============================================ WARNING: possible recursive locking detected 4.15.0-rc8+ #269 Not tainted -------------------------------------------- syz-executor2/8802 is trying to acquire lock: (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_chr_write_iter+0x278/0x1580 drivers/vhost/vhost.c:1046 but task is already holding lock: (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_chr_write_iter+0x278/0x1580 drivers/vhost/vhost.c:1046 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&vq->mutex); lock(&vq->mutex); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz-executor2/8802: #0: (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] #0: (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] #0: (&vq->mutex){+.+.}, at: [<000000000f9bc9a9>] vhost_chr_write_iter+0x278/0x1580 drivers/vhost/vhost.c:1046 stack backtrace: CPU: 0 PID: 8802 Comm: syz-executor2 Not tainted 4.15.0-rc8+ #269 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_deadlock_bug kernel/locking/lockdep.c:1756 [inline] check_deadlock kernel/locking/lockdep.c:1800 [inline] validate_chain kernel/locking/lockdep.c:2396 [inline] __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3426 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __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 vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] vhost_chr_write_iter+0x278/0x1580 drivers/vhost/vhost.c:1046 vhost_net_chr_write_iter+0x59/0x70 drivers/vhost/net.c:1353 call_write_iter include/linux/fs.h:1772 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 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+0x29/0xa0 RIP: 0033:0x452ee9 RSP: 002b:00007f9109575c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ee9 RDX: 0000000000000068 RSI: 00000000202ff000 RDI: 0000000000000013 RBP: 00000000000003d6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4cb0 R13: 00000000ffffffff R14: 00007f91095766d4 R15: 0000000000000000 QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl binder: 8907:8909 ERROR: BC_REGISTER_LOOPER called without request binder: 8909 RLIMIT_NICE not set binder: 8909 RLIMIT_NICE not set binder: 8907:8916 got reply transaction with bad transaction stack, transaction 35 has target 8907:8909 binder: 8907:8916 transaction failed 29201/-71, size 24-8 line 2718 binder: BINDER_SET_CONTEXT_MGR already set binder: 8907:8916 ioctl 40046207 0 returned -16 binder: 8907:8909 ERROR: BC_REGISTER_LOOPER called without request binder: 8909 RLIMIT_NICE not set binder_alloc: 8907: binder_alloc_buf, no vma binder: 8907:8916 transaction failed 29189/-3, size 0-0 line 2903 binder: undelivered TRANSACTION_ERROR: 29189 binder: release 8907:8909 transaction 35 in, still active binder: send failed reply for transaction 35 to 8907:8916 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29201 binder: undelivered TRANSACTION_ERROR: 29189 irq bypass consumer (token 000000009a1e1459) registration fails: -16 rpcbind: RPC call returned error 22 kauditd_printk_skb: 83 callbacks suppressed audit: type=1326 audit(1516426043.342:451): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.343:452): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=2 compat=0 ip=0x40d1e1 code=0x7ffc0000 audit: type=1326 audit(1516426043.344:453): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.344:454): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.345:455): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=16 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.345:456): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.345:457): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=123 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.345:458): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.346:459): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=55 compat=0 ip=0x452ee9 code=0x7ffc0000 audit: type=1326 audit(1516426043.347:460): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=8997 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452ee9 code=0x7ffc0000 rpcbind: RPC call returned error 22 dccp_invalid_packet: P.type (REQUEST) not Data || [Data]Ack, while P.X == 0 binder_alloc: 9274: binder_alloc_buf failed to map page at 20000000 in userspace binder: 9274:9279 transaction failed 29201/-12, size 0-0 line 2903 binder: BINDER_SET_CONTEXT_MGR already set binder: 9274:9289 ioctl 40046207 0 returned -16 binder_alloc: 9274: binder_alloc_buf, no vma binder: 9274:9289 transaction failed 29189/-3, size 0-0 line 2903 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201 semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant. The task syz-executor4 (9343) triggered the difference, watch for misbehavior. sctp: [Deprecated]: syz-executor4 (pid 9364) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor4 (pid 9364) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead 9pnet_virtio: no channels available for device ./file0 9pnet_virtio: no channels available for device ./file0 binder: 9525 RLIMIT_NICE not set binder: BINDER_SET_CONTEXT_MGR already set binder: 9519:9540 ioctl 40046207 0 returned -16 binder_alloc: 9519: binder_alloc_buf, no vma binder: 9519:9540 transaction failed 29189/-3, size 0-0 line 2903 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_COMPLETE binder: 9597:9605 got transaction with invalid parent offset or type binder: 9597:9605 transaction failed 29201/-22, size 40-8 line 3088 binder_alloc: binder_alloc_mmap_handler: 9597 20000000-20002000 already mapped failed -16 binder: BINDER_SET_CONTEXT_MGR already set binder: 9597:9616 ioctl 40046207 0 returned -16 binder_alloc: 9597: binder_alloc_buf, no vma binder: 9597:9632 transaction failed 29189/-3, size 40-8 line 2903 dccp_v6_rcv: dropped packet with invalid checksum binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201