audit: type=1400 audit(1516400993.754:7): avc: denied { map } for pid=3665 comm="syzkaller519282" path="/root/syzkaller519282392" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 ============================================ WARNING: possible recursive locking detected 4.15.0-rc8+ #269 Not tainted -------------------------------------------- syzkaller519282/3665 is trying to acquire lock: (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_chr_write_iter+0x278/0x1580 drivers/vhost/vhost.c:1046 but task is already holding lock: (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] 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 syzkaller519282/3665: #0: (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_dev_lock_vqs drivers/vhost/vhost.c:907 [inline] #0: (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_process_iotlb_msg drivers/vhost/vhost.c:997 [inline] #0: (&vq->mutex){+.+.}, at: [<00000000a4d42c38>] vhost_chr_write_iter+0x278/0x1580 drivers/vhost/vhost.c:1046 stack backtrace: CPU: 1 PID: 3665 Comm: syzkaller519282 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: 0033:0x43fd79 RSP: 002b:00007ffd0276fa68 EFLAGS: 00000203 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd79 RDX: 0000000000000068 RSI: 0000000020004f98 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000203 R12: 00000000004016a0 R13: 0000000000401730 R14: 0000000000000000 R15: 0000000000000000 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 3665 Comm: syzkaller519282 Not tainted 4.15.0-rc8+ #269 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vhost_umem_interval_tree_iter_first drivers/vhost/vhost.c:52 [inline] RIP: 0010:vhost_del_umem_range drivers/vhost/vhost.c:949 [inline] RIP: 0010:vhost_process_iotlb_msg drivers/vhost/vhost.c:1019 [inline] RIP: 0010:vhost_chr_write_iter+0x5f5/0x1580 drivers/vhost/vhost.c:1046 RSP: 0018:ffff8801bc6c7b28 EFLAGS: 00010246 RAX: 0000000000000002 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8801bbf80200 RBP: ffff8801bc6c7ca8 R08: ffffffff8412f818 R09: 0000000000000000 R10: ffff8801bc6c7b18 R11: fffffbfff0fda47f R12: 0000000020005000 R13: ffff8801bbf80140 R14: ffff8801bbf84900 R15: 1ffff100378d8f70 FS: 00000000011f6880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020004f98 CR3: 00000001d9a1f004 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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: 0033:0x43fd79 RSP: 002b:00007ffd0276fa68 EFLAGS: 00000203 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd79 RDX: 0000000000000068 RSI: 0000000020004f98 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000203 R12: 00000000004016a0 R13: 0000000000401730 R14: 0000000000000000 R15: 0000000000000000 Code: e9 03 80 3c 11 00 0f 85 7d 0f 00 00 49 8b b5 c0 00 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 f1 48 89 b5 c0 fe ff ff 48 c1 e9 03 <80> 3c 11 00 0f 85 74 0b 00 00 48 8b b5 c0 fe ff ff 4c 8b 36 4d RIP: vhost_umem_interval_tree_iter_first drivers/vhost/vhost.c:52 [inline] RSP: ffff8801bc6c7b28 RIP: vhost_del_umem_range drivers/vhost/vhost.c:949 [inline] RSP: ffff8801bc6c7b28 RIP: vhost_process_iotlb_msg drivers/vhost/vhost.c:1019 [inline] RSP: ffff8801bc6c7b28 RIP: vhost_chr_write_iter+0x5f5/0x1580 drivers/vhost/vhost.c:1046 RSP: ffff8801bc6c7b28 ---[ end trace e5849ebbed84bfe3 ]---