====================================================== WARNING: possible circular locking dependency detected 4.14.0-next-20171124+ #51 Not tainted ------------------------------------------------------ syz-executor6/10522 is trying to acquire lock: (console_lock){+.+.}, at: [] vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:75 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&pipe->mutex/1){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 pipe_lock_nested fs/pipe.c:67 [inline] pipe_lock+0x56/0x70 fs/pipe.c:75 iter_file_splice_write+0x264/0xf30 fs/splice.c:699 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #2 (sb_writers){.+.+}: complete+0x18/0x80 kernel/sched/completion.c:35 -> #1 ((completion)&req.done){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 complete_acquire include/linux/completion.h:40 [inline] __wait_for_common kernel/sched/completion.c:109 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144 devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115 device_add+0x120f/0x1640 drivers/base/core.c:1824 device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430 device_create_vargs drivers/base/core.c:2470 [inline] device_create+0xda/0x110 drivers/base/core.c:2506 vcs_make_sysfs+0x35/0x60 drivers/tty/vt/vc_screen.c:629 vc_allocate+0x4b7/0x6b0 drivers/tty/vt/vt.c:797 con_install+0x52/0x440 drivers/tty/vt/vt.c:2876 tty_driver_install_tty drivers/tty/tty_io.c:1215 [inline] tty_init_dev+0xf6/0x4a0 drivers/tty/tty_io.c:1315 tty_open_by_driver drivers/tty/tty_io.c:1942 [inline] tty_open+0x608/0xab0 drivers/tty/tty_io.c:1990 chrdev_open+0x257/0x730 fs/char_dev.c:417 do_dentry_open+0x682/0xd70 fs/open.c:752 vfs_open+0x107/0x230 fs/open.c:866 do_last fs/namei.c:3388 [inline] path_openat+0x1157/0x3530 fs/namei.c:3528 do_filp_open+0x25b/0x3b0 fs/namei.c:3563 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #0 (console_lock){+.+.}: check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 console_lock+0x4b/0x80 kernel/printk/printk.c:2047 vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 __vfs_write+0xef/0x970 fs/read_write.c:480 __kernel_write+0xfe/0x350 fs/read_write.c:501 write_pipe_buf+0x175/0x220 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x328/0x730 fs/splice.c:626 splice_from_pipe+0x1e9/0x330 fs/splice.c:661 default_file_splice_write+0x40/0x90 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0x96 other info that might help us debug this: Chain exists of: console_lock --> sb_writers --> &pipe->mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex/1); lock(sb_writers); lock(&pipe->mutex/1); lock(console_lock); *** DEADLOCK *** 1 lock held by syz-executor6/10522: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:75 stack backtrace: CPU: 0 PID: 10522 Comm: syz-executor6 Not tainted 4.14.0-next-20171124+ #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_circular_bug+0x42d/0x610 kernel/locking/lockdep.c:1271 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914 check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 console_lock+0x4b/0x80 kernel/printk/printk.c:2047 vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 __vfs_write+0xef/0x970 fs/read_write.c:480 __kernel_write+0xfe/0x350 fs/read_write.c:501 write_pipe_buf+0x175/0x220 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x328/0x730 fs/splice.c:626 splice_from_pipe+0x1e9/0x330 fs/splice.c:661 default_file_splice_write+0x40/0x90 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007f7dc6dffbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000014 RBP: 0000000000000086 R08: 00000000fffff5fc R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2608 R13: 00000000ffffffff R14: 00007f7dc6e006d4 R15: 0000000000000000 sctp: [Deprecated]: syz-executor7 (pid 10586) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor7 (pid 10586) Use of int in maxseg socket option. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor7 (pid 10595) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor7 (pid 10595) Use of int in maxseg socket option. Use struct sctp_assoc_value instead QAT: Invalid ioctl netlink: 5 bytes leftover after parsing attributes in process `syz-executor4'. QAT: Invalid ioctl netlink: 5 bytes leftover after parsing attributes in process `syz-executor4'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'. device lo entered promiscuous mode kvm [10797]: vcpu4, guest rIP: 0xfff0 unimplemented MMIO_CONF_BASE wrmsr: 0x3e2d device lo left promiscuous mode kvm [10797]: vcpu4, guest rIP: 0xfff0 unimplemented MMIO_CONF_BASE wrmsr: 0x3e2d kauditd_printk_skb: 481 callbacks suppressed audit: type=1326 audit(1511513888.875:2417): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10827 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=c000003e syscall=54 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513888.876:2418): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10827 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513888.876:2419): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10827 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513888.978:2420): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513889.001:2421): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=257 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513889.002:2422): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513889.003:2423): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=54 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513889.003:2424): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513889.003:2425): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=72 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511513889.003:2426): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10860 comm="syz-executor1" exe="/root/syz-executor1" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 QAT: Invalid ioctl QAT: Invalid ioctl pit: kvm: requested 5866 ns i8254 timer period limited to 500000 ns rfkill: input handler disabled rfkill: input handler enabled device gre0 entered promiscuous mode nla_parse: 1 callbacks suppressed netlink: 4 bytes leftover after parsing attributes in process `syz-executor5'. kvm [11381]: vcpu0, guest rIP: 0xfff0 ignored wrmsr: 0x11e data 0x0 kvm [11381]: vcpu0, guest rIP: 0xfff0 ignored wrmsr: 0x11e data 0x0 dccp_v4_rcv: dropped packet with invalid checksum dccp_v4_rcv: dropped packet with invalid checksum device gre0 entered promiscuous mode kvm: apic: phys broadcast and lowest prio kvm: apic: phys broadcast and lowest prio netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'. device eql entered promiscuous mode syz-executor4: vmalloc: allocation failure: 12550406144 bytes, mode:0x14080c0(GFP_KERNEL|__GFP_ZERO), nodemask=(null) Empty option to dns_resolver key syz-executor4 cpuset=/ mems_allowed=0 CPU: 1 PID: 11700 Comm: syz-executor4 Not tainted 4.14.0-next-20171124+ #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 syz-executor4: vmalloc: allocation failure: 12550406144 bytes, mode:0x14080c0(GFP_KERNEL|__GFP_ZERO), nodemask=(null) syz-executor4 cpuset=/ mems_allowed=0 warn_alloc+0x19a/0x2b0 mm/page_alloc.c:3294 __vmalloc_node_range+0x4f0/0x650 mm/vmalloc.c:1775 __vmalloc_node mm/vmalloc.c:1804 [inline] __vmalloc_node_flags_caller+0x50/0x60 mm/vmalloc.c:1826 kvmalloc_node+0x82/0xd0 mm/util.c:406 kvmalloc include/linux/mm.h:541 [inline] kvmalloc_array include/linux/mm.h:557 [inline] xt_alloc_entry_offsets+0x21/0x30 net/netfilter/x_tables.c:774 translate_table+0x235/0x1610 net/ipv4/netfilter/ip_tables.c:685 do_replace net/ipv4/netfilter/ip_tables.c:1148 [inline] do_ipt_set_ctl+0x34b/0x5c0 net/ipv4/netfilter/ip_tables.c:1682 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0xa1/0xb0 net/ipv4/ip_sockglue.c:1256 raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:850 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968 SYSC_setsockopt net/socket.c:1851 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1830 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007f05746acbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000018 RBP: 00000000204f7000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020002000 R11: 0000000000000212 R12: 00000000006f53c8 R13: 00000000ffffffff R14: 00007f05746ad6d4 R15: 0000000000000000 CPU: 0 PID: 11718 Comm: syz-executor4 Not tainted 4.14.0-next-20171124+ #51 Mem-Info: active_anon:136082 inactive_anon:34 isolated_anon:0 active_file:3677 inactive_file:8377 isolated_file:0 unevictable:2 dirty:138 writeback:0 unstable:0 slab_reclaimable:7686 slab_unreclaimable:99424 mapped:22856 shmem:61 pagetables:946 bounce:0 free:1351815 free_pcp:383 free_cma:0 Node 0 active_anon:544328kB inactive_anon:136kB active_file:14708kB inactive_file:33508kB unevictable:8kB isolated(anon):0kB isolated(file):0kB mapped:91424kB dirty:552kB writeback:0kB shmem:244kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 63488kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no Node 0 DMA free:15908kB min:160kB low:200kB high:240kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 2882 6395 6395 Node 0 DMA32 free:2953236kB min:30384kB low:37980kB high:45576kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129332kB managed:2954000kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:760kB local_pcp:608kB free_cma:0kB lowmem_reserve[]: 0 0 3513 3513 Node 0 Normal free:2438116kB min:37032kB low:46288kB high:55544kB active_anon:544328kB inactive_anon:136kB active_file:14708kB inactive_file:33508kB unevictable:8kB writepending:552kB present:4718592kB managed:3597644kB mlocked:0kB kernel_stack:4704kB pagetables:3784kB bounce:0kB free_pcp:772kB local_pcp:188kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 Node 0 DMA: 1*4kB (U) 0*8kB 0*16kB 1*32kB (U) 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15908kB Node 0 DMA32: 5*4kB (UM) 2*8kB (UM) 3*16kB (M) 4*32kB (UM) 5*64kB (UM) 2*128kB (M) 5*256kB (UM) 4*512kB (UM) 2*1024kB (UM) 3*2048kB (UM) 718*4096kB (M) = 2953236kB Node 0 Normal: 1761*4kB (UME) 528*8kB (UME) 1200*16kB (UME) 1344*32kB (UME) 1126*64kB (UME) 372*128kB (UM) 215*256kB (UME) 23*512kB (UME) 11*1024kB (UME) 4*2048kB (UM) 527*4096kB (UM) = 2438020kB Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB 12116 total pagecache pages 0 pages in swap cache Swap cache stats: add 0, delete 0, find 0/0 Free swap = 0kB Total swap = 0kB 1965979 pages RAM 0 pages HighMem/MovableOnly 324091 pages reserved Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 warn_alloc+0x19a/0x2b0 mm/page_alloc.c:3294 __vmalloc_node_range+0x4f0/0x650 mm/vmalloc.c:1775 __vmalloc_node mm/vmalloc.c:1804 [inline] __vmalloc_node_flags_caller+0x50/0x60 mm/vmalloc.c:1826 kvmalloc_node+0x82/0xd0 mm/util.c:406 kvmalloc include/linux/mm.h:541 [inline] kvmalloc_array include/linux/mm.h:557 [inline] xt_alloc_entry_offsets+0x21/0x30 net/netfilter/x_tables.c:774 translate_table+0x235/0x1610 net/ipv4/netfilter/ip_tables.c:685 do_replace net/ipv4/netfilter/ip_tables.c:1148 [inline] do_ipt_set_ctl+0x34b/0x5c0 net/ipv4/netfilter/ip_tables.c:1682 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0xa1/0xb0 net/ipv4/ip_sockglue.c:1256 raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:850 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968 SYSC_setsockopt net/socket.c:1851 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1830 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007f057468bbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452879 RDX: 0000000000000040 RSI: 0000000000000000 RDI: 000000000000001e RBP: 000000000000038f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020002000 R11: 0000000000000212 R12: 00000000006f2608 R13: 00000000ffffffff R14: 00007f057468c6d4 R15: 0000000000000016 sctp: [Deprecated]: syz-executor5 (pid 11752) Use of int in maxseg socket option. Use struct sctp_assoc_value instead SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=11739 comm=syz-executor1 device gre0 entered promiscuous mode sctp: [Deprecated]: syz-executor5 (pid 11781) Use of int in maxseg socket option. Use struct sctp_assoc_value instead tmpfs: No value for mount option '‹¶K"WöËO¢©S£d€Yl®' dccp_v4_rcv: dropped packet with invalid checksum dccp_v4_rcv: dropped packet with invalid checksum semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant. The task syz-executor2 (11910) triggered the difference, watch for misbehavior. netlink: 5 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor3'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=12023 comm=syz-executor2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=12023 comm=syz-executor2 handle_userfault: 94 callbacks suppressed FAULT_FLAG_ALLOW_RETRY missing 30 FAULT_FLAG_ALLOW_RETRY missing 30 CPU: 0 PID: 12135 Comm: syz-executor4 Not tainted 4.14.0-next-20171124+ #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 handle_userfault+0x12fa/0x24c0 fs/userfaultfd.c:427 do_anonymous_page mm/memory.c:3109 [inline] handle_pte_fault mm/memory.c:3922 [inline] __handle_mm_fault+0x3402/0x3dd0 mm/memory.c:4048 handle_mm_fault+0x38f/0x930 mm/memory.c:4085 __do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1429 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1504 page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1088 RIP: 0010:fault_in_pages_readable include/linux/pagemap.h:601 [inline] RIP: 0010:iov_iter_fault_in_readable+0x1a7/0x410 lib/iov_iter.c:421 RSP: 0018:ffff8801cb31f928 EFLAGS: 00010246 RAX: 0000000000010000 RBX: 0000000020011fd2 RCX: ffffffff8250c7e1 RDX: 00000000000000fc RSI: ffffc90003d81000 RDI: ffff8801cb31fd28 RBP: ffff8801cb31fa08 R08: 0000000000000001 R09: 1ffff10039663edf R10: ffff8801c2f9e280 R11: ffff8801c2f9e280 R12: 1ffff10039663f28 R13: ffff8801cb31f9e0 R14: 0000000000000000 R15: ffff8801cb31fd20 generic_perform_write+0x200/0x600 mm/filemap.c:3128 __generic_file_write_iter+0x366/0x5b0 mm/filemap.c:3263 generic_file_write_iter+0x399/0x7a0 mm/filemap.c:3291 call_write_iter include/linux/fs.h:1772 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x68a/0x970 fs/read_write.c:482 vfs_write+0x18f/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007f05746acbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000030 RSI: 0000000020011fd2 RDI: 0000000000000014 RBP: 0000000000000425 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f3418 R13: 00000000ffffffff R14: 00007f05746ad6d4 R15: 0000000000000000 CPU: 0 PID: 12155 Comm: syz-executor4 Not tainted 4.14.0-next-20171124+ #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 handle_userfault+0x12fa/0x24c0 fs/userfaultfd.c:427