============================================ WARNING: possible recursive locking detected 6.1.137-syzkaller #0 Not tainted -------------------------------------------- syz.0.375/6173 is trying to acquire lock: ffff0000f4719c08 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x2bc/0x1154 fs/hfsplus/extents.c:260 but task is already holding lock: ffff0000f471b708 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x180/0x1324 fs/hfsplus/extents.c:458 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.0.375/6173: #0: ffff0000ce9a4460 (sb_writers#30){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:933 [inline] #0: ffff0000ce9a4460 (sb_writers#30){.+.+}-{0:0}, at: do_pwritev+0x1b4/0x2fc fs/read_write.c:1031 #1: ffff0000f471b900 (&sb->s_type->i_mutex_key#35){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000f471b900 (&sb->s_type->i_mutex_key#35){+.+.}-{3:3}, at: generic_file_write_iter+0x84/0x2b0 mm/filemap.c:4003 #2: ffff0000f471b708 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x180/0x1324 fs/hfsplus/extents.c:458 #3: ffff0000d1b7d8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x88/0x7d8 fs/hfsplus/bitmap.c:35 stack backtrace: CPU: 1 PID: 6173 Comm: syz.0.375 Not tainted 6.1.137-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 __lock_acquire+0x18b4/0x6544 kernel/locking/lockdep.c:-1 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x1f38 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hfsplus_get_block+0x2bc/0x1154 fs/hfsplus/extents.c:260 block_read_full_folio+0x2e4/0x97c fs/buffer.c:2271 hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28 filemap_read_folio+0x130/0x37c mm/filemap.c:2490 do_read_cache_folio+0x24c/0x544 mm/filemap.c:3627 do_read_cache_page mm/filemap.c:3669 [inline] read_cache_page+0x6c/0x184 mm/filemap.c:3678 read_mapping_page include/linux/pagemap.h:791 [inline] hfsplus_block_allocate+0xdc/0x7d8 fs/hfsplus/bitmap.c:37 hfsplus_file_extend+0x73c/0x1324 fs/hfsplus/extents.c:469 hfsplus_get_block+0x314/0x1154 fs/hfsplus/extents.c:245 __block_write_begin_int+0x34c/0x13b8 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin fs/buffer.c:2102 [inline] cont_write_begin+0x548/0x780 fs/buffer.c:2456 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 cont_expand_zero fs/buffer.c:2416 [inline] cont_write_begin+0x5e0/0x780 fs/buffer.c:2446 hfsplus_write_begin+0x98/0xe4 fs/hfsplus/inode.c:52 generic_perform_write+0x230/0x4b0 mm/filemap.c:3846 __generic_file_write_iter+0x168/0x37c mm/filemap.c:3974 generic_file_write_iter+0xb4/0x2b0 mm/filemap.c:4006 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x530/0x91c fs/read_write.c:861 vfs_writev fs/read_write.c:934 [inline] do_pwritev+0x1c8/0x2fc fs/read_write.c:1031 __do_sys_pwritev2 fs/read_write.c:1090 [inline] __se_sys_pwritev2 fs/read_write.c:1081 [inline] __arm64_sys_pwritev2+0xd4/0x108 fs/read_write.c:1081 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585