====================================================== WARNING: possible circular locking dependency detected 5.15.189-syzkaller #0 Not tainted ------------------------------------------------------ syz.5.906/8234 is trying to acquire lock: ffff8880252d22c8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x39b/0x1530 fs/hfsplus/extents.c:260 but task is already holding lock: ffff88805c2c68f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x91/0x900 fs/hfsplus/bitmap.c:35 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->alloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 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+0x91/0x900 fs/hfsplus/bitmap.c:35 hfsplus_file_extend+0xa8e/0x1950 fs/hfsplus/extents.c:469 hfsplus_bmap_reserve+0x11e/0x4f0 fs/hfsplus/btree.c:357 hfsplus_create_cat+0x180/0x1020 fs/hfsplus/catalog.c:272 hfsplus_fill_super+0x12f6/0x1b90 fs/hfsplus/super.c:560 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3014 do_mount fs/namespace.c:3357 [inline] __do_sys_mount fs/namespace.c:3565 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3542 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 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 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+0x39b/0x1530 fs/hfsplus/extents.c:260 block_read_full_page+0x2e8/0xd10 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+0xf4/0x900 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa8e/0x1950 fs/hfsplus/extents.c:469 hfsplus_get_block+0x40e/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x58a/0x7b0 fs/buffer.c:2471 hfsplus_write_begin+0x92/0xe0 fs/hfsplus/inode.c:53 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 __kernel_write+0x4f9/0x930 fs/read_write.c:539 __dump_emit+0x243/0x360 fs/coredump.c:943 elf_core_dump+0x27b4/0x3530 fs/binfmt_elf.c:2237 do_coredump+0x1419/0x2960 fs/coredump.c:894 get_signal+0x40a/0x12c0 kernel/signal.c:2886 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock( &sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); lock(&sbi->alloc_mutex); lock(&HFSPLUS_I(inode)->extents_lock); *** DEADLOCK *** 4 locks held by syz.5.906/8234: #0: ffff888023e28460 (sb_writers#20){.+.+}-{0:0}, at: do_coredump+0x13fd/0x2960 fs/coredump.c:893 #1: ffff8880252d6180 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff8880252d6180 (&sb->s_type->i_mutex_key#26){+.+.}-{3:3}, at: generic_file_write_iter+0x7e/0x1b0 mm/filemap.c:3941 #2: ffff8880252d5f88 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1b3/0x1950 fs/hfsplus/extents.c:458 #3: ffff88805c2c68f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x91/0x900 fs/hfsplus/bitmap.c:35 stack backtrace: CPU: 0 PID: 8234 Comm: syz.5.906 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 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+0x39b/0x1530 fs/hfsplus/extents.c:260 block_read_full_page+0x2e8/0xd10 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+0xf4/0x900 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0xa8e/0x1950 fs/hfsplus/extents.c:469 hfsplus_get_block+0x40e/0x1530 fs/hfsplus/extents.c:245 __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin fs/buffer.c:2122 [inline] cont_write_begin+0x58a/0x7b0 fs/buffer.c:2471 hfsplus_write_begin+0x92/0xe0 fs/hfsplus/inode.c:53 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 __kernel_write+0x4f9/0x930 fs/read_write.c:539 __dump_emit+0x243/0x360 fs/coredump.c:943 elf_core_dump+0x27b4/0x3530 fs/binfmt_elf.c:2237 do_coredump+0x1419/0x2960 fs/coredump.c:894 get_signal+0x40a/0x12c0 kernel/signal.c:2886 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x3592bbe8 Code: Unable to access opcode bytes at RIP 0x3592bbbe. RSP: 002b:0000200000000488 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fc79ac6cfa0 RCX: 00007fc79aa45b69 RDX: 0000200000000180 RSI: 0000200000000480 RDI: 0000000002000000 RBP: 00007fc79aac8df1 R08: 00002000000004c0 R09: 00002000000004c0 R10: 0000200000000200 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc79ac6cfa0 R15: 00007ffed35b4dc8