Hello, syzbot found the following issue on: HEAD commit: 66e4190e92ce Add linux-next specific files for 20240416 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=15817767180000 kernel config: https://syzkaller.appspot.com/x/.config?x=c247afaa437e6409 dashboard link: https://syzkaller.appspot.com/bug?extid=d88216a7af9446d57d59 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/86891dae5f9c/disk-66e4190e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1ca383660bf2/vmlinux-66e4190e.xz kernel image: https://storage.googleapis.com/syzbot-assets/bf6ff37d3fcc/bzImage-66e4190e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d88216a7af9446d57d59@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc4-next-20240416-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/17125 is trying to acquire lock: ffff88805e616b38 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline] ffff88805e616b38 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: exfat_page_mkwrite+0x43a/0xea0 fs/exfat/file.c:629 but task is already holding lock: ffff88802dc76518 (sb_pagefaults#4){.+.+}-{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#4){.+.+}-{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 __put_user_4+0x11/0x20 arch/x86/lib/putuser.S:86 __sys_socketpair+0x186/0x720 net/socket.c:1756 __do_sys_socketpair net/socket.c:1822 [inline] __se_sys_socketpair net/socket.c:1819 [inline] __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819 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 -> #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#24){++++}-{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#24 --> &mm->mmap_lock --> sb_pagefaults#4 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#4); lock(&mm->mmap_lock); lock(sb_pagefaults#4); lock(&sb->s_type->i_mutex_key#24); *** DEADLOCK *** 2 locks held by syz-executor.0/17125: #0: ffff88804e4ce098 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88804e4ce098 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5692 [inline] #0: ffff88804e4ce098 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5752 #1: ffff88802dc76518 (sb_pagefaults#4){.+.+}-{0:0}, at: do_page_mkwrite+0x19b/0x480 mm/memory.c:3097 stack backtrace: CPU: 1 PID: 17125 Comm: syz-executor.0 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: <TASK> __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: 0033:0x7f59f325f107 Code: 7e 6f 44 16 e0 48 29 fe 48 83 e1 e0 48 01 ce 0f 1f 40 00 c5 fe 6f 4e 60 c5 fe 6f 56 40 c5 fe 6f 5e 20 c5 fe 6f 26 48 83 c6 80 <c5> fd 7f 49 60 c5 fd 7f 51 40 c5 fd 7f 59 20 c5 fd 7f 21 48 83 c1 RSP: 002b:00007ffd52a03428 EFLAGS: 00010203 RAX: 00000000200027c0 RBX: 0000000000000004 RCX: 0000000020003c20 RDX: 0000000000001500 RSI: 00007f59f2e02adf RDI: 00000000200027c0 RBP: 00007f59f33ac050 R08: 0000000000000000 R09: 0000000000000054 R10: 0000000000000000 R11: 0000000000000001 R12: 00007ffd52a035e0 R13: 0000000000000001 R14: ffffffffffffffff R15: 00007f59f3234cb0 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
