======================================================= ============================================ WARNING: possible recursive locking detected 6.9.0-rc7-syzkaller-00188-gba16c1cf11c9 #0 Not tainted -------------------------------------------- syz-executor861/5072 is trying to acquire lock: ffff88807e97c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x16e/0x1f0 but task is already holding lock: ffff88807e97c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x16e/0x1f0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&tree->tree_lock/1); lock(&tree->tree_lock/1); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor861/5072: #0: ffff88807e97a420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2855 [inline] #0: ffff88807e97a420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 #1: ffff8880244b9628 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline] #1: ffff8880244b9628 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x310 mm/filemap.c:4092 #2: ffff8880244b9478 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1450 fs/hfs/extent.c:397 #3: ffff88807e97c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x16e/0x1f0 #4: ffff8880244b80f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1450 fs/hfs/extent.c:397 stack backtrace: CPU: 1 PID: 5072 Comm: syz-executor861 Not tainted 6.9.0-rc7-syzkaller-00188-gba16c1cf11c9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 hfs_find_init+0x16e/0x1f0 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x31b/0x1450 fs/hfs/extent.c:401 hfs_bmap_reserve+0xd9/0x400 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x22e/0x4f0 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6a/0x990 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x344/0x1450 fs/hfs/extent.c:401 hfs_get_block+0x3e4/0xb60 fs/hfs/extent.c:353 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2105 __block_write_begin fs/buffer.c:2154 [inline] block_write_begin+0x9b/0x1e0 fs/buffer.c:2213 cont_write_begin+0x645/0x890 fs/buffer.c:2567 hfs_write_begin+0x8a/0xd0 fs/hfs/inode.c:53 generic_perform_write+0x322/0x640 mm/filemap.c:3974 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4095 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2ca82c7a39 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe7ffb83e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2ca831004b RCX: 00007f2ca82c7a39 RDX: 0000003e03000000 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00007f2ca833a610 R08: 0000000000000000 R09: 00007ffe7ffb85b8 R10: 00000000000002db R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffe7ffb85a8 R14: 0000000000000001 R15: 0000000000000001