loop0: detected capacity change from 0 to 1024 ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.0.0/5354 is trying to acquire lock: ffff8880530a1548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 but task is already holding lock: ffff8880530a3048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x294/0xb40 fs/hfsplus/extents.c:574 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&HFSPLUS_I(inode)->extents_lock); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz.0.0/5354: #0: ffff88801e7ee428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff8880530a3238 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:875 [inline] #1: ffff8880530a3238 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63 #2: ffff8880530a3048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x294/0xb40 fs/hfsplus/extents.c:574 #3: ffff88803f12c0f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_free+0xbe/0x550 fs/hfsplus/bitmap.c:182 stack backtrace: CPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 hfsplus_get_block+0x39e/0x1530 fs/hfsplus/extents.c:260 block_read_full_folio+0x29c/0x830 fs/buffer.c:2420 filemap_read_folio+0x114/0x380 mm/filemap.c:2413 do_read_cache_folio+0x350/0x590 mm/filemap.c:3957 do_read_cache_page mm/filemap.c:4023 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4032 read_mapping_page include/linux/pagemap.h:985 [inline] hfsplus_block_free+0x121/0x550 fs/hfsplus/bitmap.c:185 hfsplus_free_extents+0x441/0xa60 fs/hfsplus/extents.c:371 hfsplus_file_truncate+0x736/0xb40 fs/hfsplus/extents.c:589 hfsplus_setattr+0x1c4/0x270 fs/hfsplus/inode.c:266 notify_change+0xb33/0xe40 fs/attr.c:552 do_truncate+0x1a4/0x220 fs/open.c:68 vfs_truncate+0x493/0x520 fs/open.c:118 do_sys_truncate+0xdb/0x190 fs/open.c:141 __do_sys_truncate fs/open.c:153 [inline] __se_sys_truncate fs/open.c:151 [inline] __x64_sys_truncate+0x5b/0x70 fs/open.c:151 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f11ec18eba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f11e85ed038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f11ec3d5fa0 RCX: 00007f11ec18eba9 RDX: 0000000000000000 RSI: 00000000000000fe RDI: 00002000000000c0 RBP: 00007f11ec211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f11ec3d6038 R14: 00007f11ec3d5fa0 R15: 00007ffd86cfdeb8 hfsplus: unable to mark blocks free: error -5 hfsplus: can't free extent Zero length message leads to an empty skb