bisecting fixing commit since 90c9e950c0def5c354b4a6154a2ddda3e5f214ac building syzkaller on a7dab6385c1d95547a88e22577fb56fbcd5c37eb testing commit 90c9e950c0def5c354b4a6154a2ddda3e5f214ac compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 5435818f75bcc452ca157c0ccdc8c892772b562ebf064724aa50957bd511fd5b run #0: crashed: general protection fault in blk_mq_free_rqs run #1: crashed: general protection fault in blk_mq_free_rqs run #2: crashed: general protection fault in blk_mq_free_rqs run #3: crashed: general protection fault in blk_mq_free_rqs run #4: crashed: WARNING in kernfs_remove_by_name_ns run #5: crashed: general protection fault in blk_mq_free_rqs run #6: crashed: general protection fault in blk_mq_free_rqs run #7: crashed: general protection fault in blk_mq_free_rqs run #8: crashed: general protection fault in blk_mq_free_rqs run #9: crashed: general protection fault in blk_mq_free_rqs run #10: crashed: general protection fault in blk_mq_free_rqs run #11: crashed: general protection fault in blk_mq_free_rqs run #12: crashed: general protection fault in blk_mq_free_rqs run #13: crashed: general protection fault in blk_mq_free_rqs run #14: crashed: general protection fault in blk_mq_free_rqs run #15: crashed: general protection fault in blk_mq_free_rqs run #16: crashed: general protection fault in blk_mq_free_rqs run #17: crashed: WARNING in kernfs_remove_by_name_ns run #18: crashed: WARNING in kernfs_remove_by_name_ns run #19: crashed: general protection fault in blk_mq_free_rqs testing current HEAD 9be9ed2612b5aedb52a2c240edb1630b6b743cb6 testing commit 9be9ed2612b5aedb52a2c240edb1630b6b743cb6 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b514923faa2b6b53179fa1d4cc3a01605ed38c201352c9743305f5cc5bc72916 run #0: crashed: general protection fault in blk_mq_free_rqs run #1: crashed: general protection fault in blk_mq_free_rqs run #2: crashed: general protection fault in blk_mq_free_rqs run #3: crashed: WARNING in kernfs_remove_by_name_ns run #4: crashed: general protection fault in blk_mq_free_rqs run #5: crashed: general protection fault in blk_mq_free_rqs run #6: crashed: general protection fault in blk_mq_free_rqs run #7: crashed: general protection fault in blk_mq_free_rqs run #8: crashed: general protection fault in blk_mq_free_rqs run #9: crashed: general protection fault in blk_mq_free_rqs revisions tested: 2, total time: 19m49.694173003s (build: 12m19.255699541s, test: 6m59.184574195s) the crash still happens on HEAD commit msg: Merge tag 'platform-drivers-x86-v5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 crash: general protection fault in blk_mq_free_rqs general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 4160 Comm: syz-executor.0 Not tainted 5.18.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:blk_mq_clear_rq_mapping block/blk-mq.c:3052 [inline] RIP: 0010:blk_mq_free_rqs+0x377/0x860 block/blk-mq.c:3100 Code: 0f 85 4c 03 00 00 48 8b 44 24 20 48 8b 48 28 83 f9 3f 0f 87 53 4c d4 04 48 8b 44 24 08 41 bc 00 10 00 00 49 d3 e4 4c 03 24 24 <0f> b6 00 4c 89 64 24 10 84 c0 74 08 3c 03 0f 8e 07 03 00 00 48 8b RSP: 0018:ffffc9000301fac0 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 000000006e550000 RCX: 0000000000000004 RDX: 1ffff110037b0212 RSI: ffff88801bd81000 RDI: ffffea0001b95428 RBP: ffff88801a6a0800 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88806e560000 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007fde6c5ae700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fde6c58d718 CR3: 0000000019d75000 CR4: 0000000000350ef0 Call Trace: blk_mq_sched_free_rqs block/blk-mq-sched.c:637 [inline] blk_mq_sched_free_rqs+0x183/0x220 block/blk-mq-sched.c:626 elevator_exit block/elevator.c:196 [inline] elevator_switch_mq+0xa7/0x4f0 block/elevator.c:600 blk_mq_elv_switch_none block/blk-mq.c:4453 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:4513 [inline] blk_mq_update_nr_hw_queues+0x38b/0xca0 block/blk-mq.c:4564 nbd_start_device+0x10a/0xb70 drivers/block/nbd.c:1347 nbd_start_device_ioctl drivers/block/nbd.c:1397 [inline] __nbd_ioctl drivers/block/nbd.c:1471 [inline] nbd_ioctl+0x3ba/0x8f0 drivers/block/nbd.c:1511 blkdev_ioctl+0x2ff/0x6c0 block/ioctl.c:588 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+0x11f/0x190 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fde6b489059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fde6c5ae168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fde6b59bf60 RCX: 00007fde6b489059 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000009 RBP: 00007fde6c5ae1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffec26e2aff R14: 00007fde6c5ae300 R15: 0000000000022000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:blk_mq_clear_rq_mapping block/blk-mq.c:3052 [inline] RIP: 0010:blk_mq_free_rqs+0x377/0x860 block/blk-mq.c:3100 Code: 0f 85 4c 03 00 00 48 8b 44 24 20 48 8b 48 28 83 f9 3f 0f 87 53 4c d4 04 48 8b 44 24 08 41 bc 00 10 00 00 49 d3 e4 4c 03 24 24 <0f> b6 00 4c 89 64 24 10 84 c0 74 08 3c 03 0f 8e 07 03 00 00 48 8b RSP: 0018:ffffc9000301fac0 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 000000006e550000 RCX: 0000000000000004 RDX: 1ffff110037b0212 RSI: ffff88801bd81000 RDI: ffffea0001b95428 RBP: ffff88801a6a0800 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88806e560000 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 00007fde6c5ae700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fde6b478210 CR3: 0000000019d75000 CR4: 0000000000350ee0 ---------------- Code disassembly (best guess): 0: 0f 85 4c 03 00 00 jne 0x352 6: 48 8b 44 24 20 mov 0x20(%rsp),%rax b: 48 8b 48 28 mov 0x28(%rax),%rcx f: 83 f9 3f cmp $0x3f,%ecx 12: 0f 87 53 4c d4 04 ja 0x4d44c6b 18: 48 8b 44 24 08 mov 0x8(%rsp),%rax 1d: 41 bc 00 10 00 00 mov $0x1000,%r12d 23: 49 d3 e4 shl %cl,%r12 26: 4c 03 24 24 add (%rsp),%r12 * 2a: 0f b6 00 movzbl (%rax),%eax <-- trapping instruction 2d: 4c 89 64 24 10 mov %r12,0x10(%rsp) 32: 84 c0 test %al,%al 34: 74 08 je 0x3e 36: 3c 03 cmp $0x3,%al 38: 0f 8e 07 03 00 00 jle 0x345 3e: 48 rex.W 3f: 8b .byte 0x8b