====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.355/11200 is trying to acquire lock: ffff8880290f68e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xd10 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff888027c70878 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1c40 fs/hfsplus/extents.c:453 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552 hfsplus_get_block+0x39a/0x1600 fs/hfsplus/extents.c:260 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420 filemap_read_folio+0x117/0x380 mm/filemap.c:2496 do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4096 do_read_cache_page mm/filemap.c:4162 [inline] read_cache_page+0x5d/0x170 mm/filemap.c:4171 read_mapping_page include/linux/pagemap.h:1011 [inline] hfsplus_block_allocate+0xf3/0xd10 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa9a/0x1c40 fs/hfsplus/extents.c:464 hfsplus_get_block+0x40c/0x1600 fs/hfsplus/extents.c:245 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145 block_write_begin fs/buffer.c:2256 [inline] cont_write_begin+0x78c/0xb50 fs/buffer.c:2594 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48 page_symlink+0x26f/0x430 fs/namei.c:6277 hfsplus_symlink+0xca/0x260 fs/hfsplus/dir.c:449 vfs_symlink+0x29a/0x2d0 fs/namei.c:5514 do_symlinkat+0x1f5/0x3d0 fs/namei.c:5541 __do_sys_symlink fs/namei.c:5567 [inline] __se_sys_symlink fs/namei.c:5565 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:5565 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sbi->alloc_mutex){+.+.}-{4:4}: 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552 hfsplus_block_allocate+0xa7/0xd10 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xa9a/0x1c40 fs/hfsplus/extents.c:464 hfsplus_get_block+0x40c/0x1600 fs/hfsplus/extents.c:245 get_more_blocks fs/direct-io.c:648 [inline] do_direct_IO fs/direct-io.c:936 [inline] __blockdev_direct_IO+0x157c/0x31f0 fs/direct-io.c:1243 blockdev_direct_IO include/linux/fs.h:3075 [inline] hfsplus_direct_IO+0x11b/0x220 fs/hfsplus/inode.c:131 generic_file_direct_write+0x1dc/0x3e0 mm/filemap.c:4248 __generic_file_write_iter+0x120/0x240 mm/filemap.c:4417 generic_file_write_iter+0x118/0x550 mm/filemap.c:4457 iter_file_splice_write+0x977/0x10b0 fs/splice.c:738 do_splice_from fs/splice.c:938 [inline] direct_splice_actor+0x104/0x160 fs/splice.c:1161 splice_direct_to_actor+0x5b3/0xcd0 fs/splice.c:1105 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x187/0x270 fs/splice.c:1230 do_sendfile+0x4ec/0x7f0 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); *** DEADLOCK *** 3 locks held by syz.5.355/11200: #0: ffff88803707a480 (sb_writers#21){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160 #1: ffff888027c70ad8 (&sb->s_type->i_mutex_key#45){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888027c70ad8 (&sb->s_type->i_mutex_key#45){+.+.}-{4:4}, at: generic_file_write_iter+0xec/0x550 mm/filemap.c:4454 #2: ffff888027c70878 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1c40 fs/hfsplus/extents.c:453 stack backtrace: CPU: 1 UID: 0 PID: 11200 Comm: syz.5.355 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552 hfsplus_block_allocate+0xa7/0xd10 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xa9a/0x1c40 fs/hfsplus/extents.c:464 hfsplus_get_block+0x40c/0x1600 fs/hfsplus/extents.c:245 get_more_blocks fs/direct-io.c:648 [inline] do_direct_IO fs/direct-io.c:936 [inline] __blockdev_direct_IO+0x157c/0x31f0 fs/direct-io.c:1243 blockdev_direct_IO include/linux/fs.h:3075 [inline] hfsplus_direct_IO+0x11b/0x220 fs/hfsplus/inode.c:131 generic_file_direct_write+0x1dc/0x3e0 mm/filemap.c:4248 __generic_file_write_iter+0x120/0x240 mm/filemap.c:4417 generic_file_write_iter+0x118/0x550 mm/filemap.c:4457 iter_file_splice_write+0x977/0x10b0 fs/splice.c:738 do_splice_from fs/splice.c:938 [inline] direct_splice_actor+0x104/0x160 fs/splice.c:1161 splice_direct_to_actor+0x5b3/0xcd0 fs/splice.c:1105 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x187/0x270 fs/splice.c:1230 do_sendfile+0x4ec/0x7f0 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1431 [inline] __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6e7436f749 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:00007f6e725ce038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f6e745c5fa0 RCX: 00007f6e7436f749 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000006 RBP: 00007f6e743f3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6e745c6038 R14: 00007f6e745c5fa0 R15: 00007ffd5ed6afa8