====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.239/5053 is trying to acquire lock: ffff88807ddfb0f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x93/0x910 fs/hfsplus/bitmap.c:35 but task is already holding lock: ffff88807ea7e648 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}: __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_get_block+0x3a1/0x15a0 fs/hfsplus/extents.c:260 block_read_full_page+0x306/0xd40 fs/buffer.c:2290 do_read_cache_page+0x8a1/0x1030 mm/filemap.c:-1 read_mapping_page include/linux/pagemap.h:515 [inline] hfsplus_block_allocate+0xf1/0x910 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xb1f/0x1a50 fs/hfsplus/extents.c:466 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x598/0x7b0 fs/buffer.c:2471 hfsplus_write_begin+0x92/0xe0 fs/hfsplus/inode.c:53 __page_symlink+0x102/0x200 fs/namei.c:5199 hfsplus_symlink+0xc6/0x260 fs/hfsplus/dir.c:449 vfs_symlink+0x247/0x3d0 fs/namei.c:4437 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4466 __do_sys_symlink fs/namei.c:4488 [inline] __se_sys_symlink fs/namei.c:4486 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sbi->alloc_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_block_allocate+0x93/0x910 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb1f/0x1a50 fs/hfsplus/extents.c:466 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 get_more_blocks fs/direct-io.c:673 [inline] do_direct_IO fs/direct-io.c:959 [inline] do_blockdev_direct_IO fs/direct-io.c:1276 [inline] __blockdev_direct_IO+0x13d4/0x3a70 fs/direct-io.c:1368 blockdev_direct_IO include/linux/fs.h:3345 [inline] hfsplus_direct_IO+0x119/0x220 fs/hfsplus/inode.c:135 generic_file_direct_write+0x22c/0x490 mm/filemap.c:3687 __generic_file_write_iter+0x2b1/0x4e0 mm/filemap.c:3869 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1 do_iter_write+0x205/0x7b0 fs/read_write.c:855 vfs_writev fs/read_write.c:928 [inline] do_writev+0x281/0x480 fs/read_write.c:971 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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 *** 4 locks held by syz.1.239/5053: #0: ffff8880795fc5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff888075faa460 (sb_writers#19){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:927 [inline] #1: ffff888075faa460 (sb_writers#19){.+.+}-{0:0}, at: do_writev+0x263/0x480 fs/read_write.c:971 #2: ffff88807ea7e840 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #2: ffff88807ea7e840 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: generic_file_write_iter+0x7e/0x1b0 mm/filemap.c:3941 #3: ffff88807ea7e648 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1cd/0x1a50 fs/hfsplus/extents.c:455 stack backtrace: CPU: 1 PID: 5053 Comm: syz.1.239 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_block_allocate+0x93/0x910 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xb1f/0x1a50 fs/hfsplus/extents.c:466 hfsplus_get_block+0x430/0x15a0 fs/hfsplus/extents.c:245 get_more_blocks fs/direct-io.c:673 [inline] do_direct_IO fs/direct-io.c:959 [inline] do_blockdev_direct_IO fs/direct-io.c:1276 [inline] __blockdev_direct_IO+0x13d4/0x3a70 fs/direct-io.c:1368 blockdev_direct_IO include/linux/fs.h:3345 [inline] hfsplus_direct_IO+0x119/0x220 fs/hfsplus/inode.c:135 generic_file_direct_write+0x22c/0x490 mm/filemap.c:3687 __generic_file_write_iter+0x2b1/0x4e0 mm/filemap.c:3869 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1 do_iter_write+0x205/0x7b0 fs/read_write.c:855 vfs_writev fs/read_write.c:928 [inline] do_writev+0x281/0x480 fs/read_write.c:971 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc8e2912dd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc8e0b6c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fc8e2b8bfa0 RCX: 00007fc8e2912dd9 RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000004 RBP: 00007fc8e29a8d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc8e2b8c038 R14: 00007fc8e2b8bfa0 R15: 00007ffc2a7cf0b8