overlayfs: overlapping lowerdir path ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/22333 is trying to acquire lock: 00000000340fb45e (&ovl_i_mutex_dir_key[depth]#2){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 00000000340fb45e (&ovl_i_mutex_dir_key[depth]#2){++++}, at: do_last fs/namei.c:3326 [inline] 00000000340fb45e (&ovl_i_mutex_dir_key[depth]#2){++++}, at: path_openat+0x17ec/0x2df0 fs/namei.c:3537 but task is already holding lock: 0000000034da6133 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] 0000000034da6133 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sig->cred_guard_mutex){+.+.}: do_io_accounting fs/proc/base.c:2750 [inline] proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 __vfs_read+0xf7/0x750 fs/read_write.c:416 vfs_read+0x194/0x3c0 fs/read_write.c:452 ksys_read+0x12b/0x2a0 fs/read_write.c:579 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&p->lock){+.+.}: seq_read+0x6b/0x11c0 fs/seq_file.c:164 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_setattr+0xdd/0x920 fs/overlayfs/inode.c:30 notify_change+0x70b/0xfc0 fs/attr.c:334 chown_common+0x4a9/0x550 fs/open.c:651 do_fchownat+0x126/0x1e0 fs/open.c:681 __do_sys_lchown fs/open.c:706 [inline] __se_sys_lchown fs/open.c:704 [inline] __x64_sys_lchown+0x7a/0xc0 fs/open.c:704 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&ovl_i_mutex_dir_key[depth]#2){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &ovl_i_mutex_dir_key[depth]#2 --> &p->lock --> &sig->cred_guard_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sig->cred_guard_mutex); lock(&p->lock); lock(&sig->cred_guard_mutex); lock(&ovl_i_mutex_dir_key[depth]#2); *** DEADLOCK *** 1 lock held by syz-executor.0/22333: #0: 0000000034da6133 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] #0: 0000000034da6133 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 stack backtrace: CPU: 1 PID: 22333 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f03edacf279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f03ec444168 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007f03edbe1f80 RCX: 00007f03edacf279 RDX: 0000000020000b00 RSI: 0000000000000000 RDI: 00000000200005c0 RBP: 00007f03edb29189 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc351ed0df R14: 00007f03ec444300 R15: 0000000000022000 kauditd_printk_skb: 28 callbacks suppressed audit: type=1804 audit(1660549765.883:700): pid=22339 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir1869241854/syzkaller.rp6ngt/982/file0/bus" dev="sda1" ino=14102 res=1 MTD: Attempt to mount non-MTD device "/dev/loop0" romfs: VFS: Can't find a romfs filesystem on dev loop0. IPVS: ftp: loaded support on port[0] = 21 MTD: Attempt to mount non-MTD device "/dev/loop0" romfs: VFS: Can't find a romfs filesystem on dev loop0. MTD: Attempt to mount non-MTD device "/dev/loop0" romfs: VFS: Can't find a romfs filesystem on dev loop0. MTD: Attempt to mount non-MTD device "/dev/loop0" IPVS: ftp: loaded support on port[0] = 21 romfs: VFS: Can't find a romfs filesystem on dev loop0. caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect IPVS: ftp: loaded support on port[0] = 21 caif:caif_disconnect_client(): nothing to disconnect netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 audit: type=1800 audit(1660549772.464:701): pid=22871 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=14551 res=0 CPU: 1 PID: 22869 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc_trace+0x284/0x380 mm/slab.c:3623 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] alloc_pipe_info+0xb8/0x470 fs/pipe.c:662 splice_direct_to_actor+0x6dd/0x8d0 fs/splice.c:921 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f5415833279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54141a8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5415945f80 RCX: 00007f5415833279 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f54141a81d0 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000000016 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd09b261cf R14: 00007f54141a8300 R15: 0000000000022000 audit: type=1800 audit(1660549772.494:702): pid=22871 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=14551 res=0 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 22902 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] __do_kmalloc mm/slab.c:3725 [inline] __kmalloc+0x2ab/0x3c0 mm/slab.c:3736 kmalloc_array include/linux/slab.h:637 [inline] kcalloc include/linux/slab.h:648 [inline] alloc_pipe_info+0x193/0x470 fs/pipe.c:679 splice_direct_to_actor+0x6dd/0x8d0 fs/splice.c:921 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f5415833279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54141a8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5415945f80 RCX: 00007f5415833279 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f54141a81d0 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000000016 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd09b261cf R14: 00007f54141a8300 R15: 0000000000022000 audit: type=1800 audit(1660549773.064:703): pid=22909 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=14583 res=0 audit: type=1800 audit(1660549773.064:704): pid=22909 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=14583 res=0 audit: type=1800 audit(1660549773.404:705): pid=22955 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=14558 res=0 audit: type=1800 audit(1660549773.404:706): pid=22949 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=14558 res=0 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 22973 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc_node mm/slab.c:3304 [inline] kmem_cache_alloc_node_trace+0x244/0x3b0 mm/slab.c:3666 __do_kmalloc_node mm/slab.c:3688 [inline] __kmalloc_node+0x38/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:557 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] kvmalloc_array include/linux/mm.h:595 [inline] get_pages_array lib/iov_iter.c:1240 [inline] pipe_get_pages_alloc lib/iov_iter.c:1266 [inline] iov_iter_get_pages_alloc+0x562/0x1150 lib/iov_iter.c:1287 default_file_splice_read+0x191/0xa00 fs/splice.c:391 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f5415833279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54141a8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5415945f80 RCX: 00007f5415833279 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f54141a81d0 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000000016 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd09b261cf R14: 00007f54141a8300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 23001 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:3088 [inline] prepare_alloc_pages mm/page_alloc.c:4346 [inline] __alloc_pages_nodemask+0x239/0x2890 mm/page_alloc.c:4393 alloc_pages_current+0x193/0x2a0 mm/mempolicy.c:2197 alloc_pages include/linux/gfp.h:532 [inline] push_pipe+0x3e3/0x770 lib/iov_iter.c:515 __pipe_get_pages lib/iov_iter.c:1165 [inline] pipe_get_pages_alloc lib/iov_iter.c:1269 [inline] iov_iter_get_pages_alloc+0x5b1/0x1150 lib/iov_iter.c:1287 default_file_splice_read+0x191/0xa00 fs/splice.c:391 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f5415833279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54141a8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5415945f80 RCX: 00007f5415833279 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f54141a81d0 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000000016 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd09b261cf R14: 00007f54141a8300 R15: 0000000000022000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 23038 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0xf lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:3088 [inline] prepare_alloc_pages mm/page_alloc.c:4346 [inline] __alloc_pages_nodemask+0x239/0x2890 mm/page_alloc.c:4393 alloc_pages_current+0x193/0x2a0 mm/mempolicy.c:2197 alloc_pages include/linux/gfp.h:532 [inline] push_pipe+0x3e3/0x770 lib/iov_iter.c:515 __pipe_get_pages lib/iov_iter.c:1165 [inline] pipe_get_pages_alloc lib/iov_iter.c:1269 [inline] iov_iter_get_pages_alloc+0x5b1/0x1150 lib/iov_iter.c:1287 default_file_splice_read+0x191/0xa00 fs/splice.c:391 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f5415833279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f54141a8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5415945f80 RCX: 00007f5415833279 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000004