memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=5970 'syz-executor198' loop0: detected capacity change from 0 to 64 ============================================ WARNING: possible recursive locking detected 6.4.0-rc5-syzkaller-g177239177378 #0 Not tainted -------------------------------------------- syz-executor198/5970 is trying to acquire lock: ffff0000de4c60b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 but task is already holding lock: ffff0000de4c60b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 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-executor198/5970: #0: ffff0000de4c4460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x240/0x918 fs/read_write.c:580 #1: ffff0000de4a1628 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline] #1: ffff0000de4a1628 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: generic_file_write_iter+0x88/0x2b4 mm/filemap.c:4080 #2: ffff0000de4a1478 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 #3: ffff0000de4c60b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 #4: ffff0000de4a00f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397 stack backtrace: CPU: 1 PID: 5970 Comm: syz-executor198 Not tainted 6.4.0-rc5-syzkaller-g177239177378 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 dump_stack+0x1c/0x28 lib/dump_stack.c:113 __lock_acquire+0x62b8/0x7604 lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5705 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799 hfs_find_init+0x148/0x1c8 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x270/0x1130 fs/hfs/extent.c:401 hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234 __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x84/0x754 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x29c/0x1130 fs/hfs/extent.c:401 hfs_get_block+0x3b8/0x9e0 fs/hfs/extent.c:353 __block_write_begin_int+0x460/0x1790 fs/buffer.c:2064 __block_write_begin fs/buffer.c:2114 [inline] block_write_begin fs/buffer.c:2175 [inline] cont_write_begin+0x7b8/0xc78 fs/buffer.c:2534 hfs_write_begin+0x98/0xe4 fs/hfs/inode.c:58 generic_perform_write+0x278/0x55c mm/filemap.c:3923 __generic_file_write_iter+0x168/0x388 mm/filemap.c:4051 generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:4083 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x618/0x918 fs/read_write.c:584 ksys_write+0x15c/0x26c fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191 el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591