====================================================== WARNING: possible circular locking dependency detected 5.16.0-rc4-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor372/4062 is trying to acquire lock: ffffffff8ac98640 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:227 [inline] ffffffff8ac98640 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slab.h:492 [inline] ffffffff8ac98640 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3148 [inline] ffffffff8ac98640 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc mm/slub.c:3242 [inline] ffffffff8ac98640 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc+0x3e/0x3a0 mm/slub.c:3247 but task is already holding lock: ffff88807c7b6850 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: i_mmap_lock_read include/linux/fs.h:513 [inline] ffff88807c7b6850 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: split_huge_page_to_list+0x34a/0x2990 mm/huge_memory.c:2657 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&mapping->i_mmap_rwsem){++++}-{3:3}: down_write+0x90/0x150 kernel/locking/rwsem.c:1523 i_mmap_lock_write include/linux/fs.h:498 [inline] dma_resv_lockdep+0x2cd/0x44d drivers/dma-buf/dma-resv.c:691 do_one_initcall+0xbe/0x440 init/main.c:1297 do_initcall_level init/main.c:1370 [inline] do_initcalls init/main.c:1386 [inline] do_basic_setup init/main.c:1405 [inline] kernel_init_freeable+0x5ab/0x605 init/main.c:1610 kernel_init+0x14/0x130 init/main.c:1499 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2985/0x5410 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __fs_reclaim_acquire mm/page_alloc.c:4535 [inline] fs_reclaim_acquire+0x115/0x160 mm/page_alloc.c:4549 might_alloc include/linux/sched/mm.h:227 [inline] slab_pre_alloc_hook mm/slab.h:492 [inline] slab_alloc_node mm/slub.c:3148 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x3e/0x3a0 mm/slub.c:3247 xas_split_alloc+0x108/0x480 lib/xarray.c:1017 split_huge_page_to_list+0x5a6/0x2990 mm/huge_memory.c:2683 split_huge_page include/linux/huge_mm.h:192 [inline] truncate_inode_partial_folio+0x49c/0x710 mm/truncate.c:275 shmem_undo_range+0x551/0xf70 mm/shmem.c:954 shmem_truncate_range mm/shmem.c:1032 [inline] shmem_fallocate+0x8cd/0xcd0 mm/shmem.c:2652 vfs_fallocate+0x2a5/0xb90 fs/open.c:307 ksys_fallocate fs/open.c:330 [inline] __do_sys_fallocate fs/open.c:338 [inline] __se_sys_fallocate fs/open.c:336 [inline] __x64_sys_fallocate+0xb0/0x100 fs/open.c:336 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mapping->i_mmap_rwsem); lock(fs_reclaim); lock(&mapping->i_mmap_rwsem); lock(fs_reclaim); *** DEADLOCK *** 3 locks held by syz-executor372/4062: #0: ffff88807de5a460 (sb_writers#3){.+.+}-{0:0}, at: ksys_fallocate fs/open.c:330 [inline] #0: ffff88807de5a460 (sb_writers#3){.+.+}-{0:0}, at: __do_sys_fallocate fs/open.c:338 [inline] #0: ffff88807de5a460 (sb_writers#3){.+.+}-{0:0}, at: __se_sys_fallocate fs/open.c:336 [inline] #0: ffff88807de5a460 (sb_writers#3){.+.+}-{0:0}, at: __x64_sys_fallocate+0xb0/0x100 fs/open.c:336 #1: ffff88807c7b65f8 (&sb->s_type->i_mutex_key#8){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:783 [inline] #1: ffff88807c7b65f8 (&sb->s_type->i_mutex_key#8){+.+.}-{3:3}, at: shmem_fallocate+0x135/0xcd0 mm/shmem.c:2628 #2: ffff88807c7b6850 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: i_mmap_lock_read include/linux/fs.h:513 [inline] #2: ffff88807c7b6850 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: split_huge_page_to_list+0x34a/0x2990 mm/huge_memory.c:2657 stack backtrace: CPU: 1 PID: 4062 Comm: syz-executor372 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2143 check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2985/0x5410 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __fs_reclaim_acquire mm/page_alloc.c:4535 [inline] fs_reclaim_acquire+0x115/0x160 mm/page_alloc.c:4549 might_alloc include/linux/sched/mm.h:227 [inline] slab_pre_alloc_hook mm/slab.h:492 [inline] slab_alloc_node mm/slub.c:3148 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x3e/0x3a0 mm/slub.c:3247 xas_split_alloc+0x108/0x480 lib/xarray.c:1017 split_huge_page_to_list+0x5a6/0x2990 mm/huge_memory.c:2683 split_huge_page include/linux/huge_mm.h:192 [inline] truncate_inode_partial_folio+0x49c/0x710 mm/truncate.c:275 shmem_undo_range+0x551/0xf70 mm/shmem.c:954 shmem_truncate_range mm/shmem.c:1032 [inline] shmem_fallocate+0x8cd/0xcd0 mm/shmem.c:2652 vfs_fallocate+0x2a5/0xb90 fs/open.c:307 ksys_fallocate fs/open.c:330 [inline] __do_sys_fallocate fs/open.c:338 [inline] __se_sys_fallocate fs/open.c:336 [inline] __x64_sys_fallocate+0xb0/0x100 fs/open.c:336 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f08c6fe4809 Code: 28 c3 e8 5a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd752649e8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f08c6fe4809