====================================================== WARNING: possible circular locking dependency detected 4.13.0-mm1+ #7 Not tainted ------------------------------------------------------ loop0/3607 is trying to acquire lock: (&sb->s_type->i_mutex_key#9){++++}, at: [] inode_lock include/linux/fs.h:712 [inline] (&sb->s_type->i_mutex_key#9){++++}, at: [] shmem_fallocate+0x161/0x1180 mm/shmem.c:2841 but now in release context of a crosslock acquired at the following: ((complete)&ret.event){+.+.}, at: [] submit_bio_wait+0x15e/0x200 block/bio.c:953 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 ((complete)&ret.event){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 complete_acquire include/linux/completion.h:39 [inline] __wait_for_common kernel/sched/completion.c:108 [inline] wait_for_common_io kernel/sched/completion.c:128 [inline] wait_for_completion_io+0xc8/0x770 kernel/sched/completion.c:176 submit_bio_wait+0x15e/0x200 block/bio.c:953 blkdev_issue_zeroout+0x13c/0x1d0 block/blk-lib.c:370 sb_issue_zeroout include/linux/blkdev.h:1367 [inline] ext4_init_inode_table+0x4fd/0xdb1 fs/ext4/ialloc.c:1447 ext4_run_li_request fs/ext4/super.c:2866 [inline] ext4_lazyinit_thread+0x81a/0xd40 fs/ext4/super.c:2960 kthread+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 -> #3 (&meta_group_info[i]->alloc_sem){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 down_read+0x96/0x150 kernel/locking/rwsem.c:23 __ext4_new_inode+0x26dc/0x4f00 fs/ext4/ialloc.c:1056 ext4_symlink+0x2d9/0xae0 fs/ext4/namei.c:3118 vfs_symlink+0x323/0x560 fs/namei.c:4115 SYSC_symlinkat fs/namei.c:4142 [inline] SyS_symlinkat fs/namei.c:4122 [inline] SYSC_symlink fs/namei.c:4155 [inline] SyS_symlink+0x134/0x200 fs/namei.c:4153 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #2 (jbd2_handle){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 start_this_handle+0x4b8/0x1080 fs/jbd2/transaction.c:390 jbd2__journal_start+0x389/0x9f0 fs/jbd2/transaction.c:444 __ext4_journal_start_sb+0x15f/0x550 fs/ext4/ext4_jbd2.c:80 __ext4_journal_start fs/ext4/ext4_jbd2.h:314 [inline] ext4_dirty_inode+0x56/0xa0 fs/ext4/inode.c:5859 __mark_inode_dirty+0x912/0x1170 fs/fs-writeback.c:2096 generic_update_time+0x1b2/0x270 fs/inode.c:1649 update_time fs/inode.c:1665 [inline] touch_atime+0x26d/0x2f0 fs/inode.c:1737 file_accessed include/linux/fs.h:2061 [inline] ext4_file_mmap+0x161/0x1b0 fs/ext4/file.c:352 call_mmap include/linux/fs.h:1775 [inline] mmap_region+0xa99/0x15a0 mm/mmap.c:1690 do_mmap+0x6a1/0xd50 mm/mmap.c:1468 do_mmap_pgoff include/linux/mm.h:2151 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1518 [inline] SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1476 SYSC_mmap arch/x86/kernel/sys_x86_64.c:99 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:90 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #1 (&mm->mmap_sem){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __might_fault+0x13a/0x1d0 mm/memory.c:4502 _copy_to_user+0x2c/0xc0 lib/usercopy.c:24 copy_to_user include/linux/uaccess.h:154 [inline] filldir+0x1a7/0x320 fs/readdir.c:196 dir_emit_dot include/linux/fs.h:3341 [inline] dir_emit_dots include/linux/fs.h:3352 [inline] dcache_readdir+0x12d/0x5e0 fs/libfs.c:193 iterate_dir+0x4b2/0x5d0 fs/readdir.c:51 SYSC_getdents fs/readdir.c:231 [inline] SyS_getdents+0x225/0x450 fs/readdir.c:212 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #0 (&sb->s_type->i_mutex_key#9){++++}: down_write+0x87/0x120 kernel/locking/rwsem.c:53 inode_lock include/linux/fs.h:712 [inline] shmem_fallocate+0x161/0x1180 mm/shmem.c:2841 lo_discard drivers/block/loop.c:434 [inline] do_req_filebacked drivers/block/loop.c:570 [inline] loop_handle_cmd drivers/block/loop.c:1705 [inline] loop_queue_work+0x46f/0x3900 drivers/block/loop.c:1719 kthread_worker_fn+0x340/0x9b0 kernel/kthread.c:635 loop_kthread_worker_fn+0x51/0x60 drivers/block/loop.c:836 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#9 --> &meta_group_info[i]->alloc_sem --> (complete)&ret.event Possible unsafe locking scenario by crosslock: CPU0 CPU1 ---- ---- lock(&meta_group_info[i]->alloc_sem); lock((complete)&ret.event); lock(&sb->s_type->i_mutex_key#9); unlock((complete)&ret.event); *** DEADLOCK *** 1 lock held by loop0/3607: #0: (&x->wait#14){..-.}, at: [] complete+0x18/0x80 kernel/sched/completion.c:34 stack backtrace: CPU: 1 PID: 3607 Comm: loop0 Not tainted 4.13.0-mm1+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_circular_bug+0x503/0x710 kernel/locking/lockdep.c:1259 check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 commit_xhlock kernel/locking/lockdep.c:5015 [inline] commit_xhlocks kernel/locking/lockdep.c:5059 [inline] lock_commit_crosslock+0xe73/0x1d10 kernel/locking/lockdep.c:5098 complete_release_commit include/linux/completion.h:49 [inline] complete+0x24/0x80 kernel/sched/completion.c:39 submit_bio_wait_endio+0x9c/0xd0 block/bio.c:930 bio_endio+0x2f8/0x8d0 block/bio.c:1843 req_bio_endio block/blk-core.c:204 [inline] blk_update_request+0x2a6/0xe20 block/blk-core.c:2743 blk_mq_end_request+0x54/0x120 block/blk-mq.c:509 lo_complete_rq+0xbe/0x1f0 drivers/block/loop.c:463 __blk_mq_complete_request+0x38f/0x6c0 block/blk-mq.c:550 blk_mq_complete_request+0x4f/0x60 block/blk-mq.c:570 loop_handle_cmd drivers/block/loop.c:1710 [inline] loop_queue_work+0x26b/0x3900 drivers/block/loop.c:1719 kthread_worker_fn+0x340/0x9b0 kernel/kthread.c:635 loop_kthread_worker_fn+0x51/0x60 drivers/block/loop.c:836 kthread+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 audit: type=1326 audit(1505959765.130:303): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=7431 comm="syz-executor5" exe="/root/syz-executor5" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 device lo entered promiscuous mode audit: type=1326 audit(1505959765.211:304): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=7431 comm="syz-executor5" exe="/root/syz-executor5" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 mmap: syz-executor5 (7478): VmData 13553664 exceed data ulimit 0. Update limits or use boot option ignore_rlimit_data. sctp: [Deprecated]: syz-executor4 (pid 7510) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor4 (pid 7547) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor1 (pid 7633) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor1 (pid 7647) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead nla_parse: 15 callbacks suppressed netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. QAT: Invalid ioctl QAT: Invalid ioctl audit: type=1326 audit(1505959767.029:305): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=7868 comm="syz-executor1" exe="/root/syz-executor1" sig=9 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0x0 netlink: 1 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor7'. device gre0 entered promiscuous mode SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=8114 comm=syz-executor6 sit0: Invalid MTU 2147483645 requested, hw max 65508 sctp: [Deprecated]: syz-executor4 (pid 8206) Use of int in maxseg socket option. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor4 (pid 8210) Use of int in maxseg socket option. Use struct sctp_assoc_value instead sit0: Invalid MTU 2147483645 requested, hw max 65508 netlink: 1 bytes leftover after parsing attributes in process `syz-executor1'. IPv6: NLM_F_REPLACE set, but no existing node found! netlink: 1 bytes leftover after parsing attributes in process `syz-executor1'. IPv6: NLM_F_REPLACE set, but no existing node found! audit: type=1326 audit(1505959768.496:306): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=8232 comm="syz-executor2" exe="/root/syz-executor2" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl kvm [8395]: vcpu2, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 kvm: apic: phys broadcast and lowest prio dccp_close: ABORT with 398 bytes unread dccp_close: ABORT with 398 bytes unread kvm [8395]: vcpu2, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 kvm: apic: phys broadcast and lowest prio netlink: 2 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor1'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=8467 comm=syz-executor0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=51 sclass=netlink_route_socket pig=8460 comm=syz-executor0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=8477 comm=syz-executor0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=51 sclass=netlink_route_socket pig=8477 comm=syz-executor0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=3001 sclass=netlink_route_socket pig=8528 comm=syz-executor2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=3001 sclass=netlink_route_socket pig=8545 comm=syz-executor2 QAT: Invalid ioctl QAT: Invalid ioctl kvm [8587]: vcpu2, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 kvm [8587]: vcpu2, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 QAT: Invalid ioctl TCP: request_sock_TCP: Possible SYN flooding on port 20024. Sending cookies. Check SNMP counters. kvm pmu: pin control bit is ignored kvm_pmu: event creation failed -2 QAT: Invalid ioctl QAT: Invalid ioctl netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. *** Guest State *** CR0: actual=0x0000000080000031, shadow=0x0000000080000011, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000006062, shadow=0x0000000000004022, gh_mask=ffffffffffffe871 CR3 = 0x0000000000002000 RSP = 0x0000000000000f80 RIP = 0x000000000000001c RFLAGS=0x00000082 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000f80 CS:RIP=0050:0000000000002810 CS: sel=0x0050, attr=0x0209b, limit=0x0000ffff, base=0x0000000000000000 DS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 SS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 ES: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 FS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 GS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 GDTR: limit=0x000007ff, base=0x0000000000001000 LDTR: sel=0x0008, attr=0x04082, limit=0x000007ff, base=0x0000000000001800 IDTR: limit=0x000001ff, base=0x0000000000003800 TR: sel=0x00d8, attr=0x0008b, limit=0x000001ff, base=0x0000000000003a00 EFER = 0x0000000000000501 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811b8bff RSP = 0xffff8801c3bf74c8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007f2584ec8700 GSBase=ffff8801db200000 TRBase=ffff8801db223100 GDTBase=ffffffffff577000 IDTBase=ffffffffff57b000 CR0=0000000080050033 CR3=00000001d3a8c000 CR4=00000000001426f0 Sysenter RSP=0000000000000000 CS:RIP=0010:ffffffff84d450b0 EFER = 0x0000000000000d01 PAT = 0x0000000000000000 *** Control State *** PinBased=0000003f CPUBased=b6986dfa SecondaryExec=0000004a EntryControls=0000d3ff ExitControls=0023efff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000000 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffffd603deb663 EPT pointer = 0x00000001cb19b01e *** Guest State *** CR0: actual=0x0000000080000031, shadow=0x0000000080000011, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000006062, shadow=0x0000000000004022, gh_mask=ffffffffffffe871 CR3 = 0x0000000000002000 RSP = 0x0000000000000f80 RIP = 0x000000000000001c RFLAGS=0x00000082 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000f80 CS:RIP=0050:0000000000002810 CS: sel=0x0050, attr=0x0209b, limit=0x0000ffff, base=0x0000000000000000 DS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 SS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 ES: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 FS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 GS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 GDTR: limit=0x000007ff, base=0x0000000000001000 LDTR: sel=0x0008, attr=0x04082, limit=0x000007ff, base=0x0000000000001800 IDTR: limit=0x000001ff, base=0x0000000000003800 TR: sel=0x00d8, attr=0x0008b, limit=0x000001ff, base=0x0000000000003a00 EFER = 0x0000000000000501 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811b8bff RSP = 0xffff8801c3bf74c8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007f2584ec8700 GSBase=ffff8801db200000 TRBase=ffff8801db223100 GDTBase=ffffffffff577000 IDTBase=ffffffffff57b000 CR0=0000000080050033 CR3=00000001d3a8c000 CR4=00000000001426f0 Sysenter RSP=0000000000000000 CS:RIP=0010:ffffffff84d450b0 EFER = 0x0000000000000d01 PAT = 0x0000000000000000 *** Control State *** PinBased=0000003f CPUBased=b6986dfa SecondaryExec=0000004a EntryControls=0000d3ff ExitControls=0023efff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000000 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffffd5d676f873 EPT pointer = 0x00000001d936701e kvm [8911]: vcpu2, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 kvm [8911]: vcpu2, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=3001 sclass=netlink_route_socket pig=9178 comm=syz-executor2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=3001 sclass=netlink_route_socket pig=9187 comm=syz-executor2 nla_parse: 3 callbacks suppressed netlink: 2 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor5'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=33381 sclass=netlink_route_socket pig=9445 comm=syz-executor4 audit: type=1326 audit(1505959773.731:307): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9437 comm="syz-executor6" exe="/root/syz-executor6" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 rfkill: input handler disabled netlink: 4 bytes leftover after parsing attributes in process `syz-executor4'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=33381 sclass=netlink_route_socket pig=9455 comm=syz-executor4 netlink: 4 bytes leftover after parsing attributes in process `syz-executor4'. audit: type=1326 audit(1505959773.845:308): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9437 comm="syz-executor6" exe="/root/syz-executor6" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 rfkill: input handler enabled