====================================================== WARNING: possible circular locking dependency detected 5.2.0-rc2-next-20190531 #4 Not tainted ------------------------------------------------------ syz-executor.1/28460 is trying to acquire lock: 000000007749dcbb (&mm->mmap_sem#2){++++}, at: do_user_addr_fault arch/x86/mm/fault.c:1407 [inline] 000000007749dcbb (&mm->mmap_sem#2){++++}, at: __do_page_fault+0x9e9/0xda0 arch/x86/mm/fault.c:1522 but task is already holding lock: 000000000005b591 (&sb->s_type->i_mutex_key#10){++++}, at: inode_trylock include/linux/fs.h:798 [inline] 000000000005b591 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_file_write_iter+0x246/0x1070 fs/ext4/file.c:232 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#10){++++}: down_write+0x38/0xa0 kernel/locking/rwsem.c:66 inode_lock include/linux/fs.h:778 [inline] process_measurement+0x15ae/0x15e0 security/integrity/ima/ima_main.c:228 ima_file_mmap+0x11a/0x130 security/integrity/ima/ima_main.c:370 security_file_mprotect+0xd5/0x100 security/security.c:1430 do_mprotect_pkey+0x537/0xa30 mm/mprotect.c:550 __do_sys_pkey_mprotect mm/mprotect.c:590 [inline] __se_sys_pkey_mprotect mm/mprotect.c:587 [inline] __x64_sys_pkey_mprotect+0x97/0xf0 mm/mprotect.c:587 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&mm->mmap_sem#2){++++}: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4300 down_read+0x3f/0x1e0 kernel/locking/rwsem.c:24 do_user_addr_fault arch/x86/mm/fault.c:1407 [inline] __do_page_fault+0x9e9/0xda0 arch/x86/mm/fault.c:1522 do_page_fault+0x71/0x57d arch/x86/mm/fault.c:1553 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1156 fault_in_pages_readable include/linux/pagemap.h:600 [inline] iov_iter_fault_in_readable+0x377/0x450 lib/iov_iter.c:426 generic_perform_write+0x186/0x520 mm/filemap.c:3197 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3336 ext4_file_write_iter+0x332/0x1070 fs/ext4/file.c:266 call_write_iter include/linux/fs.h:1870 [inline] new_sync_write+0x4d3/0x770 fs/read_write.c:483 __vfs_write+0xe1/0x110 fs/read_write.c:496 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#10); lock(&mm->mmap_sem#2); lock(&sb->s_type->i_mutex_key#10); lock(&mm->mmap_sem#2); *** DEADLOCK *** 3 locks held by syz-executor.1/28460: #0: 00000000f0dc03f3 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 000000001d3176fb (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2836 [inline] #1: 000000001d3176fb (sb_writers#3){.+.+}, at: vfs_write+0x485/0x5d0 fs/read_write.c:557 #2: 000000000005b591 (&sb->s_type->i_mutex_key#10){++++}, at: inode_trylock include/linux/fs.h:798 [inline] #2: 000000000005b591 (&sb->s_type->i_mutex_key#10){++++}, at: ext4_file_write_iter+0x246/0x1070 fs/ext4/file.c:232 stack backtrace: CPU: 1 PID: 28460 Comm: syz-executor.1 Not tainted 5.2.0-rc2-next-20190531 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_circular_bug.cold+0x1cc/0x28f kernel/locking/lockdep.c:1566 check_prev_add kernel/locking/lockdep.c:2311 [inline] check_prevs_add kernel/locking/lockdep.c:2419 [inline] validate_chain kernel/locking/lockdep.c:2801 [inline] __lock_acquire+0x3755/0x5490 kernel/locking/lockdep.c:3790 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4300 down_read+0x3f/0x1e0 kernel/locking/rwsem.c:24 do_user_addr_fault arch/x86/mm/fault.c:1407 [inline] __do_page_fault+0x9e9/0xda0 arch/x86/mm/fault.c:1522 do_page_fault+0x71/0x57d arch/x86/mm/fault.c:1553 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1156 RIP: 0010:fault_in_pages_readable include/linux/pagemap.h:600 [inline] RIP: 0010:iov_iter_fault_in_readable+0x377/0x450 lib/iov_iter.c:426 Code: 89 f6 41 88 57 e0 e8 48 e5 3c fe 45 85 f6 74 c1 e9 70 fe ff ff e8 b9 e3 3c fe 0f 1f 00 0f ae e8 44 89 f0 48 8b 8d 68 ff ff ff <8a> 11 89 c3 0f 1f 00 41 88 57 d0 31 ff 89 de e8 15 e5 3c fe 85 db RSP: 0018:ffff88803dde7918 EFLAGS: 00010212 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000002008a17f RDX: 000000000003eb3f RSI: ffffffff833406b7 RDI: 0000000000000007 RBP: ffff88803dde79b8 R08: ffff8880a83d03c0 R09: 0000000000000004 R10: ffffed1015d26be7 R11: ffff8880ae935f3b R12: 0000000000001000 R13: 0000000000001000 R14: 0000000000000000 R15: ffff88803dde7990 generic_perform_write+0x186/0x520 mm/filemap.c:3197 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3336 ext4_file_write_iter+0x332/0x1070 fs/ext4/file.c:266 call_write_iter include/linux/fs.h:1870 [inline] new_sync_write+0x4d3/0x770 fs/read_write.c:483 __vfs_write+0xe1/0x110 fs/read_write.c:496 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f506babec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459279 RDX: 00000000fffffcad RSI: 0000000020000180 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f506babf6d4 R13: 00000000004c8838 R14: 00000000004df120 R15: 00000000ffffffff