====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc4-next-20240416-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/24233 is trying to acquire lock: ffff88805fead7a0 (&sb->s_type->i_mutex_key#29){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline] ffff88805fead7a0 (&sb->s_type->i_mutex_key#29){++++}-{3:3}, at: exfat_page_mkwrite+0x43a/0xea0 fs/exfat/file.c:629 but task is already holding lock: ffff88806c0ca518 (sb_pagefaults#8){.+.+}-{0:0}, at: do_page_mkwrite+0x19b/0x480 mm/memory.c:3097 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_pagefaults#8){.+.+}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1659 [inline] sb_start_pagefault include/linux/fs.h:1824 [inline] exfat_page_mkwrite+0x161/0xea0 fs/exfat/file.c:619 do_page_mkwrite+0x19b/0x480 mm/memory.c:3097 do_shared_fault mm/memory.c:4977 [inline] do_fault mm/memory.c:5039 [inline] do_pte_missing mm/memory.c:3881 [inline] handle_pte_fault+0x1298/0x6dc0 mm/memory.c:5359 __handle_mm_fault mm/memory.c:5500 [inline] handle_mm_fault+0x10e7/0x1bb0 mm/memory.c:5665 do_user_addr_fault arch/x86/mm/fault.c:1420 [inline] handle_page_fault arch/x86/mm/fault.c:1512 [inline] exc_page_fault+0x2b9/0x900 arch/x86/mm/fault.c:1570 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 -> #1 (&mm->mmap_lock){++++}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 gup_fast_fallback+0x24c/0x2b40 mm/gup.c:3442 pin_user_pages_fast+0xcc/0x160 mm/gup.c:3566 iov_iter_extract_user_pages lib/iov_iter.c:1583 [inline] iov_iter_extract_pages+0x3db/0x720 lib/iov_iter.c:1646 dio_refill_pages fs/direct-io.c:173 [inline] dio_get_page fs/direct-io.c:214 [inline] do_direct_IO fs/direct-io.c:916 [inline] __blockdev_direct_IO+0x150a/0x49b0 fs/direct-io.c:1249 blockdev_direct_IO include/linux/fs.h:3182 [inline] exfat_direct_IO+0x1b4/0x3d0 fs/exfat/inode.c:526 generic_file_read_iter+0x231/0x430 mm/filemap.c:2783 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9c4/0xbd0 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sb->s_type->i_mutex_key#29){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_write+0x3a/0x50 kernel/locking/rwsem.c:1579 inode_lock include/linux/fs.h:791 [inline] exfat_page_mkwrite+0x43a/0xea0 fs/exfat/file.c:629 do_page_mkwrite+0x19b/0x480 mm/memory.c:3097 do_shared_fault mm/memory.c:4977 [inline] do_fault mm/memory.c:5039 [inline] do_pte_missing mm/memory.c:3881 [inline] handle_pte_fault+0x1298/0x6dc0 mm/memory.c:5359 __handle_mm_fault mm/memory.c:5500 [inline] handle_mm_fault+0x10e7/0x1bb0 mm/memory.c:5665 do_user_addr_fault arch/x86/mm/fault.c:1420 [inline] handle_page_fault arch/x86/mm/fault.c:1512 [inline] exc_page_fault+0x2b9/0x900 arch/x86/mm/fault.c:1570 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#29 --> &mm->mmap_lock --> sb_pagefaults#8 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#8); lock(&mm->mmap_lock); lock(sb_pagefaults#8); lock(&sb->s_type->i_mutex_key#29); *** DEADLOCK *** 2 locks held by syz-executor.1/24233: #0: ffff888061697398 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff888061697398 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5692 [inline] #0: ffff888061697398 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5752 #1: ffff88806c0ca518 (sb_pagefaults#8){.+.+}-{0:0}, at: do_page_mkwrite+0x19b/0x480 mm/memory.c:3097 stack backtrace: CPU: 0 PID: 24233 Comm: syz-executor.1 Not tainted 6.9.0-rc4-next-20240416-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_write+0x3a/0x50 kernel/locking/rwsem.c:1579 inode_lock include/linux/fs.h:791 [inline] exfat_page_mkwrite+0x43a/0xea0 fs/exfat/file.c:629 do_page_mkwrite+0x19b/0x480 mm/memory.c:3097 do_shared_fault mm/memory.c:4977 [inline] do_fault mm/memory.c:5039 [inline] do_pte_missing mm/memory.c:3881 [inline] handle_pte_fault+0x1298/0x6dc0 mm/memory.c:5359 __handle_mm_fault mm/memory.c:5500 [inline] handle_mm_fault+0x10e7/0x1bb0 mm/memory.c:5665 do_user_addr_fault arch/x86/mm/fault.c:1420 [inline] handle_page_fault arch/x86/mm/fault.c:1512 [inline] exc_page_fault+0x2b9/0x900 arch/x86/mm/fault.c:1570 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fe639427006 Code: d0 44 0f b6 52 15 49 c1 e2 34 4c 09 d0 44 0f b6 52 13 0f b6 52 11 49 c1 e2 35 48 c1 e2 36 4c 09 d0 48 09 d0 4c 09 c8 4c 09 c0 <48> 89 04 cf 48 89 04 ce c3 90 48 89 7c 24 f8 48 89 74 24 f0 31 f6 RSP: 002b:00007fe63a106578 EFLAGS: 00010202 RAX: 00008f0000509120 RBX: 000000000000000f RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000020003800 RDI: 0000000020003800 RBP: 0000000020001000 R08: 0000000000009120 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: 00007fe63a106a30 R14: 0000000020000000 R15: 0000000020001800