====================================================== WARNING: possible circular locking dependency detected 6.1.37-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/9059 is trying to acquire lock: ffff0000d62d3148 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x9c/0x124 mm/memory.c:5793 but task is already holding lock: ffff0000d8a220e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x144/0x2734 fs/exfat/dir.c:228 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sbi->s_lock#2){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 exfat_get_block+0x164/0x17ec fs/exfat/inode.c:281 block_read_full_folio+0x2f4/0x98c fs/buffer.c:2271 do_mpage_readpage+0x15a0/0x1748 fs/mpage.c:304 mpage_read_folio+0xec/0x1b4 fs/mpage.c:379 exfat_read_folio+0x28/0x38 fs/exfat/inode.c:339 filemap_read_folio+0x14c/0x39c mm/filemap.c:2407 filemap_update_page mm/filemap.c:2492 [inline] filemap_get_pages mm/filemap.c:2606 [inline] filemap_read+0x13ec/0x2260 mm/filemap.c:2676 generic_file_read_iter+0xa0/0x450 mm/filemap.c:2822 call_read_iter include/linux/fs.h:2199 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x5bc/0x8ac fs/read_write.c:470 ksys_read+0x15c/0x26c fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 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:581 -> #1 (mapping.invalidate_lock#5){.+.+}-{3:3}: down_read+0x64/0x308 kernel/locking/rwsem.c:1520 filemap_invalidate_lock_shared include/linux/fs.h:811 [inline] filemap_fault+0x58c/0xf7c mm/filemap.c:3128 __do_fault+0x11c/0x3d8 mm/memory.c:4224 do_read_fault mm/memory.c:4575 [inline] do_fault mm/memory.c:4704 [inline] handle_pte_fault mm/memory.c:4976 [inline] __handle_mm_fault mm/memory.c:5118 [inline] handle_mm_fault+0x1f68/0x3e9c mm/memory.c:5239 __do_page_fault arch/arm64/mm/fault.c:499 [inline] do_page_fault+0x330/0x890 arch/arm64/mm/fault.c:583 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:667 do_mem_abort+0x74/0x200 arch/arm64/mm/fault.c:803 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0x60/0xac arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x224/0x54c lib/strncpy_from_user.c:139 getname_flags+0x104/0x480 fs/namei.c:150 getname fs/namei.c:218 [inline] __do_sys_mkdirat fs/namei.c:4076 [inline] __se_sys_mkdirat fs/namei.c:4074 [inline] __arm64_sys_mkdirat+0x80/0xa8 fs/namei.c:4074 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 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:581 -> #0 (&mm->mmap_lock){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669 __might_fault+0xc4/0x124 mm/memory.c:5794 filldir64+0x2d4/0x948 fs/readdir.c:335 dir_emit_dot include/linux/fs.h:3583 [inline] dir_emit_dots include/linux/fs.h:3594 [inline] exfat_iterate+0x23c/0x2734 fs/exfat/dir.c:231 iterate_dir+0x1f4/0x4e4 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64 fs/readdir.c:354 [inline] __arm64_sys_getdents64+0x1c4/0x4a0 fs/readdir.c:354 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 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:581 other info that might help us debug this: Chain exists of: &mm->mmap_lock --> mapping.invalidate_lock#5 --> &sbi->s_lock#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_lock#2); lock(mapping.invalidate_lock#5); lock(&sbi->s_lock#2); lock(&mm->mmap_lock); *** DEADLOCK *** 3 locks held by syz-executor.4/9059: #0: ffff0000d29220e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xd8/0x104 fs/file.c:1047 #1: ffff00012735a330 (&sb->s_type->i_mutex_key#22){++++}-{3:3}, at: iterate_dir+0x124/0x4e4 fs/readdir.c:57 #2: ffff0000d8a220e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x144/0x2734 fs/exfat/dir.c:228 stack backtrace: CPU: 1 PID: 9059 Comm: syz-executor.4 Not tainted 6.1.37-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669 __might_fault+0xc4/0x124 mm/memory.c:5794 filldir64+0x2d4/0x948 fs/readdir.c:335 dir_emit_dot include/linux/fs.h:3583 [inline] dir_emit_dots include/linux/fs.h:3594 [inline] exfat_iterate+0x23c/0x2734 fs/exfat/dir.c:231 iterate_dir+0x1f4/0x4e4 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64 fs/readdir.c:354 [inline] __arm64_sys_getdents64+0x1c4/0x4a0 fs/readdir.c:354 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 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:581