Hello, syzbot found the following issue on: HEAD commit: 61c3426aca2c Add linux-next specific files for 20221102 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=14473561880000 kernel config: https://syzkaller.appspot.com/x/.config?x=acb529cc910d907c dashboard link: https://syzkaller.appspot.com/bug?extid=746a4eece09f86bc39d7 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109e96a6880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15d036de880000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/cc56d88dd6a3/disk-61c3426a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/5921b65b080f/vmlinux-61c3426a.xz kernel image: https://storage.googleapis.com/syzbot-assets/39cbd355fedd/bzImage-61c3426a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+746a4eece09f86bc39d7@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] CPU: 0 PID: 5234 Comm: syz-executor931 Not tainted 6.1.0-rc3-next-20221102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:__elevator_get block/elevator.h:94 [inline] RIP: 0010:blk_mq_elv_switch_none block/blk-mq.c:4593 [inline] RIP: 0010:__blk_mq_update_nr_hw_queues block/blk-mq.c:4658 [inline] RIP: 0010:blk_mq_update_nr_hw_queues+0x304/0xe40 block/blk-mq.c:4709 Code: 8d 47 18 49 89 6f 10 4c 89 c0 48 c1 e8 03 80 3c 18 00 0f 85 f7 09 00 00 49 8b 47 18 48 8d b8 e8 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 12 09 00 00 48 8b b8 e8 00 00 00 4c 89 44 24 08 RSP: 0018:ffffc90003cdfc08 EFLAGS: 00010206 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 000000000000001d RSI: 0000000000000002 RDI: 00000000000000e8 RBP: ffff88801dbd0000 R08: ffff888027c89398 R09: ffffffff8de2e517 R10: fffffbfff1bc5ca2 R11: 0000000000000000 R12: ffffc90003cdfc70 R13: ffff88801dbd0008 R14: ffff88801dbd03f8 R15: ffff888027c89380 FS: 0000555557259300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005d84c8 CR3: 000000007a7cb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> nbd_start_device+0x153/0xc30 drivers/block/nbd.c:1355 nbd_start_device_ioctl drivers/block/nbd.c:1405 [inline] __nbd_ioctl drivers/block/nbd.c:1481 [inline] nbd_ioctl+0x5a1/0xbd0 drivers/block/nbd.c:1521 blkdev_ioctl+0x36e/0x800 block/ioctl.c:614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f41f05946b9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff1b23e808 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f41f05946b9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 00007f41f05541c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f41f0554250 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__elevator_get block/elevator.h:94 [inline] RIP: 0010:blk_mq_elv_switch_none block/blk-mq.c:4593 [inline] RIP: 0010:__blk_mq_update_nr_hw_queues block/blk-mq.c:4658 [inline] RIP: 0010:blk_mq_update_nr_hw_queues+0x304/0xe40 block/blk-mq.c:4709 Code: 8d 47 18 49 89 6f 10 4c 89 c0 48 c1 e8 03 80 3c 18 00 0f 85 f7 09 00 00 49 8b 47 18 48 8d b8 e8 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 1a 00 0f 85 12 09 00 00 48 8b b8 e8 00 00 00 4c 89 44 24 08 RSP: 0018:ffffc90003cdfc08 EFLAGS: 00010206 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 000000000000001d RSI: 0000000000000002 RDI: 00000000000000e8 RBP: ffff88801dbd0000 R08: ffff888027c89398 R09: ffffffff8de2e517 R10: fffffbfff1bc5ca2 R11: 0000000000000000 R12: ffffc90003cdfc70 R13: ffff88801dbd0008 R14: ffff88801dbd03f8 R15: ffff888027c89380 FS: 0000555557259300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005d84c8 CR3: 000000007a7cb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 8d 47 18 lea 0x18(%rdi),%eax 3: 49 89 6f 10 mov %rbp,0x10(%r15) 7: 4c 89 c0 mov %r8,%rax a: 48 c1 e8 03 shr $0x3,%rax e: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 12: 0f 85 f7 09 00 00 jne 0xa0f 18: 49 8b 47 18 mov 0x18(%r15),%rax 1c: 48 8d b8 e8 00 00 00 lea 0xe8(%rax),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 1a 00 cmpb $0x0,(%rdx,%rbx,1) <-- trapping instruction 2e: 0f 85 12 09 00 00 jne 0x946 34: 48 8b b8 e8 00 00 00 mov 0xe8(%rax),%rdi 3b: 4c 89 44 24 08 mov %r8,0x8(%rsp) --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
