====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc3+ #218 Not tainted ------------------------------------------------------ syz-executor4/8160 is trying to acquire lock: (&sb->s_type->i_mutex_key#10){++++}, at: [<00000000ecc4a4ea>] inode_lock include/linux/fs.h:713 [inline] (&sb->s_type->i_mutex_key#10){++++}, at: [<00000000ecc4a4ea>] generic_file_write_iter+0xdc/0x7a0 mm/filemap.c:3289 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [<000000008de76c43>] pipe_lock_nested fs/pipe.c:67 [inline] (&pipe->mutex/1){+.+.}, at: [<000000008de76c43>] pipe_lock fs/pipe.c:75 [inline] (&pipe->mutex/1){+.+.}, at: [<000000008de76c43>] pipe_wait+0x1e6/0x280 fs/pipe.c:123 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&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 -> #5 (sb_writers){.+.+}: fs_reclaim_acquire+0x14/0x20 mm/page_alloc.c:3592 slab_pre_alloc_hook mm/slab.h:416 [inline] slab_alloc mm/slab.c:3371 [inline] kmem_cache_alloc+0x29/0x760 mm/slab.c:3545 getname_kernel+0x54/0x340 fs/namei.c:218 kern_path_create+0x23/0x40 fs/namei.c:3666 handle_create+0xc0/0x760 drivers/base/devtmpfs.c:203 -> #4 ((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 msr_device_create+0x26/0x40 arch/x86/kernel/msr.c:188 cpuhp_invoke_callback+0x2ea/0x1d20 kernel/cpu.c:182 cpuhp_thread_fun+0x48e/0x7e0 kernel/cpu.c:571 smpboot_thread_fn+0x450/0x7c0 kernel/smpboot.c:164 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441 -> #3 (cpuhp_state-up){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 cpuhp_lock_acquire kernel/cpu.c:85 [inline] cpuhp_invoke_ap_callback kernel/cpu.c:605 [inline] cpuhp_issue_call+0x1e5/0x520 kernel/cpu.c:1495 __cpuhp_setup_state_cpuslocked+0x282/0x600 kernel/cpu.c:1642 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671 cpuhp_setup_state include/linux/cpuhotplug.h:201 [inline] page_writeback_init+0x4d/0x71 mm/page-writeback.c:2081 pagecache_init+0x48/0x4f mm/filemap.c:977 start_kernel+0x6bc/0x74f init/main.c:695 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #2 (cpuhp_state_mutex){+.+.}: 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 __cpuhp_setup_state_cpuslocked+0x5b/0x600 kernel/cpu.c:1617 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671 cpuhp_setup_state_nocalls include/linux/cpuhotplug.h:229 [inline] kvm_guest_init+0x1f3/0x20f arch/x86/kernel/kvm.c:528 setup_arch+0x17e8/0x1a02 arch/x86/kernel/setup.c:1266 start_kernel+0xa5/0x74f init/main.c:530 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #1 (cpu_hotplug_lock.rw_sem){++++}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:293 get_online_cpus include/linux/cpu.h:117 [inline] lru_add_drain_all+0xe/0x20 mm/swap.c:729 shmem_wait_for_pins mm/shmem.c:2672 [inline] shmem_add_seals+0x3df/0x1060 mm/shmem.c:2780 shmem_fcntl+0xfe/0x130 mm/shmem.c:2815 do_fcntl+0x73e/0x1160 fs/fcntl.c:421 SYSC_fcntl fs/fcntl.c:463 [inline] SyS_fcntl+0xdc/0x120 fs/fcntl.c:448 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #0 (&sb->s_type->i_mutex_key#10){++++}: 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 down_write+0x87/0x120 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:713 [inline] generic_file_write_iter+0xdc/0x7a0 mm/filemap.c:3289 call_write_iter include/linux/fs.h:1772 [inline] do_iter_readv_writev+0x531/0x7f0 fs/read_write.c:653 do_iter_write+0x15a/0x540 fs/read_write.c:932 vfs_iter_write+0x77/0xb0 fs/read_write.c:945 iter_file_splice_write+0x7db/0xf30 fs/splice.c:749 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: &sb->s_type->i_mutex_key#10 --> sb_writers --> &pipe->mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex/1); lock(sb_writers); lock(&pipe->mutex/1); lock(&sb->s_type->i_mutex_key#10); *** DEADLOCK *** 2 locks held by syz-executor4/8160: #0: (sb_writers#6){.+.+}, at: [<00000000ea3b0452>] file_start_write include/linux/fs.h:2715 [inline] #0: (sb_writers#6){.+.+}, at: [<00000000ea3b0452>] do_splice fs/splice.c:1146 [inline] #0: (sb_writers#6){.+.+}, at: [<00000000ea3b0452>] SYSC_splice fs/splice.c:1402 [inline] #0: (sb_writers#6){.+.+}, at: [<00000000ea3b0452>] SyS_splice+0x1117/0x1630 fs/splice.c:1382 #1: (&pipe->mutex/1){+.+.}, at: [<000000008de76c43>] pipe_lock_nested fs/pipe.c:67 [inline] #1: (&pipe->mutex/1){+.+.}, at: [<000000008de76c43>] pipe_lock fs/pipe.c:75 [inline] #1: (&pipe->mutex/1){+.+.}, at: [<000000008de76c43>] pipe_wait+0x1e6/0x280 fs/pipe.c:123 stack backtrace: CPU: 0 PID: 8160 Comm: syz-executor4 Not tainted 4.15.0-rc3+ #218 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 down_write+0x87/0x120 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:713 [inline] generic_file_write_iter+0xdc/0x7a0 mm/filemap.c:3289 call_write_iter include/linux/fs.h:1772 [inline] do_iter_readv_writev+0x531/0x7f0 fs/read_write.c:653 do_iter_write+0x15a/0x540 fs/read_write.c:932 vfs_iter_write+0x77/0xb0 fs/read_write.c:945 iter_file_splice_write+0x7db/0xf30 fs/splice.c:749 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: 0033:0x452a39 RSP: 002b:00007fcceb58ec58 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39 RDX: 0000000000000016 RSI: 0000000000000000 RDI: 0000000000000017 RBP: 000000000000005a R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ee910 R13: 00000000ffffffff R14: 00007fcceb58f6d4 R15: 0000000000000000 nla_parse: 4 callbacks suppressed netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 17 bytes leftover after parsing attributes in process `syz-executor7'. sock: process `syz-executor4' is using obsolete setsockopt SO_BSDCOMPAT netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 17 bytes leftover after parsing attributes in process `syz-executor7'. sg_write: data in/out 845460194/1 bytes for SCSI command 0xe7-- guessing data in; program syz-executor1 not setting count and/or reply_len properly binder: 8234:8236 got reply transaction with no transaction stack binder: 8234:8236 transaction failed 29201/-71, size 32-8 line 2690 binder: 8234:8247 BC_DEAD_BINDER_DONE 0000000000000002 not found binder: 8247 RLIMIT_NICE not set binder: 8234:8247 ioctl c0306201 2000a000 returned -11 binder: 8234:8247 BC_ACQUIRE_DONE u0000000000000000 node 35 cookie mismatch 0000000000000003 != 0000000000000000 binder: 8234:8247 DecRefs 0 refcount change on invalid ref 0 ret -22 binder: 8234:8276 got reply transaction with no transaction stack binder: 8234:8276 transaction failed 29201/-71, size 32-8 line 2690 binder: BINDER_SET_CONTEXT_MGR already set binder: 8234:8276 ioctl 40046207 0 returned -16 binder: 8234:8276 BC_DEAD_BINDER_DONE 0000000000000002 not found binder: 8276 RLIMIT_NICE not set binder_alloc: 8234: binder_alloc_buf, no vma binder: 8234:8281 transaction failed 29189/-3, size 0-0 line 2890 binder: 8234:8290 BC_ACQUIRE_DONE u0000000000000000 no match device gre0 entered promiscuous mode binder: release 8234:8247 transaction 36 out, still active binder: send failed reply for transaction 36, target dead netlink: 8 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor3'. binder: 8518:8519 ioctl 40046205 fffffffffffffffe returned -22 binder_alloc: 8518: binder_alloc_buf, no vma binder: 8518:8519 transaction failed 29189/-3, size 64-48 line 2890 binder: BINDER_SET_CONTEXT_MGR already set binder: 8518:8519 ioctl 40046205 fffffffffffffffe returned -22 binder_alloc: 8518: binder_alloc_buf, no vma binder: 8518:8519 transaction failed 29189/-3, size 64-48 line 2890 binder: 8518:8537 ioctl 40046207 0 returned -16 audit: type=1400 audit(1513108317.968:619): avc: denied { create } for pid=8562 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_connector_socket permissive=1 netlink: 25 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 25 bytes leftover after parsing attributes in process `syz-executor2'. Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable Empty option to dns_resolver key Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable audit: type=1400 audit(1513108318.930:620): avc: denied { transfer } for pid=8720 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=binder permissive=1 binder: BINDER_SET_CONTEXT_MGR already set binder: 8720:8738 ioctl 40046207 0 returned -16 binder_alloc: 8720: binder_alloc_buf, no vma binder: 8720:8727 transaction failed 29189/-3, size 64-16 line 2890 binder: undelivered TRANSACTION_ERROR: 29189 binder: unexpected work type, 4, not freed binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 43, process died. audit: type=1400 audit(1513108318.993:621): avc: denied { prog_load } for pid=8729 comm="syz-executor0" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 audit: type=1400 audit(1513108319.023:622): avc: denied { map_create } for pid=8743 comm="syz-executor7" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 rfkill: input handler disabled loop: Write error at byte offset 0, length 512. print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, lost async page write sctp: [Deprecated]: syz-executor7 (pid 8865) Use of int in maxseg socket option. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor7 (pid 8865) Use of int in maxseg socket option. Use struct sctp_assoc_value instead rfkill: input handler enabled QAT: Invalid ioctl loop: Write error at byte offset 0, length 512. print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, lost async page write audit: type=1400 audit(1513108319.637:623): avc: denied { map_read map_write } for pid=8887 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 sg_write: data in/out 45116/228 bytes for SCSI command 0x0-- guessing data in; program syz-executor4 not setting count and/or reply_len properly QAT: failed to copy from user cfg_data. audit: type=1400 audit(1513108319.760:624): avc: denied { prog_run } for pid=8914 comm="syz-executor0" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 futex_wake_op: syz-executor6 tries to shift op by -1; fix this program QAT: Invalid ioctl sg_write: data in/out 45116/228 bytes for SCSI command 0x0-- guessing data in; program syz-executor4 not setting count and/or reply_len properly futex_wake_op: syz-executor6 tries to shift op by -1; fix this program QAT: failed to copy from user cfg_data. QAT: Invalid ioctl sg_write: data in/out 45116/228 bytes for SCSI command 0x0-- guessing data in; program syz-executor4 not setting count and/or reply_len properly QAT: failed to copy from user cfg_data. QAT: Invalid ioctl sg_write: data in/out 45116/228 bytes for SCSI command 0x0-- guessing data in; program syz-executor4 not setting count and/or reply_len properly QAT: failed to copy from user cfg_data. binder: 9052:9055 ERROR: BC_REGISTER_LOOPER called without request binder: 9055 RLIMIT_NICE not set binder: 9052:9055 got reply transaction with no transaction stack binder: 9052:9055 transaction failed 29201/-71, size 24-8 line 2690 binder: BINDER_SET_CONTEXT_MGR already set binder: 9052:9064 ERROR: BC_REGISTER_LOOPER called without request binder: 9064 RLIMIT_NICE not set binder: 9052:9075 got reply transaction with no transaction stack binder: 9052:9075 transaction failed 29201/-71, size 24-8 line 2690 binder: 9052:9055 ioctl 40046207 0 returned -16 binder_alloc: 9052: binder_alloc_buf, no vma binder: 9052:9064 transaction failed 29189/-3, size 0-0 line 2890 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201 binder: release 9052:9064 transaction 49 out, still active binder: undelivered TRANSACTION_COMPLETE binder: send failed reply for transaction 49, target dead print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, lost async page write audit: type=1400 audit(1513108320.766:625): avc: denied { map } for pid=9085 comm="syz-executor6" path="/dev/ptmx" dev="devtmpfs" ino=80 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:ptmx_t:s0 tclass=chr_file permissive=1 QAT: Invalid ioctl device gre0 entered promiscuous mode device gre0 entered promiscuous mode nla_parse: 5 callbacks suppressed netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. device eql entered promiscuous mode SELinux: unrecognized netlink message: protocol=9 nlmsg_type=44760 sclass=netlink_audit_socket pig=9284 comm=syz-executor1 SELinux: unrecognized netlink message: protocol=9 nlmsg_type=44760 sclass=netlink_audit_socket pig=9306 comm=syz-executor1 netlink: 37 bytes leftover after parsing attributes in process `syz-executor1'. kvm: pic: non byte read netlink: 37 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 'syz-executor2': attribute type 10 has an invalid length. binder_alloc: binder_alloc_mmap_handler: 9440 20000000-20002000 already mapped failed -16 binder: BINDER_SET_CONTEXT_MGR already set binder: 9440:9447 ioctl 40046207 0 returned -16 binder_alloc: 9440: binder_alloc_buf, no vma binder: 9440:9461 transaction failed 29189/-3, size 64-16 line 2890 binder: unexpected work type, 4, not freed binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered transaction 54, process died. QAT: Invalid ioctl device lo left promiscuous mode QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant. The task syz-executor2 (9570) triggered the difference, watch for misbehavior. audit: type=1326 audit(1513108323.356:626): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=9601 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000 audit: type=1326 audit(1513108323.356:627): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=9601 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000 audit: type=1326 audit(1513108323.383:628): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=9601 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=283 compat=0 ip=0x452a39 code=0x7ffc0000 audit: type=1326 audit(1513108323.383:629): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=9601 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000 audit: type=1326 audit(1513108323.383:630): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=9601 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000