RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a429 RDX: 0000000000000002 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 00000000006dbc20 R08: 0000000000000001 R09: 0000000000000032 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c R13: 00007f2a2bb33d80 R14: ffffffffffffffff R15: 0000000000000005 BUG: unable to handle kernel NULL pointer dereference at 0000000000000118 PGD 1cdc72067 P4D 1cdc72067 PUD 1cdeb4067 PMD 0 Oops: 0002 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5498 Comm: syz-executor702 Not tainted 4.19.0-rc5+ #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:cpumask_set_cpu include/linux/cpumask.h:311 [inline] RIP: 0010:blk_mq_map_swqueue+0x29c/0xa70 block/blk-mq.c:2336 Code: 80 3c 1a 00 0f 85 fa 06 00 00 44 89 ee bf 3f 00 00 00 4d 8b 24 24 e8 33 01 03 fe 41 83 fd 3f 0f 87 1c 05 00 00 e8 14 00 03 fe 4d 0f ab b4 24 18 01 00 00 49 8d bc 24 74 01 00 00 48 89 fa 48 RSP: 0018:ffff8801cedaf4e0 EFLAGS: 00010293 RAX: ffff8801c4f80400 RBX: dffffc0000000000 RCX: ffffffff837be3fd RDX: 0000000000000000 RSI: ffffffff837be40c RDI: 0000000000000005 RBP: ffff8801cedaf550 R08: ffff8801c4f80400 R09: 0000000000000000 R10: ffffed003a31dff0 R11: ffff8801d18eff83 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: ffff8801d1fd7000 FS: 00007f2a2bb34700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000118 CR3: 00000001c55c5000 CR4: 00000000001406f0 Call Trace: blk_mq_queue_reinit block/blk-mq.c:2675 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:2994 [inline] blk_mq_update_nr_hw_queues+0xb2a/0xe50 block/blk-mq.c:3008 nbd_start_device+0x1d2/0xcd0 drivers/block/nbd.c:1154 nbd_start_device_ioctl drivers/block/nbd.c:1195 [inline] __nbd_ioctl drivers/block/nbd.c:1266 [inline] nbd_ioctl+0x6af/0xd40 drivers/block/nbd.c:1306 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x9ac/0x2010 block/ioctl.c:601 block_ioctl+0xee/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x44a429 Code: e8 ac b4 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2a2bb33d78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 000000000044a429 RDX: 0000000000000002 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 00000000006dbc20 R08: 0000000000000001 R09: 0000000000000032 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c R13: 00007f2a2bb33d80 R14: ffffffffffffffff R15: 0000000000000005 Modules linked in: CR2: 0000000000000118 ---[ end trace cca4d386a05f3868 ]--- RIP: 0010:cpumask_set_cpu include/linux/cpumask.h:311 [inline] RIP: 0010:blk_mq_map_swqueue+0x29c/0xa70 block/blk-mq.c:2336 Code: 80 3c 1a 00 0f 85 fa 06 00 00 44 89 ee bf 3f 00 00 00 4d 8b 24 24 e8 33 01 03 fe 41 83 fd 3f 0f 87 1c 05 00 00 e8 14 00 03 fe 4d 0f ab b4 24 18 01 00 00 49 8d bc 24 74 01 00 00 48 89 fa 48 RSP: 0018:ffff8801cedaf4e0 EFLAGS: 00010293 RAX: ffff8801c4f80400 RBX: dffffc0000000000 RCX: ffffffff837be3fd RDX: 0000000000000000 RSI: ffffffff837be40c RDI: 0000000000000005 RBP: ffff8801cedaf550 R08: ffff8801c4f80400 R09: 0000000000000000 R10: ffffed003a31dff0 R11: ffff8801d18eff83 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: ffff8801d1fd7000 FS: 00007f2a2bb34700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000118 CR3: 00000001c55c5000 CR4: 00000000001406f0