reclaim_inode fs/xfs/xfs_icache.c:1035 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1727 [inline] xfs_icwalk_ag+0xe4c/0x16a4 fs/xfs/xfs_icache.c:1809 xfs_icwalk fs/xfs/xfs_icache.c:1857 [inline] xfs_reclaim_inodes_nr+0x1b4/0x268 fs/xfs/xfs_icache.c:1101 xfs_fs_free_cached_objects+0x68/0x7c fs/xfs/xfs_super.c:1282 super_cache_scan+0x2f0/0x380 fs/super.c:228 do_shrink_slab+0x638/0x11b0 mm/shrinker.c:437 shrink_slab+0xc68/0xfb8 mm/shrinker.c:664 shrink_node_memcgs mm/vmscan.c:6022 [inline] shrink_node+0xe18/0x20bc mm/vmscan.c:6061 kswapd_shrink_node mm/vmscan.c:6901 [inline] balance_pgdat+0xb60/0x13b8 mm/vmscan.c:7084 kswapd+0x6d0/0xe64 mm/vmscan.c:7354 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 -> #0 (fs_reclaim){+.+.}-{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+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4301 [inline] fs_reclaim_acquire+0x8c/0x118 mm/page_alloc.c:4315 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4904 [inline] slab_alloc_node mm/slub.c:5239 [inline] __kmalloc_cache_noprof+0x58/0x698 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] iomap_fill_dirty_folios+0xf0/0x218 fs/iomap/buffered-io.c:1557 xfs_buffered_write_iomap_begin+0x8b4/0x1668 fs/xfs/xfs_iomap.c:1857 iomap_iter+0x528/0xefc fs/iomap/iter.c:110 iomap_zero_range+0x17c/0x8ec fs/iomap/buffered-io.c:1590 xfs_zero_range+0x98/0xfc fs/xfs/xfs_iomap.c:2289 xfs_reflink_zero_posteof+0x110/0x2f0 fs/xfs/xfs_reflink.c:1619 xfs_reflink_remap_prep+0x314/0x5e4 fs/xfs/xfs_reflink.c:1699 xfs_file_remap_range+0x1f4/0x758 fs/xfs/xfs_file.c:1518 vfs_clone_file_range+0x62c/0xb68 fs/remap_range.c:403 ioctl_file_clone fs/ioctl.c:239 [inline] ioctl_file_clone_range fs/ioctl.c:257 [inline] do_vfs_ioctl+0xb84/0x1834 fs/ioctl.c:544 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0xe4/0x1c4 fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xfs_nondir_ilock_class); lock(fs_reclaim); lock(&xfs_nondir_ilock_class); lock(fs_reclaim); *** DEADLOCK *** 4 locks held by syz.3.4/6790: #0: ffff0000dceca420 (sb_writers#13){.+.+}-{0:0}, at: ioctl_file_clone fs/ioctl.c:239 [inline] #0: ffff0000dceca420 (sb_writers#13){.+.+}-{0:0}, at: ioctl_file_clone_range fs/ioctl.c:257 [inline] #0: ffff0000dceca420 (sb_writers#13){.+.+}-{0:0}, at: do_vfs_ioctl+0xb84/0x1834 fs/ioctl.c:544 #1: ffff0000f77f5d30 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff0000f77f5d30 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: xfs_iolock_two_inodes_and_break_layout fs/xfs/xfs_inode.c:2716 [inline] #1: ffff0000f77f5d30 (&sb->s_type->i_mutex_key#27){+.+.}-{4:4}, at: xfs_ilock2_io_mmap+0x1a4/0x64c fs/xfs/xfs_inode.c:2792 #2: ffff0000f77f5ed0 (mapping.invalidate_lock#3){++++}-{4:4}, at: filemap_invalidate_lock_two+0x3c/0x84 mm/filemap.c:1032 #3: ffff0000f77f5b18 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_ilock+0x1d8/0x3d0 fs/xfs/xfs_inode.c:165 stack backtrace: CPU: 0 UID: 0 PID: 6790 Comm: syz.3.4 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 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+0x324/0x32c kernel/locking/lockdep.c:2043 check_noncircular+0x154/0x174 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+0x1774/0x30a4 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4301 [inline] fs_reclaim_acquire+0x8c/0x118 mm/page_alloc.c:4315 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4904 [inline] slab_alloc_node mm/slub.c:5239 [inline] __kmalloc_cache_noprof+0x58/0x698 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] iomap_fill_dirty_folios+0xf0/0x218 fs/iomap/buffered-io.c:1557 xfs_buffered_write_iomap_begin+0x8b4/0x1668 fs/xfs/xfs_iomap.c:1857 iomap_iter+0x528/0xefc fs/iomap/iter.c:110 iomap_zero_range+0x17c/0x8ec fs/iomap/buffered-io.c:1590 xfs_zero_range+0x98/0xfc fs/xfs/xfs_iomap.c:2289 xfs_reflink_zero_posteof+0x110/0x2f0 fs/xfs/xfs_reflink.c:1619 xfs_reflink_remap_prep+0x314/0x5e4 fs/xfs/xfs_reflink.c:1699 xfs_file_remap_range+0x1f4/0x758 fs/xfs/xfs_file.c:1518 vfs_clone_file_range+0x62c/0xb68 fs/remap_range.c:403 ioctl_file_clone fs/ioctl.c:239 [inline] ioctl_file_clone_range fs/ioctl.c:257 [inline] do_vfs_ioctl+0xb84/0x1834 fs/ioctl.c:544 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0xe4/0x1c4 fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596